Class 8

Samacheer Kalvi 8th Science Solutions Term 1 Chapter 7 Plant Kingdom

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Tamilnadu Samacheer Kalvi 8th Science Solutions Term 1 Chapter 7 Plant Kingdom

Samacheer Kalvi 8th Science Solutions Plant Kingdom Text Book Exercises

I. Choose the correct answers

Question 1.
Solanum trilobatum is the binomial name of Thoothuvalai. Here the word ‘Solanum’ refers to …………….
(a) Species
(b) Genus
(c) Class
(d) Orders
Answer:
(b) Genus

Question 2.
…………….. is an example for colonial form of algae.
(a) Oscillatoria
(b) Nostoc
(c) Volvox
(d) Chlorella
Answer:
(c) Volvox

Question 3.
Floridean starch is a reserve food material of …………….
(a) Chloroplyceae
(b) Phaeophyceae
(c) Rhodophyceae
(d) Cyanophyceae
Answer:
(c) Rhodophyceae

Question 4.
The edible mushroom is …………….
(a) Polyporus
(b) Agaricus
(c) Pennicillium
(d) Aspergillus
Answer:
(b) Agaricm

Question 5.
Soil erosion is prevented by …………….. plants.
(a) Algae
(b) Fungi
(c) Bryophytes
(d) Pteridophytes
Answer:
(c) Bryophytes

Question 6.
The first vascular cryptogams in land plants are …………….
(a) Bryophytes
(b) Pteridophytes
(c) Gymnosperm
(d) Angiosperm
Answer:
(b) Pteridophytes

Question 7.
The well – developed sporophytic plant body is seen in ……………..
(a) Bryophytes
(b) Pteridophytes
(c) Gymnosperms
(d) Angiosperms
Answer:
(c) Gymnosperms

Question 8.
Binominal Nomenclature was first introduced in the year of ……………
(a) 1970
(b) 1975
(c) 1978
(d) 1623
Answer:
(d) 1623

Question 9.
Penicillin is an antibiotic, which is extracted from
(a) Algae
(b) Fungi
(c) Bryophytes
(d) Pteridophytes
Answer:
(b) Fungi

II. Fill in the blanks

  1. The word‘Taxonomy’is derived from …………….
  2. Binomial Nomenclature was first introduced by …………….
  3. The book “Genera Plantarum” was written by ……………..
  4. Monocotyledon seeds bear only …………….. cotyledon.
  5. Brown algae belongs to ……………. class.
  6. Agar Agar is obtained from ……………. algae.
  7. The reserve food material of fungi are and …………….
  8. The first true land plant is …………….
  9. Xylem and phloem are absent in ……………. plants.
  10. Reticulate venation is present in ……………. plants.

Answer:

  1. Greek
  2. Gaspard Bauhin
  3. Bentham and Hooker
  4. One
  5. Phaeophyceae
  6. Red
  7. Glycogen, oil
  8. Pteridophyte
  9. Bryophyte
  10. Dicot

III. True or False

Question 1.
In polypetalae, the petals are free.
Answer:
True.

Question 2.
Binomial name should contains more than two words.
Answer:
False.
Correct statement:
Binomial name should contain two words.

Question 3.
Artificial system of classification is based on the vegetative characters of the plant.
Answer:
False.
Correct statement:
Artificial system of classification is based on the morphological characters of the plant.

Question 4.
Cell wall of fungi is made up of chitin.
Answer:
True.

Question 5.
Pinus is a closed seeded plant.
Answer:
False.
Correct statement:
Pinus is a naked seeded plant.

Question 6.
All bryophytes are hydrophytes.
Answer:
False.
Correct statement:
All bryophytes are amphibians.

Question 7.
Dicotyledons have well developed characters than the monocotyledons.
Answer:
False.
Correct statement:
Monocotyledons have well developed characters than the dicotyledons.

Question 8.
Mosses are the well developed plant in bryophytes.
Answer:
True.

Question 9.
The dominant phase of the bryophytes is sporophytes.
Answer:
False.
Correct statement:
The dominant phase of the bryophytes is gametophyte.

Question 10.
The dominant phase of the pteridophytes is diploid(2n).
Answer:
True.

Question 11.
Seeds of angiosperm are produced inside the ovary.
Answer:
True.

Question 12.
In gymnosperms ovules are developed from the flowers.
Answer:
False.
Correct statement:
In gymnosperms, ovules are developed from the seeds.

IV. Match the following

Question 1.
Which of the following pairs are in correct?

(a) Laminaria Iodins
(b) Nostoc N2 fixation
(c) Polysiphonia Green algae
(d) Rhodophyceae Fucoxanthin

(a) a, b, c
(b) c, d
(c) a, c, d
(d) a ,b ,c, d

Answer:
(b) c, d

Question 2.
Find out the correct pairs:

(a) Phyllanthus amarus Euphorbiaceae
(b) Solanum trilobatum Solanaceae
(c) Acalypha indica . Malvaceae
(d) Aegle marmelos Rutaceae

(a) a, b,
(b) c, d
(c) a,b, c,
(d) a,b, d
Answer:
(b) a,b, d

Question 3.
Which of the following characters are not suitable to angiosperm?
(a) Reticulate / parallel venation, closed seeded plants, sieve tubes are present in phloem.
(b) Seeds are open, ovary is not present, gametes are produced in cones.
(c) Tracheids are the conducting cells, companion cells not are present in phloem.
(d) Trimerous or tetramerous, closed seed, seed with seed coat, bears fruit.

(a) a, b
(b) b, c
(c) e, d
(d) a, d
Answer:
(b) b, c

Question 4.
Which of the following sequences are correct
(a) In Bryophytes – Gametophytes – Sex organ – Gamete fusion – Zygote – Spore mother cell – spore – Thallus.
(b) In Angiosperm – pollination – fertilization – zygote – new plant.
(c) In Gymnosperm – male cone, and female cone – microspore and megaspore – Zygote – new sporophytes plant.
(d) In pteridophytes – pollination by wind, fertilization in the presence of water – zygote prothallus, new plant.
(1) a, b, c
(2) a, b
(3) c, d
(4) b, d
Answer:
(2) a, b

Question 5.
Match column I with coloumn II

Column I Column II
A Penicillium chrysogenum 1. Blast disease of paddy.
B Gingko biloba 2. Ornamental plants
C Araucaria bidwilli 3. Athlete foot.
D Tineapedis 4. Penicillin
E Pyricularia oryzae 5. Living fossil

(a) A – 4, B – 5, C – 2, D – 3, E – 1
(b) A – 4, B – 5, G – 1, D – 2, E – 1
(c) A – 3, B – 2, C – 4, D – 5, E – 1
(d) A – 4, B – 2, C – 1, D – 5, E – 3
Answer:
(a) A – 4, B – 5, C – 2, D – 3, E – 1

V. Answer the following questions shortly

Question 1.
Define Thallus.
Answer:
Thallus refers to a plant body which is not differentiated into roots, stem and leaves. Example: Algae.

Question 2.
What is mean by Binomial Nomenclature? Give example.
Answer:
The naming of an organisms with two words are known as Binomial Nomenclature. For example, the binomial name of mango is Mangifera indica. Here the first word Mangifera refers to the genus name and the second word indica to the species name.

Question 3.
Write any two points of dicotyledons.
Answer:

  1. Seed has two cotyledons.
  2. Plants have tap root system, leaves with reticulate venation.
  3. Flowers are tetramerous or pentamerous. Calyx and corolla are well differentiated.
  4. Pollination occurs mostly by insects.

Question 4.
Seeds of gymnosperm plants are naked. Why?
Answer:
In gymnosperms, ovules are borne on megasporophylls and no flowers are produced. Therefore the seeds are described as naked. They are open seed bearing plants.

Question 5.
Write any two economic importance of fungi.
Answer:

  1. Mushrooms contain rich protein, minerals and are edible. Example: Agaricus.
  2. The antibiotic penicillin is got from the fungus penicillium notatum other antibiotics like gentamycin, erythromycin are also got from fungi.

VI. Answers the following questions in brief

Question 1.
Write short notes about natural system of classification.
Answer:

  1. In this system, plants are classified on the basis of several characters. Bentham and Hooker’s classification is an example of Natural System of Classification.
  2. This system of classification is based on morphological.
  3. This classification is widely used in many Herbaria and botanical gardens all over the world.
  4. Bentham and Hooker published their Natural system of Classification in their book named Genera Plantarum in 3 volumes.

Question 2.
Write any three economic importance of algae.
Answer:
1. Agriculture : Some of the blue green algae are essential for the fixing of atmospheric nitrogen into the soil, which increases the fertility of the soil, example Nostoc, Anabaena.

2. Agar Agar : Agar Agar is extracted from some red algae, namely Gelidium, Gracillaria, etc., which is used to prepare growth medium in laboratories.

3. Iodine : Iodine is obtained from brown algae like Laminaria (kelp).

Question 3.
Write the differences between algae and fungi.
Answer:
Algae:

  • Algae are autotrophs.
  • It has pigments.
  • Reserve food material is starch.
  • Some algae are prokaryotic in nature, example: Cyanobacteria (Nostac, Anabenae)

Fungi:

  • Fungi are heterotrophs.
  • It has no pigments
  • Reserve food materials are glycogen and oil.
  • All are eukaryotic nature, example: Agaricus

Question 4.
How many classes are there in Bryophytes? What are they?
Answer:
Bryophytes are classified into 3 classes.

  • Class I: Hepaticae (Liverworts) Example: Riccia.
  • Class II: Anthocerotae (Homworts) Example : Anthoceros
  • Class III : Musci (Mosses) Example: Funaria

Question 5.
Write any four characters of pteridophytes.
Answer:

  1. The main plant body is sporophytes, which is the dominant phase, differentiated into true root, stem and leaves.
  2. Sporophytes reproduce by means of spores. Spores are produced in sporangium.
  3. The sporangia bearing leaves are called sporophyll.
  4. Most of the plants produce only one type of spore, it may be either microspore or megaspore (homosporous).

VII. Answers the following questions in detail

Question 1.
Draw the outline of Bentham and Hookers system classification.
Answer:
Outline of Bentham and Hooker’s system of classification:
Seeded plants (Division):

(i) Dicotyledonae (Class I)

1. Polypetalae (Sub class I)

  • Thalamiflorae
  • Disciflorae
  • Caliciflorae

2. Synpetalae (Sub class II)

  • Inferae
  • Heteromerae
  • Bicarpellatae

3. Monochlamydeae (Sub class III)

  • Series 8 Family 36)

(ii) Gymnospermae (Class II) (3 families)

(iii) Monocotyledonae (Class III) (Series 8 Family 36)

Question 2.
Write any five differences between monocot and dicot plants.
Answer:
Monocots:

  • Seeds have a single cotyledon.
  • Leaves show parallel venation
  • They have fibrous root system.
  • Flowers are trimerous. Example : Paddy

Dicots:

  • Seeds have two cotyledons.
  • Leaves show reticulate venation.
  • They have tap root system.
  • Flowers are tetra or pentamerous. Example : Mango

Question 3.
Write differences between Gymnosperm and Angiosperm.
Answer:

Gymnosperm:

  • They reproduce by production of cones.
  • Pollination is by wind.
  • They are naked seed bearing plants.
  • The xylem lacks vessels and phloem lacks sieve tubes.
  • They have two phases in its life cycle. (Sporophyte & Gametophyte).

Angiosperm:

  • They produce flowers.
  • Pollination takes place by wind, water, insects etc.
  • They are closed seed bearing plants.
  • Xylem and phloem and well developed.
  • The sporophyte is the dominant phase. Gametophytic phase is much reduced in angiosperms.

Question 4.
Write the economic importance of Gymnosperms.
Answer:

  1. Woods of many conifers are used in the paper industries, example Pinus, Agathis.
  2. Conifers are the sources of soft wood for construction, packing and plywood industry example Cedrus, Agathis.
  3. Turpentine is an essential oil used for paint preparation extracted from the resin of Pinus. It is also used medicinally for relief from pain and bronchitis etc.
  4. Seeds of Pinus gerardiana are edible.
  5. Ephedrine is an alkaloid extracted from Ephedra. It cures asthma and respiratory problems.
  6. Araucaria bidwillii is an ornamental plant.

Question 5.
Write the names of medicinal plants and explain their uses.
Answer:
Medicinal plants and their uses:
1. Acalypha indica (Kuppaimeni):

  • The paste obtained from the leaves of this plant is used to cure the bums on the skin.
  • The juice of this plant leaves is mixed with lemon juice to cure ringworm.

2. Aegle marmelos (Vilvam):

  • The unripe fruit of this tree is used to treat indigestion.
  • It is used to cure chronic, diarrhoea and dysentery.

3. Solanum trilobatum:

  • The leaves and fruits of this plant cure cough and cold.
  • It is widely used in the treatment of tuberculosis and bronchial asthma.

4. Phyllanthus amarus (Keezhanelli):

  • The entire plant is used for the treatment of jaundice.
  • It gives additional strength to human liver and used to treat other liver disorders.

5. Aloe vera (Sothu katrazhai):

  • Leaves of this plant is used to cure piles and inflammations on the skin.
  • It cures peptic ulcer.

VIII. Assertion and Reason

Question 1.
Assertion (A) : Penicillin is an antibiotic extracted from Penicillium notation.
Reason (R) : It can kill (or) inhibits the growth of the other micro organism.
(a) Both A and R True, R explains A
(b) A only correct, R doesn’t explain A
(c) A True, R explains A
(d) Both A and R False.
Answer:
(a) Both A and R True, R explains A

Question 2.
Assertion (A): Artificial system of classification is otherwise called sexual system of classification.
Reason (R) : Artificial system of classification is based on the nature of the vegetative characters.
(a) Both A and R correct
(b) Both A and R incorrect
(c) A is correct R is incorrect
(d) A is incorrect and R is correct
Answer:
(c) A is correct R is incorrect

Question 3.
Assertion (A): Bryophytes are called Amphibians of the plant kingdom.
Reason (R) : Bryophytes are land plants but they need water for the completion of their life cycle.
(a) A correct R correct
(b) A incorrect R correct
(c) A and R correct R explain A
(d) A and R incorrect
Answer:
(c) A and R correct R explains A

Samacheer Kalvi 8th Science Solutions Plant Kingdom Additional Questions

I. Choose the correct answer

Question 1.
……………. is a blue green algae.
(a) Chlorella
(b) Oscillatoria
(c) Chara
(d) Laminaria
Answer:
(d) Laminaria

Question 2.
Polvsiohonia is a …………… alga.
(a) Red
(b) Brown
(c) Green
(d) Blue green
Answer:
(a) Red

Question 3.
…………… is used in space travel.
(a) Chlorella
(b) Chlamydomonas
(c) Volvox
(d) Laminaria
Answer:
(a) Chlorella

Question 4.
……………. is an edible algae.
(a) Spirulina
(b) Gelidium
(c) Nostoc
(d) Volvox
Answer:
(a) Spirulina

Question 5.
Tikka disease is seen in ……………..
(a) paddy
(b) Ground nut
(c) Mango
(d) Maize
Answer:
(b) ground nut

Question 6.
Classification of algae was given by …………….
(a) Martin
(b) Alexopoules
(c) Fritsch
(d) Bentham & Hooker
Answer:
(c) Fritsch

Question 7.
…………… is a hallucinogenic fungus.
(a) Colletotrichum
(b) Claviceps
(c) Cercospora
(d) Albugo
Answer:
(b) Claviceps

Question 8.
…………… is not a fungal disease.
(a) Athlet’s foot
(b) Foot and mouth
(c) Dandruff
(d) Ringworm
Answer:
(b) Foot and mouth

Question 9.
Horse tail refers to …………….
(a) Equisetum
(b) Dryopteris
(c) Lycopodium
(d) Nephrolepis
Answer:
(a) Equisetum

Question 10.
Coralloid roots are seen in …………….
(a) Pimis
(b) Cycas
(c) Gingko
(d) Gnetum
Answer:
(b) Cycas

II. Fill in the blanks

  1. Minute algae floating on the surface of water are called …………..
  2. ……………… is an example of symbiosis between algae & fungi.
  3. The book writtin by Linnaeus is titled …………….
  4. Largest Herbarium of India is in ………………
  5. The root like structure in bryophytes is called ………………
  6. …………….. are the simplest group of land plants.
  7. ……………… is a bryophyte which is commonly used in nurseries.
  8. In bryophytes spore is the first cell of the ……………… generation.
  9. Club moss refers to ……………….
  10. An alkaloid got from gymnosperm is ………………
  11. ……………… is a essential oil got from pinus.
  12. The plant ……………… is used for treatment of jaundice.
  13. Special roots present in parasites are called ……………….
  14. The male and female sex organs in bryophytes are called as ……………… and ……………… respectively.
  15. ……………… got from algae is used to prepare growth medium in laboratories.

Answer:

  1. Phytoplanktons
  2. Lichens
  3. Species Plantarum
  4. Kolkata
  5. Rhizoid
  6. Bryophytes
  7. Sphagnum
  8. Gametophytic
  9. Lycopodium
  10. Ephedrine
  11. Turpentine
  12. Phyllanthus amarus
  13. Haustoria
  14. Antheridium, archegonium
  15. Agar Agar

III. True or False – if false give the correct statement

Question 1.
Monocotyledonae leaves have reticulate venation.
False.
Correct statement:
Dicotyledonae leaves have reticulate venation. Monocotyledonae leaves have parallel venation.

Question 2.
Carolus linnaeus published their Natural System of Classification.
False.
Correct statement:
Bentham and Hooker published their Natural System of Classification.

Question 3.
Biomial name was first introduced by Gaspard Bauhin.
True.

Question 4.
Agar Agar is extracted from red algae.
True.

Question 5.
Blue green algae increases the fertility of the soil.
True.

Question 6.
Cell wall of algae is made up of a chemical substance called chitin.
False.
Correct statement:
Cell wall of fungi is made up of a chemical substance called chitin.

Question 7.
Saprophytes grow up on the dead and decay matters.
True.

Question 8.
Erymothercium ashbyii are used to produce vitamin Br
True.

Question 9.
Button mushroom cause allergy to children.
False.
Correct statement:
Aspergillus species cause allergy to children.

Question 10.
Reserve food materials of fungi is starch.
False.
Correct statement:
Reserve food materials of fungi is glycogen and oil.

IV. Match the following

Question 1.

i Solanum trilobatum (a) Fungi
ii Vitamin B2 (b) Rhizopus
iii Saprophyte (c) Laminaria
iv Fodder (d) TB

Answer:

i. d
ii. a
iii. b
iv. c

Question 2.

i Pyricularia (a) Mosses
ii Cercospora (b) Blast disease
iii Protonema (c) Tikka disease
iv Dryopteris (d) Fem

Answer:

i. b
ii. c
iii. a
iv. d

Question 3.

i Araucaria (a) Bryophyte
ii Riccia (b) Fungi
iii Marsilea (c) Gymnosperm
iv Ashbya (d) Pteridophyte

Answer:

i. c
ii. a
iii. d
iv. b

V. Assertion and Reason

Direction:
In each of the following questions, a statement of Assertion is given and a corresponding statement of Reason is given just below it. Of the four statements, given below, mark one as the correct answer.
(a) If both Assertion and Reason are true and Reason is the correct explanation of Assertion.
(b) If both Assertion and Reason are true and Reason is not the correct explanation of Assertion.
(c) If Assertion is true but Reason is false.
(d) If both Assertion and Reason are false.

Question 1.
Assertion : Fungi are considered as thallophytes.
Reason : The plant body is made up of hyphae.
Answer:
(a) Both Assertion and Reason are true and Reason is the correct explanation of Assertion

Question 2.
Assertion : The sporophyte of bryophytes is borne on the gametophyte.
Reason : The sporophyte is the dominant phase.
Answer:
(c) Assertion is true but Reason is false

Question 3.
Assertion : In pteridophytes, gametophyte is the dominant phase.
Reason : They reproduce by spore production.
Answer:
(d) Both Assertion and Reason are false

Question 4.
Assertion : Gymnosperms are more developed than monocots.
They produce closed seeds.
Answer:
(d) Both Assertion and Reason are false

VI. Very short Answers

Question 1.
Name the types of classification.
Answer:
There are four types of classification.

  1. Artificial system of classification
  2. Natural system of classification
  3. Phylogenetic system of classification
  4. Modem system of classification.

Question 2.
What are phytoplankton?
Answer:
Some algae are very minute and float on the surface of the water. These algae are called Phytoplankton.

Question 3.
Mention two forms of algae with examples.
Answer:

  1. Colonial form – Example: Volvolx.
  2. Unicellular form (motile) – Example: Chlamydomonas

Question 4.
Mention two fungal diseases in human beings.
Answer:
Dandruff and ring worm.

Question 5.
Why are byrophytes called as amphibians of the plant kingdom?
Answer:
Water is essential for bryophytes to complete their life cycle. So they are called as amphibians of the plant kingdom.

Question 6.
Write two uses of bryophytes.
Answer:

  1. Bryophytes prevent soil erosion.
  2. Sphagnum can absorb large amount of water. Hence it is used by gardeners in nurseries.

Question 7.
How are gymnosperms classified?
Answer:

  1. Cycadaceae
  2. Coniferae
  3. Gnetaceae

VI. Short Answer

Question 1.
Mention two differences between bryophytes and pteridophytes.
Answer:

S. No Bryophytes Pteridophytes
1. Plant body cannot be differentiated into root, stem and leaf. Plant body can be differentiated into root, stem and leaf.
2. Vascular tissues are absent. Vascular tissues are present.

Question 2.
Mention any four fungal diseases in plants
Answer:

  1. Wilt disease of cotton
  2. Tikka disease of ground nut
  3. White rust of radish
  4. Red rot of sugarcane.

Question 3.
Mention two salient features of algae.
Answer:

  1. Algae are chlorophyll bearing simple, primitive plants and are autotrophs.
  2. Algae belongs to thallophyta, and the plant body of algae are called thallus. i.e. the plant body is not differentiated into root, stem and leaf.

Question 4.
What is artificial system of classification.
Answer:
This is the earliest system of classification in plants. Plants are classified on the basis of one or few morphological characters. The most famous artificial system of classification is Linnaeus classification which was proposed by Carolus Linnaeus.

Question 5.
What is taxonomy?
Answer:
Taxonomy is the branch of biology that deals with the study of identification, classification, description and nomenclature of living organisms.

VIII. Long Answer

Question 1.
Write the classification of algae with type of reserve food, pigments and examples for each type.
Answer:

SI. No Class Types of Pigments Reserve food material Example
1. Blue green algae (Cyanophyceae) Phycocyanin Cyanophycean Starch Oscillatoria
2. Green algae (Chlorophyceae) Chlorophyll Starch Chylamydomonas
3. Brown algae (Phaeophyceae) Fucoxanthin Laminarian starch and Manitol Laminaria
4. Red algae (Rhodophyceae) Phycoerythirin Floridian Starch Polysiphonia

Question 2.
Answer:
1. Antibiotic :
Penicillin (Penicillium notatum), Neomycin, Gentamycin, Erythromycin are some antibiotics obtained from fungi, which cure variable diseases.
Samacheer Kalvi 8th Science Solutions Term 1 Chapter 7 Plant Kingdom 1

2. Food:
Mushroom contains rich protein and minerals. The most common edible mushroom is Agaricus. (Button mushroom).
Samacheer Kalvi 8th Science Solutions Term 1 Chapter 7 Plant Kingdom 2

3. Vitamins :
Fungus like Ashbya gospii and Erymothecium ashbyii are used to produce vitamin B? (riboflavin).
Samacheer Kalvi 8th Science Solutions Term 1 Chapter 7 Plant Kingdom 3

4. Alcohol:
Fungus like yeast contain enzymes invertase and zymase, which ferment the sugar molasses into alcohol.

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Samacheer Kalvi 8th Science Solutions Term 2 Chapter 3 Air

You can Download Samacheer Kalvi 8th Science Book Solutions Guide Pdf, Tamilnadu State Board help you to revise the complete Syllabus and score more marks in your examinations.

Tamilnadu Samacheer Kalvi 8th Science Solutions Term 2 Chapter 3 Air

Samacheer Kalvi 8th Science Air Text Book Exercises

I. Choose the best answer

Question 1.
Which of the following is true about oxygen?
(a) Completely burning gas
(b) Partially burning gas
(c) Doesn’t support burning
(d) Supports burning
Answer:
(d) Supports burning

Samacheer Kalvi 8th Science Solutions Term 2 Chapter 3 Air

Question 2.
Aerated water contains –
(a) air
(b) oxygen
(c) carbon dioxide
(d) nitrogen
Answer:
(c) carbon dioxide

Question 3.
Solvay process is a method to manufacture –
(a) lime water
(b) aerated water
(c) distilled water
(d) sodium carbonate
Answer:
(d) sodium carbonate

Question 4.
Carbon dioxide with water changes –
(a) blue litmus to red
(b) red litmus to blue
(c) blue litmus to yellow
(d) doesn’t react with litmus
Answer:
(a) blue litmus to red

Question 5.
Which of the following is known as azote?
(a) Oxygen
(b) Nitrogen
(c) Sulphur
(d) Carbon dioxide
Answer:
(b) Nitrogen

II. Fill in the blanks

  1. ……………. is called as vital life.
  2. Nitrogen is ……………. than air.
  3. ……………. is used as a fertilizer.
  4. Dry ice is used as a …………….
  5. The process of conversion of iron into hydrated form of oxides is called …………….

Answer:

  1. Oxygen
  2. lighter
  3. Nitrogen
  4. refrigerant
  5. rusting

III. Match the following

Question 1.

  1. Nitrogen – Respiration in living animals
  2. Oxygen – Fertilizer
  3. Carbon dioxide – Refrigerator
  4. Dry ice – Fire extinguisher

Answer:

  1. Nitrogen – Fertilizer
  2. Oxygen – Respiration in living animals
  3. Carbon dioxide – Fire extinguisher
  4. Dry ice – Refrigerator

Samacheer Kalvi 8th Science Solutions Term 2 Chapter 3 Air

IV. Answer briefly

Question 1.
What are the sources of oxygen?
Answer:

  1. Atmospheric air, water.
  2. Plants and animals.
  3. Minerals in the form of silicates, carbonates, oxides.

Question 2.
Mention the physical properties of oxygen.
Answer:
Physical properties of oxygen:

  1. Oxygen is a colorless, odorless and tasteless gas.
  2. It is a poor conductor of heat and electricity
  3. Oxygen dissolves readily in cold water.
  4. It is denser than air.
  5. It can be made into liquid (liquefied) at high pressure and low temperature.
  6. It supports combustion.

Question 3.
List out the uses of nitrogen.
Answer:
Uses of nitrogen:

  1. Liquid nitrogen is used as a refrigerant.
  2. It provides an inert atmosphere for conducting certain chemical reactions.
  3. It is used to prepare ammonia (by Haber’s process) which is then converted into fertilizers and nitric acid.
  4. It is used for inflating tyres of vehicles.

Question 4.
Write about the reaction of nitrogen with non metals.
Answer:
Nitrogen reacts with non-metals like hydrogen, oxygen etc., at high temperature to form their corresponding nitrogen compounds.
Non-metal + Nitrogen \(\underrightarrow { \Delta } \) Nitrogen compound
Example:
Samacheer Kalvi 8th Science Solutions Term 2 Chapter 3 Air 1

Question 5.
What is global warming?
Answer:
The increased green house effect is caused due to increase in the air pollutants and it results in the average increase of temperature of the atmosphere. This is called as Global warming.

Samacheer Kalvi 8th Science Solutions Term 2 Chapter 3 Air

Question 6.
What is dry ice? What are its uses?
Answer:

  1. Solid carbon dioxide, called as dry ice is used as a refrigerant.
  2. The gas is so cold that moisture in the air condenses on it, creating a dense fog which is used in stage shows and movie effects.

V. Answer in detail

Question 1.
What happens when carbon dioxide is passed through lime water? Write the equation for this reaction.
Answer:
When a limited amount of CO2 is passed through lime water, it turns milky due to the formation of insoluble calcium carbonate.
Ca(OH)2 + CO2 → CaCO3 + H2O
When an excess amount of CO2 is passed through lime water, it first turns milky and the milkyness disappears due to the formation of soluble calcium hydrogen carbonate, Ca(HCO3)2.

Question 2.
Name the compounds produced when the following substances burn in oxygen:

  1. Carbon
  2. Sulphur
  3. Phosphorous
  4. Magnesium
  5. Iron
  6. Sodium

Answer:

  1. Carbon dioxide (CO2)
  2. Sulphur dioxide (SO2)
  3. Phosphorus trioxide (P2O3) (or) Phosphorus pentoxide (P2O5)
  4. Magnesium Oxide (MgO)
  5. Iron Oxide (Fe2O3)
  6. Sodium Oxide (Na2O)

Question 3.
How does carbon dioxide react with the following?

  1. Potassium
  2. Lime water
  3. Sodium hydroxide

Answer:
1. Potassium combine with CO2 to form potassium carbonate.
4K + 3CO2 → 2K2CO3 + C

2. When a limited amount of CO2 is passed through lime water, it turns milky due to the formation of insoluble calcium carbonate.
Ca(OH)2 + CO2 → CaCO3 + H2O
(Calcium carbonate)
Sodium hydroxide (base) is neutralized by carbon dioxide (acidic) to form sodium carbonate (salt) and water.
Samacheer Kalvi 8th Science Solutions Term 2 Chapter 3 Air 2
Question 4.
What are the effects of acid rain? How can we prevent them?
Answer:
Acid rain affects us in many ways. Some of the consequences are given below.

  1. It irritates eyes and skin of human beings.
  2. It inhibits germination and growth of seedlings.
  3. It changes the fertility of the soil, destroys plants and aquatic life.
  4. It causes corrosion of many buildings, bridges, etc.

Preventive measures:
Acid rain and its effects can be controlled by the following ways.

  1. Minimizing the usage of fossil fuel such as petrol, diesel etc.
  2. Using CNG (Compressed Natural Gas).
  3. Using non – conventional source of energy.
  4. Proper disposal of the industrial wastes.

VI. Higher Order Thinking Questions

Question 1.
Soda bottle bursts sometimes when it is opened during summer. Why?
Answer:

  1. In soda bottle carbon dioxide gas is dissolved in water under pressure.
  2. The gas in the bottle expands.
  3. Hence, the pressure inside the bottle increases.
  4. Thus the bottle may burst in hot summer.

Question 2.
It is said that sleeping beneath the tree during night is bad for health. What is the reason?
Answer:
During night trees absorb oxygen and release carbon dioxide. Therefore, anyone who sleeps under tree, will not get oxygen, which can cause breathing problems, suffocation etc.

Samacheer Kalvi 8th Science Solutions Term 2 Chapter 3 Air

Question 3.
Why does the fish die when it is taken out of water?
Answer:

  1. Gills are richly supplied with blood capillaries and can readily absorb the oxygen dissolved in water.
  2. When fishes are taken out of water, the supply of oxygen to the fishes is cut as the fishes cannot absorb and breathe using the oxygen present in the atmosphere.
  3. Hence they die, when it is taken out of water.

Question 4.
How do astronauts breathe when they go beyond earth’s atmosphere?
Answer:

  1. Astronauts cannot breathe in space unless they carry their own oxygen with them.
  2. They can make their own oxygen by using energy from the solar arrays to split hydrogen and oxygen from water.

Do you know?

Question 1.
Nowadays nitrogen is used as a substitute for compressed air in tyres. Have you noticed it? Why do people prefer nitrogen instead of compressed air in tyres?
Answer:
It is because nitrogen tyres hold pressure longer as compared to compressed air. Nitrogen gas in the tyre escapes more slowly than compressed air does.

Samacheer Kalvi 8th Science Air Additional Questions

I. Choose the correct answer

Question 1.
Question 1.
…………… is necessary for all acids.
(a) Nitrogen
(b) CO2
(c) Oxygen
(d) Hydrogen
Answer:
(c) Oxygen

Question 2.
Tri oxygen molecule is known as ……………
(a) hydrogen
(b) oxygen
(c) nitrogen
(d) ozone
Answer:
(d) ozone

Samacheer Kalvi 8th Science Solutions Term 2 Chapter 3 Air

Question 3.
About 78% by volume of air is ……………
(a) Carbon dioxide
(b) Nitrogen
(c) Argon
(d) Oxygen
Answer:
(b) nitrogen

Question 4.
Carbon dioxide gas is ……………
(a) heavier than air
(b) lighter than air
(c) as heavy as air
(d) none of these
Answer:
(a) heavier than air

Question 5.
A gas which neither burns nor supports burning is …………….
(a) Oxygen
(b) Helium
(c) Hydrogen
(d) Carbon dioxide
Answer:
(d) Carbon dioxide

Question 6.
A gas which is used to remove carbon impurities from steel.
(a) Nitrogen
(b) Oxygen
(c) Carbon dioxide
(d) Hydrogen
Answer:
(b) Oxygen

Question 7.
Venus atmosphere consists of roughly 96 – 97% of …………….
(a) Oxygen
(b) Nitrogen
(c) Carbon dioxide
(d) none
Answer:
(c) Carbon dioxide

Samacheer Kalvi 8th Science Solutions Term 2 Chapter 3 Air

Question 8.
Carbon dioxide gas is …………… in nature.
(a) basic
(b) acidic
(c) sweet
(d) none
Answer:
(b) acidic

Question 9.
…………… gas is essential for the proper growth of all plants.
(a) Nitrogen
(b) CO2
(c) Oxygen
(d) none
Answer:
(a) Nitrogen

Question 10.
Lighter metals like Na, K combine with CO2 to form corresponding …………….
(a) Nitrates
(b) Carbonates
(c) Oxide
(d) none
Answer:
(b) Carbonates

II. Fill in the Blanks

  1. …………… exists in nature as silicates, carbonates, oxides and water.
  2. Metals like magnesium, iron and sodium bum with oxygen and give basic …………….
  3. …………… has pH less than 5.6.
  4. CO2 is along with …………… in the manufacture of fertilizers like urea.
  5. CO2, N2O, CH4 and CFC are known as …………….
  6. ……………. is used to prepare soft drinks or aerated drinks.
  7. ……………. is used as a substitute for compressed air in tyres.
  8. Liquid nitrogen is used as a ……………..
  9. Oxygen is used to oxidize …………….
  10. Phosphorous bums with suffocating smell and gives ……………..

Answer:

  1. Oxygen
  2. Oxides
  3. Acid rain
  4. ammonia
  5. Greenhouse gases
  6. CO2
  7. Nitrogen
  8. refrigerant
  9. rocket fuel
  10. Phosphorous pentaoxide

III. Match the following

Question 1.

1. Oxygen (a) Carbon dioxide
2. Azote (b) Nitrogen
3. Solvay process (c) Vital life
4. Gun powder (d) No life

Answer:

  1. c
  2. d
  3. a
  4. b

Samacheer Kalvi 8th Science Solutions Term 2 Chapter 3 Air

Question 2.

1. Nitrogen (a) Acid rain
2. CO2 (b) Global warming
3. Melting of glaciers (c) Volcanic gases
4. Corrosion of bridges (d) Aerated drinks

Answer:

  1. c
  2. d
  3. b
  4. a

IV. True or False – if false give the correct statement

Question 1.
Oxygen is the poor conductor of heat and electricity.
Answer:
True

Question 2.
Nitrogen is about two times more soluble in water then oxygen.
Answer:
False
Correct statement:
Oxygen is about two times more soluble in water than Nitrogen.

Question 3.
Nitrogen is an essential element present in proteins and nucleic acids which are the building blocks of living things.
Answer:
True

Question 4.
Non-metal + Nitrogen \(\underrightarrow { \Delta } \) Nitrogen compound.
Answer:
True

Question 5.
Solid form of CO2 is called as dry ice which undergoes condensation.
Answer:
False
Correct statement:
Solid form of CO2 is called as dry ice which undergoes sublimation.

Question 6.
Acid rain inhibits germination and growth of seedlings.
Answer:
True

Samacheer Kalvi 8th Science Solutions Term 2 Chapter 3 Air

Question 7.
An average increase in the temperature of the atmosphere is called as acid rain.
Answer:
False
Correct statement:
An average increase in the temperature of the atmosphere is called as global warming.

Question 8.
Rain water is actually the purest form of water.
Answer:
True

Question 9.
The increase in the levels of greenhouse gases results in the gradual increase of temperature of the earth’s surface.
Answer:
True

Question 10.
Nitrogen gas is so cold that moisture in the air condenses on it, creating a dense fog.
Answer:
False
Correct statement:
Solid CO2 gas is so cold that moisture in the air condenses on it, creating a dense fog.

V. Assertion and Reason

Question 1.
Mark the correct choice as:
(a) If both assertion and reason are true and the reason is the correct explanation of the assertion.
(b) If both assertion and reason are true, but the reason is not the correct explanation of the assertion.
(c) If the assertion is true, but the reason is false.
(d) If the assertion is false, but the reason is true.

Question 1.
Assertion : Green house gases maintain the temperature.
Reason : Green house gases absorb the infra red rays.
Answer:
(a) Both assertion and reason are true and the reason is the correct explanation of the assertion

Question 2.
Assertion : Carbon dioxide occurs as carbonates in nature.
Reason : Carbon dioxide can exist as a liquid at atmospheric pressure.
Answer:
(c) Assertion is true, but the reason is false.

VI. Answer briefly

Question 1.
What is acid rain?
Answer:
Rain mixed with sulphuric acid is called acid rain.

Question 2.
Name some green house gases.
Answer:
CO2, N2O, CH4, CFC (Chlorofluorocarbon) etc.

Samacheer Kalvi 8th Science Solutions Term 2 Chapter 3 Air

Question 3.
Name the microbe which converts atmospheric nitrogen directly into soluble nitrogen compounds.
Answer:
Bacteria.

Question 4.
Write the reaction of oxygen with hydrocarbons.
Answer:
Hydrocarbon + O2 > CO2 + Water vapour + Heat energy + Light.

Question 5.
Write the reaction of carbon dioxide with lime water.
Ca(OH)2 + CO2 → CaCO3 + H2O.

Question 6.
Write any two preventive measures for acid rain.
Answer:

  1. Using CNG
  2. Proper disposal of the industrial wastes.

Question 7.
Write about the combustible property of Oxygen.
Answer:
Oxygen is a non – combustible gas as it does not bum on its own. It supports the combustion of other substances.

Question 8.
Write any two effects of global warming.
Answer:

  1. Increase in frequency of floods, soil erosion and unseasonal rains.
  2. Loss of biodiversity due to the extinction of coral reefs and other key species.

Samacheer Kalvi 8th Science Solutions Term 2 Chapter 3 Air

Question 9.
What do you mean by aerated water?
Answer:
Aerated water is nothing but carbon dioxide dissolved in water under pressure. This is also called soda water.

Question 10.
Write any two preventive measures of global warming.
Answer:

  1. Reduction in the use of fossil fuels.
  2. Restricting the use of CFC’s.

Question 11.
Write the reaction of oxygen with non – metals.
Answer:
Oxygen reacts with various non – metals like hydrogen, nitrogen, carbon, sulphur, phosphorus etc., to give corresponding non – metallic oxides which are generally acidic in nature.
Non – metal + Oxygen → Non – metallic oxide
Example:
C + O2 → CO2

Question 12.
Write a note on rusting process.
Answer:
The process of conversion of iron into its hydrated form of oxide in the presence of air and moisture (humid atmosphere) is called rusting. Rust is hydrated ferric oxide.
4Fe + 3O2 → 2Fe2O3
Fe2O3 + X H2O → 2Fe2O3 . X H2O
(X = Number of water molecules which is variable).

Question 13.
Write the reaction of nitrogen with metals.
Answer:
Nitrogen reacts with metals like lithium, calcium, magnesium etc., at high temperature to form their corresponding metal nitrides.
Metal + Nitrogen \(\underrightarrow { \Delta } \) Metal nitride
Example:
Samacheer Kalvi 8th Science Solutions Term 2 Chapter 3 Air 3

Question 14.
Write about occurrence of carbon dioxide.
Answer:
Carbon dioxide is present in air to the extent of about 0.03% in volume. It is evolved by the plants and animals during respiration and is produced during fermentation reactions. Much of the naturally occurring CO2 is emitted from the magma through volcanoes. CO2 may also originate from the bio – degradation of oil and gases. Human CO2 emissions upset the natural balance of the carbon cycle.

Samacheer Kalvi 8th Science Solutions Term 2 Chapter 3 Air

Question 15.
Write the reaction of carbon dioxide with metals.
Answer:
Lighter metals like sodium, potassium and calcium, combine with CO2 to form corresponding carbonates whereas magnesium gives its oxide and carbon.
Example :
Samacheer Kalvi 8th Science Solutions Term 2 Chapter 3 Air 4

Question 16.
What are the effects of global warming?
Answer:

  1. Melting of ice cap and glaciers.
  2. Increase in frequency of floods, soil erosion and un – seasonal rains.
  3. Loss of biodiversity due to the extinction of coral reefs and other key species.
  4. Spreading of waterborne and insectborne diseases.

Question 17.
Complete the following:
Samacheer Kalvi 8th Science Solutions Term 2 Chapter 3 Air 5
Answer:

  1. Natural fixation
  2. From leguminous plants
  3. From ammonia and ammonium salts
  4. From nitric acid and nitrate salts

Question 18.
What is green house effect?
Answer:

  1. Certain gaseous molecules present in the atmosphere absorb the infra red rays and reradiate the heat in all directions.
  2. Hence, these gases maintain the temperature of earth’s surface.
  3. The gases which absorb these radiations are called green house gases and this effect is called green house effect.

Question 19.
Complete the table:

Metal Condition Product formed
K Room temperature (i)
Ca (ii) CaO
(iii) Even at high temperature No action
Fe High temperature (iv)

Answer:

  1. Potassium oxide (K2O)
  2. Heating slightly
  3. Au or Pt
  4. Iron Oxide (Fe3O4)

VII. Answer in detail

Question 1.
Explain the uses of oxygen.
Answer:
Uses of oxygen:

  1. It is used as oxy – acetylene light for cutting and welding metals.
  2. It is used to remove carbon impurities from steel.
  3. Plants and animals use oxygen from the air for respiration.
  4. It is used to oxidize rocket fuel.
  5. It is used for artificial respiration by scuba divers, mountaineers, astronauts, patients etc.
  6. Mixed with powdered charcoal it is used as explosives.
  7. It is used in the synthesis of methanol and ammonia.

Question 2.
Write the physical properties of nitrogen.
Answer:

  1. Physical properties of nitrogen
  2. It is a colorless, tasteless and odorless gas.
  3. It is slightly lighter than air.
  4. It is slightly soluble in water.
  5. Nitrogen becomes a liquid at low temperature and looks like water. When it freezes, it becomes a white solid.
  6. It is neutral to litmus like oxygen.

Samacheer Kalvi 8th Science Solutions Term 2 Chapter 3 Air

Question 3.
Write the uses of nitrogen.
Answer:
Uses of Nitrogen:

  1. Liquid nitrogen is used as a refrigerant.
  2. It provides an inert atmosphere for conducting certain chemical reactions.
  3. It is used to prepare ammonia (by Haber’s process) which is then converted into fertilizers and nitric acid.
  4. It is used for inflating tyres of vehicles.
  5. It is used for filling the space above mercury in high temperature thermometer to reduce the evaporation of mercury.
  6. Many explosives such as TNT (Trinitrotoluene), nitroglycerin and gun powder contain nitrogen.
  7. It is used for the preservation of fresh foods, manufacturing of stainless steel, reducing fire hazards and as part of the gas in incandescent light bulbs.

Question 4.

  1. Explain the physical properties of carbon dioxide.
  2. Write the preventive measures to control the effect of global warming.

Answer:
1. Physical properties of carbon dioxide:

  • Carbon dioxide is a colorless and odorless gas.
  • It is heavier than air.
  • It does not support combustion.
  • It is fairly soluble in water and turns blue litmus slightly red. So it is acidic in nature.
  • It can easily be liquefied under high pressure and can also be solidified. This
  • solid form of CO2 is called dry ice which undergoes sublimation.

2. Preventive measures:

  • Reduction in the use of fossil fuels.
  • Controlling deforestation.
  • Restricting the use of CFCs.
  • Planting more trees.
  • Reducing, reusing and recycling resources.

VIII. Higher Order Thinking Questions

Samacheer Kalvi 8th Science Solutions Term 2 Chapter 3 Air

Question 1.
What will happen if oxygen has the capacity to burn itself?
Answer:
If oxygen has the capacity to bum itself, striking a match stick will be enough to bum all the oxygen in our planet’s atmosphere.

IX. Solve the crossword Puzzle by using the clues given below.

Question 1.
Across:
1. A gas that supports combustion.
4. The compound that turns lime water milky.
5. The Gaseous jacket that surrounds the Earth.
6. It is used as a refrigerant.
7. Solid form of carbon dioxide.
Down:
2. The process by which atmospheri&oitrogen is converted into nitrates.
3. The common name of the compound formed when nails are exposed to moist air.
8. It changes the fertility of the soil, destroys plants and aquatic life.
Answer:
Samacheer Kalvi 8th Science Solutions Term 2 Chapter 3 Air 6

Samacheer Kalvi 8th Science Solutions Term 2 Chapter 3 Air Read More »

Samacheer Kalvi 8th Science Solutions Term 2 Chapter 4 Atomic Structure

You can Download Samacheer Kalvi 8th Science Book Solutions Guide Pdf, Tamilnadu State Board help you to revise the complete Syllabus and score more marks in your examinations.

Tamilnadu Samacheer Kalvi 8th Science Solutions Term 2 Chapter 4 Atomic Structure

Samacheer Kalvi 8th Science Atomic Structure Text Book Exercises

I. Choose the best answer

Question 1.
The same proportion of carbon and oxygen in the carbon dioxide obtained from different sources proves the law of
(a) reciprocal proportion
(b) definite proportion
(c) multiple proportion
(d) conservation of mass
Answer:
(b) definite proportion

Samacheer Kalvi 8th Science Solutions Term 2 Chapter 4 Atomic Structure

Question 2.
Cathode rays are made up of –
(a) neutral particles
(b) positively charged particles
(c) negatively charged particles
(d) None of the above
Answer:
(c) negatively charged particles

Question 3.
In water, hydrogen and oxygen are combined in the ratio of by mass.
(a) 1 : 8
(b) 8 : 1
(c) 2 : 3
(d) 1 : 3
Answer:
(a) 1 : 8

Question 4.
Which of the following statements made by Dalton has not undergone any change?
(a) Atoms cannot be broken.
(b) Atoms combine in small, whole numbers to form compounds.
(c) Elements are made up of atoms.
(d) All atoms of an elements are alike
Answer:
(d) All atoms of an elements are alike

Question 5.
In all atoms of an element –
(a) the atomic and the mass number are same.
(b) the mass number is same and the atomic number is different.
(c) the atomic number is same and the mass number is different
(d) both atomic and mass numbers may vary.
Answer:
(a) the atomic and the mass number are same.

II. Fill in the blanks

  1. …………….. is the smallest particle of an element.
  2. An element is composed of …………….. atoms.
  3. An atom is made up of …………….., …………….. and ……………..
  4. A negatively charged ion is called …………….. while positively charged ion is called
  5. …………….. is a negatively charged particle (Electron/Proton).
  6. Proton is deflected towards the …………….. charged plate (positively, negatively).

Answer:

  1. Atom
  2. same kind of
  3. proton, electron, neutron
  4. anion, cation
  5. Electron
  6. negatively

III. Match the following

  1. Law of Conservation of Mass – Sir William Crookes
  2. Law of Constant Proportion – James Chadwick
  3. Cathode rays – Joseph Proust
  4. Anode rays – Lavoisier
  5. Neutrons – Goldstein

Answer:

  1. Law of Conservation of Mass – Lavoisier
  2. Law of Constant Proportion – Joseph Proust
  3. Cathode rays – Sir William Crookes
  4. Anode rays – Goldstein
  5. Neutrons – James Chadwick

IV. Answer briefly

Question 1.
State the Law of Conservation of Mass.
Answer:
The law states that during any chemical change, the total mass of the products is equal to the total mass of the reactants.

Samacheer Kalvi 8th Science Solutions Term 2 Chapter 4 Atomic Structure

Question 2.
State the Law of Constant Proportions.
Answer:
Law of constant proportions states that in a pure chemical compound the elements are always present in definite proportions by mass.

Question 3.
Write the properties of anode rays.
Answer:
Properties of Anode rays:

  1. Anode rays travel in straight lines.
  2. Anode rays are made up of material particles.
  3. Anode rays are deflected by electric and magnetic fields. Since, they are deflected towards the negatively charged plate, they consist of positively charged particles.

Question 4.
Define valency of an element with respect to hydrogen.
Answer:
Valency of an element is defined as the number of hydrogen atoms which combine with one atom of it.

Question 5.
Define the term ions or radicals.
Answer:
An atom or a group of atoms when they either lose or gain electrons, get converted into ions or radicals.

Question 6.
What is a chemical equation?
Answer:
A chemical equation is a short hand representation of a chemical reaction with the help of chemical symbols and formula.

Question 7.
Write the names of the following compounds.

  1. CO
  2. N2O
  3. NO2
  4. PCl5

Answer:

  1. Carbon monoxide.
  2. Nitrous oxide
  3. Nitrogen dioxide
  4. Phosphorous pentachloride

V. Answer the following

Question 1.
Find the valency of the element which is underlined in the following formula.

  1. NaCl
  2. CO2
  3. Al(PO2)
  4. Ba(NO3)2
  5. CaCl2

Answer:

  1. NaCl = 1
  2. CO2 = 4
  3. Al(PO4) = 3
  4. Ba(NO3)2 = 2
  5. CaCl2 = 2

Samacheer Kalvi 8th Science Solutions Term 2 Chapter 4 Atomic Structure

Question 2.
Write the chemical formula for the following compounds

  1. Aluminium sulphate
  2. Silver nitrate
  3. Magnesium oxide
  4. Barium chloride

Answer:

  1. Aluminium sulphate = Al2(SO4)3
  2. Silver nitrate = AgNO3
  3. Magnesium oxide = MgO
  4. Barium chloride = BaCl2

Question 3.
Write the skeleton equation for the following word equation and then balance them.

  1. Carbon + Oxygen → Carbon dioxide
  2. Phosphorus + Chlorine → Phosphorus pentachloride.
  3. Sulphur + Oxygen → Sulphur dioxide
  4. Magnesium + hydrogen chloride → Magnesium chloride + Hydrogen

Answer:
Balanced equation:

  1. C + O2 → CO2
  2. P4 + 10 Cl2 → 4PCl5
  3. S + O2 → SO2
  4. Mg + 2HCl → MgCl2 + H2

Skeleton equation:

  1. C + O2 → CO2
  2. P + Cl2 → PCl5
  3. S + O2 → SO2
  4. Mg + 2HCl → MgCl2 + H2

Question 4.
Balance the following chemical equation.

  1. Na + O2 → Na2O
  2. Ca + N2 → Ca3N2
  3. N2 + H2 → NH3
  4. CaCO3 + HCl → CaCl2 + CO2 + H2O
  5. Pb(NO3)2 → PbO + NO2 + O2

Answer:

  1. 4Na + O2 → 2Na2O
  2. 3Ca + N2 → Ca3N2
  3. N2 + 3H2 → 2NH3
  4. CaCO2 + 2HCl → CaCl2 + H2O + CO2
  5. 2Pb (NO3)2 → 2PbO + 4NO2 + O2

VI. Higher Order Thinking Questions

Question 1.
Why does a light paddle wheel placed in the path of cathode rays begin to rotate, when cathode rays fall on it?
Answer:
It is because the small particles of the cathode rays (electrons) have mass and energy. This energy is used in rotating the paddle wheels.

Samacheer Kalvi 8th Science Solutions Term 2 Chapter 4 Atomic Structure

Question 2.
How can we prove that the electrons carry negative charge?
Answer:
J.J. Thomson found that cathode rays were attracted by the positively charged plate and repelled by the negatively charged plate. This led him to the conclusion that the cathode rays (electrons) were made of negatively charged particles.

Question 3.
Ruthresh, Hari, Kanishka and Thahera collected different samples of water from a well, a pond, a river and underground water. All these samples were sent to a testing laboratory. The test result showed the ratio of hydrogen to oxygen as 1:8.

  1. What conclusion would you draw from the above experiment?
  2. Which law of chemical combination does it obey?

Answer:

  1. Water obtained from different sources like a well, a pond, a river and underground water will always consist of the same two elements hydrogen and oxygen in the ratio 1 : 8 by mass.
  2. It obeys the law of constant proportion.

Samacheer Kalvi 8th Science Atomic Structure Intext Activitics

Activity – 2

Question 1.
Classify the following ions into monovalent, divalent and trivalent.
Ni2+, Fe3+, Cu2+, Ba2+, Cs+, Zn2+, Cd2+, Hg2+, Pb2+, Mn2+, Fe2+, CO2+, Sr2+, Cr3+, Li+, Ca2+, Al3+
Answer:

  • Monovalent ions – Li+, Cs+
  • Divalent ions – Ni2+, Cu2+, Ba2+, Zn2+, Cd2+, Hg2+, Pb2+, Mn2+, Fe2+, CO2+, Ca2+, Sr2+
  • Trivalent ions – Fe3+, Cr3+, Al3+

Activity – 3

Question 1.
Write the chemical formula of the compounds
Samacheer Kalvi 8th Science Solutions Term 2 Chapter 4 Atomic Structure 1
Answer:
Samacheer Kalvi 8th Science Solutions Term 2 Chapter 4 Atomic Structure 2

Activity – 4

Question 1.
Write the names of the chemical compounds.
Samacheer Kalvi 8th Science Solutions Term 2 Chapter 4 Atomic Structure 3
Answer:
Samacheer Kalvi 8th Science Solutions Term 2 Chapter 4 Atomic Structure 4

Samacheer Kalvi 8th Science Atomic Structure Additional Questions

I. Choose the correct answer :

Question 1.
Which of the following scientists observed that cathode rays consists of negatively charged particles?
(a) John Dalton
(b) J.J. Thomson
(c) James Chadwick
(d) Democritus
Answer:
(b) J.J. Thomson

Samacheer Kalvi 8th Science Solutions Term 2 Chapter 4 Atomic Structure

Question 2.
The outer most shell of an atom is known as ………………..
(a) valency
(b) valence electron
(c) nucleus
(d) valance shell
Answer:
(d) valance shell

Question 3.
The valency of which of the element is zero.
(a) iron
(b) hydrogen
(c) helium
(d) oxygen
Answer:
(c) helium

Question 4.
The equation Na + H2O → NaOH + H2 is ………………
(a) correct
(b) iricorrect since it is not balanced
(c) incorrect since hydrogen should be written as H and not H2
(d) None
Answer:
(b) ipcorrect since it is not balanced

Question 5.
Whatis the valency of carbon?
(a) 1
(b) 2
(c) 3
(d) 4
Answer:
(d) 4

Question 6.
Metals form ……………..
(a) anions
(b) cations
(c) both a and b
(d) none
Answer:
(b) cations

Question 7.
Isotopes exist because atoms of the same element can have different numbers of –
(a) protons
(b) neutrons
(c) electrons
(d) none
Answer:
(b) neutrons

Samacheer Kalvi 8th Science Solutions Term 2 Chapter 4 Atomic Structure

Question 8.
An atom differs from its ion in ………………
Answer:
(a) nuclear charge
(b) mass number
(c) number of electrons
(d) number of protons
Answer:
(c) number of electrons

Question 9.
What is the atomic number of an element whose electronic configuration is 2, 8, 1?
(a) 10
(b) 23
(c) 11
(d) 8
Answer:
(c) 11

II. Fill in the Blanks

  1. Isotopes have the same ……………… number but different ……………… numbers.
  2. ……………… have the same mass number but different atomic numbers.
  3. Crookes Rays are also called as ……………….
  4. Cathode rays are made up of material particles which have mass and ……………….
  5. A proton can be defined as a ………………
  6. Atoms of all metals will have …………….. electrons in their outermost orbit.
  7. All non – metals will have ……………… electrons in the outermost orbit of their atoms.
  8. Atoms which carry positive or negative charges are called ……………….
  9. Maximum number of electrons that can be present in N shell is ……………….
  10. The atomic theory was first proposed by ……………….

Answer:

  1. atomic, mass
  2. Isobars
  3. Cathode rays
  4. kinetic energy
  5. hydrogen ion
  6. 1 to 3
  7. 4 to 7
  8. ions
  9. 32
  10. Dalton

III. True or False – if false give the correct statement

Question 1.
Anode rays travel in straight lines.
Answer:
True

Question 2.
James Chadwick discovered the fundamental particle called proton.
Answer:
False
Correct statement:
James Chadwick discovered the fundamental particle called neutron.

Samacheer Kalvi 8th Science Solutions Term 2 Chapter 4 Atomic Structure

Question 3.
Relative charge of an electron is – 1.
Answer:
True

Question 4.
Atoms of the same element are identical in all respects.
Answer:
True

Question 5.
The first scientific theory about atom was given by J J. Thomson.
Answer:
False
Correct statement:
The first scientific theory about atom was given by John Dalton.

Question 6.
In television tube, Cathode rays are deflected by magnetic fields.
Answer:
True

Question 7.
An atom has a number of orbits and each orbit has protons.
Answer:
False
Correct statement:
An atom has a number of orbits and each orbit has electrons.

Question 8.
The combining capacity of an atom is called valency.
Answer:
True

Samacheer Kalvi 8th Science Solutions Term 2 Chapter 4 Atomic Structure

Question 9.
Helium has two electrons in the outermost orbit and so it is chemically inert.
Answer:
True

Question 10.
When an atom gains an electron it has more number of electrons and thus it carries positive charge.
Answer:
False
Correct statement:
When an atom gains an electron it has more number of electrons and thus it carries negative charge.

IV. Match the following

Question 1.

1. J.J. Thomson (a) Law of definite proportions
2. Air (b) Law of indestructibility of mass
3. Hydrogen ion (c) Poor conductor of electricity
4. Law of constant proportions (d) Plum pudding model
5. Law of conservation of mass (e) H+

Answer:

  1. d
  2. c
  3. e
  4. a
  5. b

Samacheer Kalvi 8th Science Solutions Term 2 Chapter 4 Atomic Structure

Question 2.

1. Crooke’s tube (a) Negatively charged particles
2. Cathode rays (b) Cathode ray tube
3. Proton (c) Positively charged particles
4. Anode rays (d) 1.6 x 10-24 g

Answer:

  1. b
  2. a
  3. d
  4. c

V. Assertion and Reason.

Question 1.
Mark the correct choice as :
(a) If both assertion and reason are true and the reason is the correct explanation of the assertion.
(b) If both assertion and reason are true, but the reason is not the correct explanation of the assertion.
(c) If the assertion is true, but the reason is false.
(d) If the assertion is false, but the reason is true.

Question 1.
Assertion : Proton can be defined as a hydrogen ion (H+).
Reason : These protons are produced when one electron is removed from one hydrogen atom.
Answer:
(a) Both assertion and reason are true and the reason is the correct explanation of the assertion

Question 2.
Assertion : Helium has four electrons in the outermost orbit.
Reason : Neon has eight electron in the outermost orbit.
Answer:
(d) The assertion is false, but the reason is true

VI. Answer briefly

Question 1.
What is an atom?
Answer:
Atom is the smallest particle of matter that takes part in a chemical reaction.

Question 2.
What is electrical discharge?
Answer:
When electricity passes through air, remove the electrons*from the gaseous atoms and produces ions. This is called electrical discharge.

Samacheer Kalvi 8th Science Solutions Term 2 Chapter 4 Atomic Structure

Question 3.
What is the charge of a neutron?
Answer:
Neutron is a neutral particle, that is it carries no charge.

Question 4.
Define electronic configuration.
Answer:
The arrangement of electrons in the orbits is known as electronic configuration.

Question 5.
Define Orbits.
Answer:
Electrons revolve around the nucleus in a circular fixed paths is called orbits or shells.

Question 6.
Name the subatomic particles of an atom.
Answer:
Proton, electron and neutron.

Question 7.
Define nucleus.
Answer:
The nucleus is the central dense core of the atom consisting of neutrons and protons.

Question 8.
What is a reactant in a chemical equation?
Answer:
Reactant is the substance that take part in a chemical reaction.

Question 9.
What is a product in a chemical equation?
Answer:
Product is the substance that are formed in a chemical reaction.

Samacheer Kalvi 8th Science Solutions Term 2 Chapter 4 Atomic Structure

Question 10.
What are the two types of valency?
Answer:
Positive valency and negative valency.

Question 11.
Write any two advantages of Dalton’s atomic theory.
Answer:

  1. Dalton’s theory explains most of the properties of gases and liquids.
  2. This explains the law of chemical combination and the law of conservation of mass.

Question 12.
Write any two limitations of Dalton’s atomic theory.
Answer:

  1. Atom is no longer considered as the smallest indivisible particle.
  2. Substances made up of same kind of atoms may have different properties.

Question 13.
What are fluorescent materials?
Answer:
When invisible radiation falls on materials like zinc sulphite, they emit a visible light (or glow). These materials are called fluorescent.

Question 14.
Write the properties of neutrons.
Answer:

  1. Neutron is a neutral particle, that is, it carries no charge.
  2. It has mass equal to that of a proton that is 1.6 x 10-24 g.

Question 15.
An atom is electrically neutral. Give reason.
Answer:
The total number of protons present in an atom is equal to the total number of electrons, thus balancing the total charge of the atom.

Question 16.
What is atomic number?
Answer:
The total number of protons present in the nucleus of an atom is called its atomic number.

Question 17.
What is mass number?
Answer:
The total number of protons and neutrons present in the nucleus of an atom is called as mass number.

Question 18.
Mention any two information conveyed by a balanced chemical equation.
Answer:

  1. Balanced chemical equation gives us both qualitative and quantitative information.
  2. We can get quantitative information like the number of molecules/atoms of the reactants and products that is taking part in the reaction.

Question 19.
What is a balanced chemical equation?
Answer:
A balanced chemical equation is one in which the total number of atoms of any element on the reactant side is equal to die total number of atoms of that element on the product side.

Question 20.
Draw a diagram to show the electronic configuration of sodium atom.
Answer:
Samacheer Kalvi 8th Science Solutions Term 2 Chapter 4 Atomic Structure 5

Question 21.
Draw a diagram to show the electronic configuration of chlorine atom.
Answer:
Samacheer Kalvi 8th Science Solutions Term 2 Chapter 4 Atomic Structure 6

Question 22.
Name the four laws of chemical combinations.
Answer:

  1. Law of conservation of mass
  2. Law of constant proportion
  3. Law of multiple proportion
  4. Gay Lussac’s law of gaseous volumes.

Samacheer Kalvi 8th Science Solutions Term 2 Chapter 4 Atomic Structure

Question 23.
Write the names for the following compounds,

  1. Aluminium sulphate
  2. Silver nitrate.

Answer:

  1. Al2(SO4)3
  2. AgNO3

VII. Answer in detail

Question 1.

  1. Explain J.J. Thomson’s atom model with the help of a diagram.
  2. Write the limitations of Thomson’s Atom model.

Answer:
1. J.J. Thomson’s atom model with the help of a diagram:

  • Thomson proposed that the shape of an atom resembles a sphere having a radius of the order of 10-10m.
  • The positively charged particles are uniformly distributed with electrons arranged in such a manner that the atom is electrically neutral.
  • Thomson’s atom model was also called as the plum pudding model or the watermelon model.
  • The embedded electrons resembled the seed of watermelon while the watermelon’s red mass represented the positive charge distribution.
  • The plum pudding atomic theory assumed that the mass of an atom is uniformly distributed all over the atom.

Samacheer Kalvi 8th Science Solutions Term 2 Chapter 4 Atomic Structure 7

2. Limitations of Thomson’s Atom model:

  • Thomson’s model failed to explain how the positively charged sphere is shielded from the negatively charged electrons without getting neutralized.
  • This theory explains only about the protons and electrons and failed to explain the presence of neutral particle neutron.

Question 2.
Write a note on valency with respect to –

  1. Chlorine
  2. Oxygen.

Answer:
1. Valency with respect to Chlorine:

  • Since valency of chlorine is one, the number of chlorine atoms with which one atom of an element can combine is called valency.
  • In sodium chloride (NaCl) molecule, one chlorine atom combines with one sodium atom. So, the valency of sodium is one.
  • But, in magnesium chloride (MgCl2) valency of magnesium is two because it combines with two chlorine atoms.

2. Valency with respect to oxygen:

  • Valency can be defined as double the number of oxygen atoms with which one atom of an element can combine because valency of oxygen is two.
  • For example, in magnesium oxide (MgO) valency of magnesium is two.

Question 3.
Write the steps are followed to write down the chemical formula of a substance.
Answer:
Step 1:
Write down the symbols of elements/ions side by side so that the positive radical is on the left and the negative radical is on the right hand side.

Step 2:
Write the valencies of the two radicals above their symbols to the right in superscript (Signs ‘+’ and ‘-‘ of the ions are omitted).

Step 3:
Reduce the valencies to simplest ratio if needed. Otherwise interchange the valencies of the elements/ions. Write these numbers as subscripts. However, ‘1’ appearing on the superscript of the symbol is omitted.

Samacheer Kalvi 8th Science Solutions Term 2 Chapter 4 Atomic Structure

Question 4.
What are the steps involved in writing the skeletal equation?
Answer:
The following are the steps involved in writing the skeletal equation:

  1. Write the symbols and formula of each of the reactants on the left hand side (LHS) and join them by plus (+) sign.
  2. Follow them by an arrow (→) which is interpreted as gives or forms.
  3. Write on the right hand side (RHS) of arrow the symbols and formula for each of the products.
  4. The equation thus written is called as skeleton equation (unbalanced equation).
  5. If the product is a gas it should be represented by upward arrow (↑) and if it is a precipitate it should be represented by downward arrow (↓).
    Example: Mg + H2SO2 → MgSO4 + H2

Question 5.
What are the points to be followed while balancing a chemical equation?
Answer:
1. Initially the number of times an element occurs on both sides of the skeleton equation should be counted.

2. An element which occurs least number of times in reactant and product side must be balanced first. Then, elements occuring two times, elements occuring three times and so on in an increasing order must be balanced.

3. When two or more elements occur same number of times, the metallic element is balanced first in preference to non – metallic element. If more than one metal or nonmetal is present then a metal or non-metal with higher atomic mass (refer periodic table to find the atomic mass) is balanced first.

4. The number of molecules of reactants and products are written as coefficient.

5. The formula should not be changed to make the elements equal.

6. Fractional method of balancing must be employed only for molecule of an element (O2, H2,O3, P4,…) not for compound (H2O, NH3,…).

Samacheer Kalvi 8th Science Solutions Term 2 Chapter 4 Atomic Structure

Question 6.
What information are not conveyed by a balanced chemical equation?
Answer:

  1. Physical state of the reactants and the products.
  2. Heat changes (heat liberated or heat absorbed) accompanying the chemical reaction.
  3. Conditions such as temperature, pressure, catalyst etc., under which the reaction takes place.
  4. Concentration (dilute or concentrated) of the reactants and products.
  5. Speed of the reaction.

Question 7.
Explain the specific ways to be followed while naming chemical compounds?
Answer:
1. In naming a compound containing a metal and a non-metal, the name of the metal is written first and the name of the non-metal is written next after adding the suffix-ide to its name.
Examples:
NaCl – Sodium chloride
AgBr – Silver bromide

2. In naming a compound containing a metal, a non-metal and oxygen, name of the metal is written first and name of the non-metal with oxygen is written next after adding the suffix- ate (for more atoms of oxygen) or -ite (for less atoms of oxygen) to its name.
Examples:
Na2 SO4 – Sodium sulphate
Na 2 – Sodium nitrite

3. In naming a compound containing two non – metals only, the prefix mono, di, tri, tetra, penta etc. is written before the name of non – metals.
Examples:
SO2 – Sulphur dioxide
N2O5 – Dinitrogen pentoxide.

Question 8.
Derive the chemical formula for calcium chloride.
Answer:

  • Step 1 – Write the symbols of calcium and chlorine side by side. Ca Cl
  • Step 2 – Write the valencies of calcium and chlorine above their symbols to the right. Ca2 Cl1.
  • Step 3 – Interchange the valencies of elements. Ca Cl2.

Thus the chemical formula for calcium chloride is CaCl2.

Question 9.
Describe an experiment to prove that during a chemical charge, the total mass of matter remains the same.
Answer:
1. Prepare 5% of barium chloride (5g of BaCL in 100 ml of water) and sodium sulphatesolutions separately.

2. Take some solution of sodium sulphate in a conical flask and some solution of barium chloride in a test tube.

3. Hang the test tube in the conical flask.

Samacheer Kalvi 8th Science Solutions Term 2 Chapter 4 Atomic Structure 8

4. Weigh the flask with its contents. Now mix the two solutions by tilting and swirling the flask. Weigh the flask after the chemical reaction is occurred.

5. Record your observation. It can be seen that the weight of the flask and the contents remains the same before and after the chemical change.

6. Hence, it is proved that during a chemical change, the total mass of matter remains the same.

Question 10.
Explain the advantages and limitations of Dalton’s atomic theory.
Answer:
Advantages of Dalton’s Atomic Theory:

  1. Dalton’s theory explains most of the properties of gases and liquids.
  2. This explains the laws of chemical combination and the law of conservation of mass.
  3. This theory helps to recognize the molecular differences of elements and compounds.

Limitations of Dalton’s Atomic Theory:

  1. Atom is no longer considered as the smallest indivisible particle.
  2. Atoms of the same element have different masses (Isotopes).
  3. Atoms of the different elements may have same masses (Isobars).
  4. Substances made up of same kind of atoms may have different properties
  5. Example: Coal, Graphite and Diamond are made up of carbon atoms but they differ in their properties

Question 11.
Explain the construction of cathode Ray Tube (CRT) with a diagram.
Answer:

  1. Cathode Ray Tube is a long glass tube filled with gas and sealed at both the ends.
  2. It consists of two metal plates (which act as electrodes) connected with high voltage.
  3. The electrode which is connected to the negative terminal of the battery is. called the cathode (negative electrode).
  4. The electrode connected to the positive terminal is called the anode(positive electrode).
  5. There is a side tube which is connected to a pump.
  6. The pump is used to lower the pressure inside the discharge tube.

Samacheer Kalvi 8th Science Solutions Term 2 Chapter 4 Atomic Structure 9

Question 12.
Explain the properties of Cathode rays.
Answer:
Properties of Cathode rays:

  1. Cathode rays travel in straight line from cathode towards anode.
  2. Cathode rays are made up of material particles which have mass and kinetic energy.
  3. Cathode rays are deflected by both electric and magnetic fields. They are negatively charged particles.
  4. The nature of the cathode rays does not depend on the nature of the gas filled inside the tube or the cathode used.

Samacheer Kalvi 8th Science Solutions Term 2 Chapter 4 Atomic Structure

Question 13.
Write the main postulates of Dalton’s Atomic theory.
Answer:
The nain postulates of Dalton’s atomic theory are:

  1. All the matters are made up of extremely small particles called atoms (Greek philosopher Democritus used the same name for the smallest indivisible particles).
  2. Atoms of the same element are identical in all respects (size, shape, mass and properties).
  3. Atoms of different elements have different sizes and masses and possess different properties.
  4. Atoms can neither be created nor be destroyed, i.e., atom is indestructible.
  5. Atoms of different elements may combine with each other in a fixed simple ratio to form molecules or compounds.
  6. An atom is the smallest particle of matter that takes part in a chemical reaction.

Question 14.
Complete the table:
Samacheer Kalvi 8th Science Solutions Term 2 Chapter 4 Atomic Structure 10
Answer:

  1. Oxide
  2. 2
  3. OH
  4. H2CO3

VIII. Solve the following crossword puzzle with the help of the given clues.

Question 1.
Across:
1. The particles that build up an atom.
3. The arrangement of electrons in a succession of energy levels or shells.
5. An electrically neutral sub atomic particle that is part of the nucleus of an atom.
6. A whole number that represents the ability of an atom or a group of atoms to combine with other atoms or group of atoms.
7. The number of protons in the nucleus of an atom.
8. The smallest unit of an element that maintains the properties of an element.
A sub – atomic particle that has a positive electric charge.
Down:
2. A substance that cannot be broken down into simpler substance by chemical means.
4. The total number of protons and neutrons present in the nucleus of an atom.
9. An ion that has a negative charge.
11 A sub – atomic particle with a negative electric charge.
12. Positively charged ions.
Answer:
Samacheer Kalvi 8th Science Solutions Term 2 Chapter 4 Atomic Structure 11

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Samacheer Kalvi 8th Social Science Civics Solutions Term 1 Chapter 2 Citizen and Citizenship

You can Download Samacheer Kalvi 8th Social Science Book Solutions Guide Pdf, Tamilnadu State Board help you to revise the complete Syllabus and score more marks in your examinations.

Tamilnadu Samacheer Kalvi 8th Social Science Civics Solutions Term 1 Chapter 2 Citizen and Citizenship

Samacheer Kalvi 8th Social Science Citizen and Citizenship

I. Choose the correct answer

Question 1.
Which of the following is not a condition for becoming the citizen of India?
(a) Birth
(b) Acquiring property
(c) Descent
(d) Naturalization
Answer:
(b) acquiring property

Question 2.
……………. of the Constitution of India deals with the Citizenship.
(a) Part II
(b) Part II Article 5 – 11
(c) Part II Article 5 – 6
(d) Part I Article 5 – 11
Answer:
(b) Part II Article 5 – 11

Samacheer Kalvi 8th Social Science Civics Solutions Term 1 Chapter 2 Citizen and Citizenship

Question 3.
Who is called the first citizen of India?
(a) The Prime Minister
(b) The President
(c) The Chief Minister
(d) The Chief Justice of India
Answer:
(b) The President

II. Fill in the Blanks

  1. …………….. of a state enjoy full civil and political rights.
  2. Our Indian Constitution provides for only ……………… citizenship.
  3. An Indian citizen who is residing outside India and holds an Indian passport are called ……………..
  4. All have right and ……………. responsibility citizens.
  5. ……………. is an idea enabling young people to access and participate in shaping modem society.

Answer:

  1. Citizens
  2. Single
  3. Non – Resident Indian
  4. Civic
  5. Global citizenship

III. State true or false

Question 1.
USA has single citizenship.
Answer:
False
Correct statement:
USA has dual citizenship.

Question 2.
OCI card holder has voting rights in India.
Answer:
False
Correct statement:
OCI card holder has no voting rights in India.

Question 3.
Citizen of India can enjoy Fundamental Rights guaranteed by our constitution.
Answer:
True

Samacheer Kalvi 8th Social Science Civics Solutions Term 1 Chapter 2 Citizen and Citizenship

Question 4.
Nationality can be change and citizenship can not be changed.
Answer:
False
Correct statement:
Nationality cannot be change and citizenship can be changed

IV. Consider the following statements. Tick (V) the appropriate answer

Question 1.
Indian Citizen of a person can be terminated if
I. a person voluntarily acquires the citizenship of some other country.
II. a person who has become a citizen through registration.
III. the Government of India is satisfied that citizenship was obtained by fraud.
IV. a citizen who is by birth indulges in trade with an enemy country during war.

(a) I and II are correct.
(b) I and III are correct
(c) I, III, IV are correct.
(d) I, II, III are correct.
Answer:
(b) I and III are correct

Question 2.
Assertion – When Pondicherry becomes the part of India in 1962, the people lived there became Indian citizens.
Reason – It was done by one of the provisions of the Act of 1955 – by incorporation of Territory.

(a) R is the correct explanation of A
(b) R is not the correct explanation of A
(c) A is wrong but R is correct.
(d) Both A and R are wrong.
Answer:
(a) R is the correct explanation of A

V. Answer the following in one or two sentences

Question 1.
Name the types of citizens?
Answer:
There are two types of citizens

  • Natural Citizens
  • Naturalised Citizens

Question 2.
What are the Rights that a citizen can enjoy in our country?
Answer:

  1. Fundamental Rights
  2. Right to vote in the election to the Lok Sabha and the State Legislature
  3. Right to hold certain public offices
  4. Right to become the Member of Parliament and State Legislature.

Samacheer Kalvi 8th Social Science Civics Solutions Term 1 Chapter 2 Citizen and Citizenship

Question 3.
Mention any three qualities of a good citizen.
Answer:

  1. Loyalty to the Constitution
  2. Obey laws.
  3. Respecting diversity

Question 4.
Name the five ways of acquiring citizenship.
Answer:

  1. By Birth
  2. By Descent
  3. By Registration
  4. By Naturalisation
  5. By incorporation of Territory

Question 5.
What do you know about the citizenship Act of 1955?
Answer:
Indian Citizenship Act of 1955 prescribes the five ways of acquisition of Indian Citizenship. They are by birth, descent, registration, naturalisation, and incorporation of territory.

VI. Answer the following

Question 1.
On what grounds that the citizenship of a person is cancelled?
Answer:
Part II of the Constitution of India (Article 5-11) prescribes three ways of losing Citizenship

  • Renunciation
  • Termination
  • Deprivation

Renunciation: It is a voluntary act when a person after acquiring the Citizenship of another country gives up his/her Indian citizenship.

Termination: When an Indian citizen voluntarily acquires the citizenship of another country, he/she automatically ceases to be an Indian Citizen. It takes place by the operation of law.

Deprivation: It is a compulsory termination that the Citizenship is deprived on the basis of an order of the Government of India in cases involving the acquisition of Indian citizenship by fraud, false representation, or being disloyal to the Constitution.

VII. Student Activity

Question a.
Tabulate: How will you be a good citizen inside the classroom and outside the classroom.
Answer:
(a) Inside the class room:

  • I will be respectful to others
  • I will value and protect school property
  • will follow school rules.
  • Display good character by being honest and responsible.

(b) Outside the class room:

  • I will take responsibility for what goes on in my community.
  • I will do my part for the common good
  • I will participate in community service.
  • I will help to take care of the environment.
  • Will obey the law.

Samacheer Kalvi 8th Social Science Civics Solutions Term 1 Chapter 2 Citizen and Citizenship

Question b.
My responsibility as a Good Citizen (write any three points)

  1. At Home
  2. At School
  3. To myself
  4. To the Environment

Answer:
At Home:

  • Being responsible
  • Using magic words and caring deeds
  • Being helpful

At School:

  • Being respectful
  • Follow rules
  • Being patriotic

To myself:

  • Being honest
  • Being self-disciplined
  • Displaying good character

To the Environment:

  • Being compassionate
  • Socially responsible

Samacheer Kalvi 8th Social Science Civics Citizen and Citizenship Additional Questions

I. Choose the correct answer

Question 1.
A person born in India on or after 26th January 1950 but before 1 July 1987 is an Indian citizen by ……………..
(a) Birth
(b) Descent
(c) Registration
(d) Natrualation
Answer:
(a) Birth

Question 2.
A citizen of any country, who renounces the citizenship of that country, becomes an Indian citizen by …………….
(a) Descent
(b) Naturalisation
(c) Registration
(d) Incorporation of territory
Answer:
(b) Naturalisation

Question 3.
According to ……………. amendment of our constitution a set of Fundamental duties are prescribed.
(a) 55
(b) 51
(c) 42
(d) 32
Answer:
(c) 42

Samacheer Kalvi 8th Social Science Civics Solutions Term 1 Chapter 2 Citizen and Citizenship

Question 4.
Pravasi Bharatiya Divas is celebrated once in ……………. years.
(a) 4
(b) 3
(c) 5
(d) 2
Answer:
(d) 2

II. Fill in the blanks

  1. …………….. is the study of the Government.
  2. …………….. is sponsored by Ministry of External Affairs of Government of India.
  3. …………….. and ……………. are two terms that refer to non-nationals of a country.

Answer:

  1. Civics
  2. Pravasi Bharatiya Divas
  3. Alien, Immigrant

III. State True or False

Question 1.
A person bom outside India on or after 10th December 1992 is a citizen of India if either of his parents is an Indian citizen at the time of his birth.
Answer:
True

Question 2.
As per the order precedence, Prime Minister is the first citizen of India.
Answer:
False
Correct statement:
As per the order precedence, President is the first citizen of India.

IV. Consider the following statements. Tick (V) the appropriate answer:

Question 1.
A person acquires citizenship by Registration, if
(i) He is of Indian Origin who is ordinarily resident in any country or place outside India.
(ii) He is of Indian Origin who is ordinarily resident in India for five years before applying for registration.
(iii) He marries a citizen of India and is ordinarily resident in India for seven years before applying for registration.

(a) i and ii are correct
(b) ii and iii are correct
(c) i is correct (d) i and iii are correct
Answer:
(d) i and iii are correct

V. Answer in brief

Question 1.
Who is a citizen of a country?
Answer:
Citizen is a person of a country who is entitled to enjoy all the legal rights and privileges granted by a state and is obligated to obey its laws and to fulfill his duties.

Question 2.
Define Citizenship.
Answer:
Citizenship is the status given to the citizens which provides them the right to legally live in a country as long as they want.

Question 3.
Mention one criterion under which a person becomes a citizen of India by Naturalisation.
Answer:
If he is not a citizen of any country where citizens of India are Prevented from becoming subjects or citizens of that country.

Samacheer Kalvi 8th Social Science Civics Solutions Term 1 Chapter 2 Citizen and Citizenship

Question 4.
Define Nationality.
Answer:
Nationality is the status of belonging to a particular nation by origin, birth basically, it’s an ethnic and racial concept. Nationality of a person cannot be changed.

Question 5.
When is citizenship granted to an individual by the Government?
Answer:
Citizenship is granted to an individual by the government of the country when he/ she complies with the legal formalities. Citizenship can be changed.

Question 6.
What does the term ‘Alien’ refer to?
Answer:
Alien refers to all non-citizens or non – nationals residing in a country.eg. tourists, foreign students.

Question 7.
What do you mean by ‘Immigrant’?
Answer:
Immigrant refers to alien who has been granted the right to reside and work permanently without restriction in a particular country.

Question 8.
What is Global citizenship?
Answer:
Global citizenship is an idea that everyone, no matter where they live is part of a worldwide community rather than as the citizen of particular nation or place. Enabling young people to access and participate in shaping modem society.

Samacheer Kalvi 8th Social Science Civics Solutions Term 1 Chapter 2 Citizen and Citizenship

Question 9.
Write a note on Overseas Indians’ day.
Answer:
Pravasi Bharatiya Divas (PBD) Sponsored by the Ministry of External Affairs of Government of India is celebrated once in every two years, to “mark the contributions of Overseas Indian Community in the development of India”. The day commemorates the arrival of Mahatma Gandhi in India from South Africa.

VI. Answer the following in Detail

Question 1.
Write a note on the Overseas citizenship of India.
Answer:
1. Non – Resident Indian:
An Indian citizen who is residing outside India and holds an Indian passport.

2. Person on Indian Origin:
A person whose any ancestors was an Indian nationals and who is presently holding another country’s citizenship.(other than Pakistan, Bangaladesh, Sri Lanka, Bhutan,Afghanistan. China and Nepal). The PIO scheme was rescinded w.e.f. 09-01-2015

3. Overseas Citizen of India Card Holder:
It is an immigration status permitting a foreign citizen of Indian origin to live and work in the Republic of India indefinitely. (Except the citizen of Pakistan and Bangladesh). There are no voting rights for an OCI card holder.

Samacheer Kalvi 8th Social Science Civics Solutions Term 1 Chapter 2 Citizen and Citizenship Read More »

Samacheer Kalvi 8th Social Science Geography Solutions Term 2 Chapter 2 Hazards

You can Download Samacheer Kalvi 8th Social Science Book Solutions Guide Pdf, Tamilnadu State Board help you to revise the complete Syllabus and score more marks in your examinations.

Tamilnadu Samacheer Kalvi 8th Social Science Geography Solutions Term 2 Chapter 2 Hazards

Samacheer Kalvi 8th Social Science Geography Hazards Textbook Evaluation

I. Choose the correct answer

Question 1.
……………. percentage of nitrogen is present in the air.
(a) 78.09%
(b) 74.08%
(c) 80.07%
(d) 76.63%
Answer:
(a) 78.09%

Samacheer Kalvi 8th Social Science Geography Solutions Term 2 Chapter 2 Hazards

Question 2.
Tsunami in Indian Ocean took place in the s ear …………….
(a) 1990
(b) 2004
(c) 2005
(d) 2008
Answer:
(b) 2004

Question 3.
The word tsunami is derived from ……………. language.
(a) Hindi
(b) French
(c) Japanese
(d) German
Answer:
(c) Japanese

Question 4.
The example of surface water is –
(a) Artesian well
(b) Groundwater
(c) Subsurface water
(d) Lake
Answer:
(d) Lake

Question 5.
Event that occurs due to the failure of monsoons.
(a) Condensation
(b) Drought
(c) Evaporation
(d) Precipitation
Answer:
(b) Drought

II. Fill in the blanks

  1. Hazards may lead to ……………..
  2. Landslide is an example of …………….. hazard.
  3. On the basis of origin, hazard can be grouped into …………….. categories.
  4. Terrorism is an example of …………….. hazard.
  5. Oxides of Nitrogen are …………….. pollutants which affects the human beings.
  6. Chernobyl nuclear accident took place in ……………..

Answer:

  1. disaster
  2. Geologic (or) Seismic
  3. Eight
  4. Human – induced
  5. Primary
  6. 26th April 1986

III. Match the following

Samacheer Kalvi 8th Social Science Geography Solutions Term 2 Chapter 2 Hazards 1
Answer:
Samacheer Kalvi 8th Social Science Geography Solutions Term 2 Chapter 2 Hazards 2

IV Answer in brief

Question 1.
Define‘hazard’.
Answer:
Hazards are defined as a thing, person, event, or factor that poses a threat to people, structures, or economic assets and which may cause a disaster.

Question 2.
What are the major types of hazards?
Answer:

  1. Atmospheric hazard
  2. Geologic 7 Seismic hazard
  3. Hydrologic hazard
  4. Volcanic hazard
  5. Environmental hazard
  6. Biological hazard
  7. Human – induced hazard
  8. Technological hazard

Samacheer Kalvi 8th Social Science Geography Solutions Term 2 Chapter 2 Hazards

Question 3.
Write a brief note on hazardous wastes.
Answer:
The wastes that may or tend to cause adverse health effects on the ecosystem and human beings are called hazardous wastes.

Question 4.
List out the major flood prone areas of our country.
Answer:

  1. The major flood prone areas in north and northeast India are, Punjab, Haryana, Uttar Pradesh, North Bihar, West Bengal and Brahmaputra valley.
  2. Coastal Andhra Pradesh, Odisha and Southern Gujarat are the other regions which are also prone to flood often.

Question 5.
Mention the types of drought.
Answer:
The drought is classified into three major types

  • Meteorological drought
  • Hydrological drought
  • Agricultural drought

Question 6.
Why should not we construct houses at foothill areas?
Answer:
We should not construct houses at foothill areas because it has rapid downward movement of rocks and soil and vegetation down the slope under the influence of gravity which leads to landslides.

V. Distinguish the following :

Question 1.
Hazards and disasters.
Answer:
1. Hazard:
A natural hazard is a natural process and event that is a potential threat to human life and property.

2. Disasters:
A disaster is a hazardous event that occurs over a limited time span in a defined area and causes great damage to property / loss of life, also needs assistance from others.

Question 2.
Natural hazard and human-made hazard.
Answer:
Natural Hazards:

  1. These are the results of natural processes and man has no role to play in such hazards.
  2. For example: Earthquakes, Floods, Cyclonic storms and volcanic eruption etc.

Human – made – Hazards:

  1. These are caused by undesirable activities of human. It can be the result of an accident such as an industrial chemical leak or oil spill.
  2. For example: Hazardous wastes, pollution of air, water and land etc.

Samacheer Kalvi 8th Social Science Geography Solutions Term 2 Chapter 2 Hazards

Question 3.
Flood and drought.
Answer:
Flood:

  1. Flood is an event in which a part of the earth’s surface gets inundated.
  2. Heavy rainfall and large waves in seas are the common causes of flood.

Drought:

  1. Any lack of water to satisfy the normal needs of agriculture, livestock, industry or human population may be termed as a drought.
  2. Droughts in India occur in the event of a failure of monsoon.

Question 4.
Earthquake and tsunami.
Answer:
1. Earthquake:
Earthquake is a violent tremor in the earth’s crust, sending out a series of stock waves in all directions from its place of origin.

2. Tsunami:
Tsunami refers to huge ocean waves caused by an earthquake, landslide or volcanic eruption. It is generally noticed in the coastal regions and travel between 640 and 960 Km/h.

VI. Answer in a paragraph

Question 1.
Write an essay on air pollution.
Answer:

  • Air is a mixture of several gases.
  • The main gases are Nitrogen (78.09%) for forming products such as fertilizers for plants and for making the air inert, Oxygen (20.95%) for breathing, and Carbon dioxide (0.03%) for Photosynthesis.
  • Air pollution is the contamination of the indoor or outdoor air by a range of gases and solids that modify its natural characteristics and percentage.
  •  It categorized into
    • Primary pollutants
    • Secondary pollutant.

Primary Pollutants:

  • Oxides of Sulphur
  • Oxides of Nitrogen
  • Oxides of Carbon
  • Particulate Matter
  • Other Primary Pollutants

Secondary Pollutants:

  • Ground-Level Ozone
  • Smog

Question 2.
Define earthquake and list out its effects.
Answer:
Earthquakes:
Earthquake is a violent tremor in the earth’s crust, sending out a series of shock waves in all directions from its place of origin.

Effects of Earthquakes:

  1. The Primary effects of earthquakes are ground shaking, ground rupture, landslides, Tsunamis and soil liquefaction.
  2. The Secondary effects of earthquakes are fires.
  3. The effects of earthquakes are terrible and devasting. Thus leads to distraction of buildings, loss of money, property and lines of people. This affects the mental and emotional health of people.

Question 3.
Give a detailed explanation on the causes of landslides.
Answer:

  • Landslide is a rapid downward movement of rock, soil, and vegetation down the slope under the influence of gravity. Landslides are generally sudden and infrequent.
  • The presence of steep slopes and heavy rainfall are the major causes of landslides.
  • Weak ground structure, deforestation, earthquakes, volcanic eruptions, mining, construction of roads and railways over the mountains are the other causes of landslides.
  • In Tamil Nadu, Kodaikanal and Ooty are frequently affected by landslides.

Samacheer Kalvi 8th Social Science Geography Solutions Term 2 Chapter 2 Hazards

Question 4.
Elaborately discuss the effects water pollution.
Answer:
Water Pollution:

  1. Water pollution may be defined as alteration in the physical, chemical and biological characteristics of water which may cause harmful effects in human and aquatic life.
  2. In India, water pollution has been taking place on a large scale.
  3. Some of these waterborne diseases are Typhoid, Cholera, Paratyphoid fever, Dysentery, Jaundice and Malaria.
  4. Chemicals in the water also have negative effects on our health.
  5. Pesticides – can damage the nervous system and cause cancer because of the Carbonates and organophosphere that they may contain.
  6. Both surface and groundwater bodies are polluted to a great extent.

VII. Activities

Question 1.
Name the hazards which you have identified.
Samacheer Kalvi 8th Social Science Geography Solutions Term 2 Chapter 2 Hazards 3
Answer:
Activity to be done by the students.

Question 2.
List out the hazards that occur frequently and occasionally in your place.
Samacheer Kalvi 8th Social Science Geography Solutions Term 2 Chapter 2 Hazards 4
Answer:
Activity to be done by the students.

Question 3.
On the map of Tamilnadu shade the 13 coastal districts in different colors.
Answer:
Samacheer Kalvi 8th Social Science Geography Solutions Term 2 Chapter 2 Hazards 5

Samacheer Kalvi 8th Social Science Geography Hazards Additional Questions

I. Choose the correct answer

Question 1.
…………. is an example of human induced pollutants hazard.
(a) Terrorism
(b) Evaporation
(c) Nuclear accident
(d) None of these
Answer:
(a) Terrorism

Samacheer Kalvi 8th Social Science Geography Solutions Term 2 Chapter 2 Hazards

Question 2.
…………. in Indian ocean took place in the year 2004.
(a) Earthquake
(b) Droughts
(c) Landslide
(d) Tsunami
Answer:
(d) Tsunami

Question 3.
A …………. hazard ¡s a natural process.
(a) Socio natural hazard
(b) Human – made
(c) Natural
(d) All the bove
Answer:
(C) Naturall

Question 4.
…………. can be broadly classified Into three types.
(a) Economics
(b) Hazards
(c) Environment
(d) None of these
Answer:
(b) Hazards

Question 5.
The main examples of natural hazards are ………….
(a) earthquakes
(b) floods
(c) cyclonic
(d) all of these
Answer:
(d) all of these

Question 6.
…………. hazards are caused by undesirable activities of human.
(a) Human – made
(b) Natural
(c) Socio – natural
(d) Atmospheric
Answer:
(a) Human – made

Question 7.
…………. are caused by natural forces in mountainous areas.
(a) Over populations
(b) Landslides
(c) Socio – natural
(d) Hydrologic hazard
Answer:
(b) Landslides

Question 8.
…………. Is a serious problem In most big Urban.
(a) Storm
(b) Landslides
(c) Smog
(d) Droughts
Answer:
(c) Smog

Question 9.
…………. surge hazards may be worsened by the destruction of mangroves.
(a) Storm
(b) Smog
(c) Flood
(d) Droughts
Answer:
(a) Stormi

Samacheer Kalvi 8th Social Science Geography Solutions Term 2 Chapter 2 Hazards

Question 10.
Heavy rainfall and large waves In seas are the common causes of …………..
(a) Droughts
(b) Smog
(c) Tsunami
(d) Flood
Answer:
(d) Flood

Question 11.
…………. storm is a strong wind circulating around a low pressure area in the atmosphere.
(a) Tropical cyclone
(b) Cyclonic
(c) Heavy
(d) None of these
Answer:
(b) Cyclonic

Question 12.
The west coast of India is …………. vulnerable to storm surges than the east coast.
(a) less
(b) more
(c) great
(d) high
Answer:
(a) less

Question 13.
…………. drought is a reduction in rainfall for a specific period below a specific level.
(a) Agricultural
(b) Hydro – logical
(c) Landslides
(d) Meteorological
Answer:
(d) Meteorological

Question 14.
…………. droughts associated with reduction of water in streams, rivers and reservoirs.
(a) Hydro – logical
(b) Agricultural
(c) Meteorological
(d) Both ‘b’ and ‘c’
Answer:
(a) Hydro – logical

Question 15.
…………. droughts refers to the condition in which the agricultural crops get affected due to lack of rainfall.
(a) Meteorological
(b) Agricultural
(c) Hydro – logical
(d) Both ‘a’ and ‘b’
Answer:
(b) Agricultural

Question 16.
…………. in India occur in the event of a failure of monsoon.
(a) Floods
(b) Landslides
(c) Droughts
(d) Earthquakes
Answer:
(c) Droughts

Question 17.
The dry region lying in the leeward side of the …………..
(a) Western Ghats
(b) Eastern Ghats
(c) Both ‘a’ and ‘b’
(d) None of these
Answer:
(a) Western Ghats

Samacheer Kalvi 8th Social Science Geography Solutions Term 2 Chapter 2 Hazards

Question 18.
…………. is a rapid downward movement of rock, soil and vegetation down the slope under the influence of gravity.
(a) Drought
(b) Flood
(c) Landslide
(d) Earthquake
Answer:
(c) Landslide

Question 19.
…………. is a mixture of several gases.
(a) Water
(b) Air
(c) Soil
(d) All of these
Answer:
(b) Air

Question 20.
…………. pollutant is an air pollutant emitted directly from a source.
(a) Primary
(b) Secondary
(c) Tertiary
(d) All of these.
Answer:
(a) Primary

II. Fill in the blanks:

  1. Hazards can be broadly classified into …………. types
  2. Smog is a serious problem in most …………. areas.
  3. The beginning of …………. century, the earth supported a human population.
  4. The meaning of old french “Hazards” ………….
  5. A catastrophe was recover …………. time.
  6. …………. can disturb the safety health, welfare of people.
  7. …………. is a violent tremor in the earth’s crust.
  8. …………. percentage of carbon di oxide present in the air.
  9. …………. percentage of oxygen present in the air.
  10. …………. nuclear accident took place in 26th April 1986.
  11. …………. hazards are caused by the combined effect forces and misdeeds of human.
  12. Storm surge hazards may be worsened by the destruction of …………..
  13. A sudden rise of seawater due to tropical cyclone is called ……………
  14. In Tamil Nadu coast …………… and …………… districts are frequently affected.
  15. The drought could be classified into …………… major types.
  16. Presence of steep slope and heavy rainfall are the major causes of …………….
  17. The word ‘tsu’ meaning ……………..
  18. The word ‘nami’ meaning ……………..
  19. The atomic bomb dropped on Hiroshima (Japan) in ………………
  20. ……………… the wastes resulting from ordnance manufacturing and some industrial gases.
  21. ……………… refers to huge ocean waves caused by an earthquake, landslide (or) volcanic eruption.

Answer:

  1. Three
  2. big urban
  3. Twenty first
  4. a game of dice
  5. long
  6. Hazards
  7. Earthquake
  8. 0.03%
  9. 20.95%
  10. Chernobyl
  11. Socio – natural
  12. mangroves
  13. storm surge
  14. Cuddalore, Nagapattinam
  15. three
  16. Landslides
  17. harbour
  18. ‘wave’
  19. 1945
  20. Explosives
  21. Tsunami

III. Match the following

Samacheer Kalvi 8th Social Science Geography Solutions Term 2 Chapter 2 Hazards 6
Answer:

  1. c
  2. e
  3. d
  4. b
  5. a

Samacheer Kalvi 8th Social Science Geography Solutions Term 2 Chapter 2 Hazards 7
Answer:

  1. e
  2. d
  3. b
  4. c
  5. a

IV. State True or False

  1. Hazards are classified into natural, human – made and socio – natural hazards
  2. Earthquake is a violent tremor in the earth’s crust, sending out a series of shock waves in all directions from its place of origin.
  3. Heavy rainfall and large waves in seas are not the common causes of flood.
  4. The West coast of India is more vulnerable to storm surge than the east coast.
  5. The coastal belt around the Gulf of Kutch.
  6. The droughts could be classified into six types.
  7. Hydro – logical droughts is associated with reduction of water in streams, rivers and reservoirs.
  8. Agricultural drought refers to the condition in which the agricultural crops get affected due to more of rainfall.
  9. Weak ground structure, mining, construction of roads and railways over the mountains are the causes of landslides.
  10. The word ‘Tsunami’ is derived from latin world ‘tsu’ meaning harbour.

Answer:

  1. True
  2. True
  3. False
  4. False
  5. True
  6. False
  7. True
  8. False
  9. True
  10. False

V. Consider the following statements and Tick (✓) the appropriate answer

Samacheer Kalvi 8th Social Science Geography Solutions Term 2 Chapter 2 Hazards

Question 1.
Which of the following statements are correct:
(i) Oxides of Nitrogen are primary pollutants which affects the human beings.
(ii) On the basis of origin, hazard can be grouped into eight categories.
(iii) Delayed actions may increase the economic losses.
(iv) The major causes of water pollution in India are sewages and soil wastes,

(a) (i) & (ii) are Correct
(b) (i), (ii) & (iii) are Correct
(c) (i), (ii) and (iv) are Correct
(d) (i), (ii), (iii) and (iv) are Correct
Answer:
(d) (i), (ii), (iii) and (iv) are Correct

Question 2.
Consider the following statements and tick the appropriate answer
Statement (A) : Water pollution may be defined as alteration in which the physical, chemical and biological characteristics of water.
Reason (R) : Water pollution cause harmful effects in human and aquatic life.
(a) A is correct and R is the correct explanation of A
(b) A is correct but R is not correct explanation of A
(c) Both A and R are correct
(d) Both A and Rare wrong
Answer:
(a) A is correct and R is the correct explanation of A

Question 3.
Which one of rthe following is correctly matched?
(a) Secondary Pollutant – Smog
(b)Primary Pollutant – Ground Level Ozone
(c) Water Pollution – Earthquake
(d) 2016 – Tsunami in India
Answer:
(a) Secondary Pollutant – Smog

Question 4.
Which one of the following is not correctly matched?
(a) Ecosystem – Hazardous waste
(b) Chemic1als – Explosives
(c) Carbon di oxide – 0.05%
(d) Oxygen – 20.95%
Answer:
(C) Carbon di oxide – 0.05%

VI. Answer the following one or two sentences

Question 1.
List out any four major causes of water pollution in India.
Answer:

  1. Urbanization
  2. Industrial effluents
  3. Se-wages
  4. Solid wastes

Question 2.
Define prevention.
Answer:
Prevention is defined as the activities taken to prevent a natural calamity or potential hazard from having harmful effects on either people or economic assets.

Samacheer Kalvi 8th Social Science Geography Solutions Term 2 Chapter 2 Hazards

Question 3.
Define Water Pollution.
Answer:
Water Pollution may be defined as alteration in the physical, chemical and biological characteristics of water, which may cause harmful effects in human and aquatic life.

Question 4.
List out any four major hazardous wastes.
Answer:

  1. Chemicals
  2. Biomedical wastes
  3. Flammable wastes
  4. Explosives

Question 5.
What do you mean by Tsunami?
Answer:

  1. Tsunami refers to huge ocean waves caused by an earthquake, landslide or volcanic eruption.
  2. It is generally noticed in the coastal regions and travel between 640 and 960 Km/h.

Question 6.
List out the major drought prone areas of our country.
Answer:

  1. The arid and semi arid region from Ahmadabad to Kanpur on one side and from Kanpur to Jalandhar on the other.
  2. The dry region lying in the leeward side of the Western Ghats.

Question 7.
What is earthquake?
Answer:
Earthquake is a violent tremor in the earth’s crust, sending out a series of shock waves in all directions from its place of origin.

Question 8.
List out the Atmospheric hazards.
Answer:
Tropical storms, Thunderstorms, Lightning, Tornadoes, Avalanches, Heat waves, fog and forest fire.

Question 9.
What do you meant by hazard?
Answer:
The word ‘hazard’ owes its origin to the word ‘hazart’ in old French meaning a game of dice (in Arabic-az-zahr; in Spanish – azar).

VII. Answer the following in detail

Question 1
What is flood? What are the Major causes of flood?
Answer:
Meaning of flood :

  1. Flood is an event in which a part of the earth’s surface gets inundated.
  2. Heavy rainfall and large waves in seas are the common causes of flood.

Major causes of floods: The Major causes of floods are,
1. Meteorological Factors:

  • Heavy rainfall
  • Tropical cyclones
  • Cloud burst

2. Physical Factors:

  • Large catchment area.
  • Inadequate drainage arrangement

3. Human Factors:

  • Deforestation
  • Siltation
  • Faulty agricultural practices
  • Faulty irrigation practices
  • Collapse of dams
  • Accelerated urbanization

Samacheer Kalvi 8th Social Science Geography Solutions Term 2 Chapter 2 Hazards

Question 2.
What is cyclonic storms? Explain about the cyclonic storms.
Answer:
Cyclonic Storms:

  1. A Cyclonic storm is a strong wind circulating around a low pressure area in the atmosphere.
  2. It rotates in anti – clockwise direction in Northern Hemisphere and clockwise in the southern Hemisphere.
  3. Tropical Cyclones are characterized by destructive winds, storms surges and exceptional levels of rainfall, which may cause flooding.
  4. Wind speed may reach upto 200 Km/h and rainfall may record upto 50 cm/ day for several consecutive days.
  5. A sudden rise of seawater due to tropical cyclone is called storm surge.
  6. It is more common in the regions of shallow coastal water.

East Coastal areas vulnerable to storm surges:

  1. North Odisha and West Bengal coasts. ,
  2. Andhra Pradesh coast between Ongole and Machilipatnam.
  3. Tamil Nadu coast (among 13 coastal districts, Nagapattinam and Cuddalore districts are frequently affected).

West Coastal areas vulnerable to storm surges:

  1. The west coast of India is less vulnerable to storm surges than the east coast.
  2. Maharashtra coast, North of Hamai and adjoining South Gujarat coast and the coastal belt around the Gulf of Cambay.
  3. The coastal belt around the Gulf of Kutch.

Question 3.
Give a detailed explanation about droughts.
Answer:
Droughts:
Any lack of water to satisfy the normal needs of agriculture, livestock, industry or human population may be termed as a drought.

Classifications of drought:
The drought could be classified into three major types. They are:

1. Meteorological drought:
ft is a situation where there is a reduction in rainfall for a specific period below ‘ a specific level.

2. Hydrological drought:
It is associated with reduction of water in streams, rivers and reservoirs. It is of two types.

  • Surface water and
  • Ground water drought

3. Agricultural drought:

  • It refers to the condition in which the agricultural crops get affected due to lack of rainfall.
  • Droughts in India occur in the event of failure monsoon.

The Major areas highly prone to drought are:

  • The arid and semi arid region from Ahmadabad to Kanpur on one side and from Kanpur to Jalandhar on the other.
  • The dry region lying in the leeward side of the Western Ghats.

Samacheer Kalvi 8th Social Science Geography Solutions Term 2 Chapter 2 Hazards Read More »

Samacheer Kalvi 8th Social Science Civics Solutions Term 1 Chapter 1 How the State Government Works

You can Download Samacheer Kalvi 8th Social Science Book Solutions Guide Pdf, Tamilnadu State Board help you to revise the complete Syllabus and score more marks in your examinations.

Tamilnadu Samacheer Kalvi 8th Social Science Civics Solutions Term 1 Chapter 1 How the State Government Works

Samacheer Kalvi 8th Social Science How the State Government Works

I. Choose the correct answer

Question 1.
The Governor of a state is appointed by –
(a) President
(b) Vice President
(c) Prime Minister
(d) Chief Minister
Answer:
(a) President

Question 2.
The State Council Minsters is headed by –
(a) The Governor
(b) Chief Minister
(c) Speaker
(d) Home Minister
Answer:
(b) Chief Minister

Question 3.
Who can summon and prorogue the sessions of the State legislature?
(a) Home Minister
(b) President
(c) Speaker
(d) The Governor
Answer:
(d) The Governor

Samacheer Kalvi 8th Social Science Civics Solutions Term 1 Chapter 1 How the State Government Works

Question 4.
Who does not participate in the appointment of the High Court Judge?
(a) Governor
(b) Chief Minister
(c) Chief Justice of the High Court
(d) President of India
Answer:
(c) Chief Justice of the High Court

Question 5.
The age of retirement of the Judges of the High Court is –
(a) 62
(b) 64
(c) 65
(d) 58
Answer:
(a) 62

II. Fill in the Blanks

  1. ……………… States are there in India at present.
  2. The tenure of the Governor is normally ……………. years.
  3. The District Judges are appointed by ……………..
  4. The Governor is the ……………. Head of the State.
  5. Minimum age for elections as MLA ……………. years.

Answer:

  1. 29
  2. Five
  3. The Governor
  4. Constitutional
  5. 25

III. Match the following
Samacheer Kalvi 8th Social Science Civics Solutions Term 1 Chapter 1 How the State Government Works 1

Answer:

  1. iv
  2. ii
  3. i
  4. iii

IV. State true or false

Question 1.
Chief Minister is the chief administrator of the State.
Answer:
True

Question 2.
The Governor nominates two members of the Anglo – Indian Community to Legislative Assembly.
Answer:
False
Correct statement:
The Governor nominates one members of the Anglo- Indian Community to Legislative Assembly.

Samacheer Kalvi 8th Social Science Civics Solutions Term 1 Chapter 1 How the State Government Works

Question 3.
The number of judges in the High Courts is not uniform and fixed.
Answer:
True

V. Choose the correct statement

Question 1.
The State Legislative Assembly participates in the election of
(i) President
(ii) Vice – President
(iii) Rajya Sabha members
(iv) Members of the Legislative Council of the State

(a) i, ii & iii are Correct
(b) i & iii are Correct
(c) i, iii & iv are correct
(d) i, ii, iii & iv are correct
Answer:
(c) i, iii & iv are correct

VI. Answer the following in one or two sentences

Question 1.
Name the two houses of the State legislature.
Answer:

  • Upper house – Rajya Sabha
  • Lower house – Lok Sabha

Question 2.
Write the qualifications of the members of the Legislative Assembly?
Answer:

  1. The candidate must be a citizen of India.
  2. He/she must be 25 years and above.
  3. The candidate must be of sound mind.
  4. He/she must be an elector for any constituency in the state he is representing from.

Question 3.
How is the Chief Minister appointed?
Answer:

  • The Governor appoints the leader of the majority party in the State Legislative Assembly as the Chief Minister.
  • He is the head of the State Council of ministers.

Samacheer Kalvi 8th Social Science Civics Solutions Term 1 Chapter 1 How the State Government Works

Question 4.
How is the Council of Ministers formed?
Answer:

  1. The party which gets majority seats in the election forms the government.
  2. The leader of the majority party in the election is chosen as Chief Minister.
  3. The Chief Minister chooses his ministers from the MLAs of his party.
  4. On the advice of the Chief Minister, the Governor appoints the other ministers.
  5. Council of Ministers headed by the Chief Minister from the State Government.

VII. Answer the following in detail.

Question 1.
Discuss the powers and functions of the Chief Minister.
Answer:

  • The Chief Minister is the chief administrator of the state. All major decisions of the State Government are taken under his leadership.
  • Council of Ministers is formed by the advice of Chief minister. The Governor appoints the other Ministers.
  • The Chief Minister supervises the activities of different ministries and advises and coordinates the activities of different ministries.
  • The Chief Minister plays an important role in making policies of the State Government.
  • He has to ensure that the government policies would favour the public interest. His voice is final in the decisions of the State Government.
  • He plays an important role in making higher appointments of the State Government.
  • The Governor appoints higher officials on the advice of the Chief Minister and his Council of Ministers.

Question 2.
Discuss the powers and functions of the Legislative Assembly.
Answer:
The main duty of the Legislative Assembly is to make laws for the state. It can make law on the subjects mentioned in the state list and the concurrent list. However, during a state emergency, it cannot exercise its legislative power.

1. The assembly has control over the State Council of Ministers. The State council of ministers are responsible or answerable to the Assembly for its activities. The Assembly may pass a no-confidence motion against the council of Ministers if it is not satisfied with the performance of the council of Ministers.

2. The legislative Assembly has control over the finances of the state. A money bill can be introduced only in the Assembly. The government cannot impose, increase, lower or withdraw any tax without the approval of the Assembly.

3. The elected members of the Legislative Assembly can take part in the election of the president of India and all members can take part in the election of the members of the Rajya Sabha from the state.

4. The Assembly also takes part in the amendment of the Constitution on certain matters.

5. So the government has three basic functions: making laws, executing laws and ensuring justice.

Samacheer Kalvi 8th Social Science Civics Solutions Term 1 Chapter 1 How the State Government Works

Question 3.
Write about the powers and functions of the High Court.
Answer:
Powers and Functions of the High Court:

  • The High court has been empowered to issue writs of Habeas Corpus, Mandamus, Prohibition, Certiorari, and Quo Warranto for the enforcement of the fundamental rights and for other purposes.
  • Every High Court has a general power of superintendence over all the lower courts and tribunals within its jurisdiction except military courts and tribunals.
  • The High court controls all the subordinate courts in the state.
  • Like the Supreme Court, the High Court also acts as a Court of Record.
  • The district Court Judges were appointed by the Governor. The High Court enjoys full powers and freedom to act within its jurisdiction.
  • The Constitutional safeguards have ensured its independent working.

Samacheer Kalvi 8th Social Science Civics How the State Government Works Additional Questions

I. Choose the correct answer

Question 1.
The ……………. is an integral part of the state Legislature.
(a) Governor
(b) President
(c) Vice – President
(d) Chief Justice
Answer:
(a) Governor

Samacheer Kalvi 8th Social Science Civics Solutions Term 1 Chapter 1 How the State Government Works

Question 2.
Before the expiry of the full term of the Governor, the …………….. can dismiss him.
(a) Chief Minister
(b) Vice – president
(c) President
(d) Speaker
Answer:
(c) Presiden

Question 3.
To be the Governor, a person must have completed …………….. years of age.
(a) 25
(b) 35
(c) 21
(d) 40
Answer:
(a) 35

Question 4.
The position of the Governor of a state is compared to the ……………. of India.
(a) Chief Justice
(b) Lok Sabha speaker
(c) Attorney General
(d) President
Answer:
(d) President

Question 5.
The president declares an emergency in a state on the basis of the report of the ………………
(a) Chief Minister
(b) Governor
(c) Speaker
(d) Opposition party leader
Answer:
(b) Governor

Samacheer Kalvi 8th Social Science Civics Solutions Term 1 Chapter 1 How the State Government Works

Question 6.
As per our constitution, the strength of the Legislative council must not be less than …………..
(a) 25
(b) 30
(c) 40
(d) 35
Answer:
(c) 40

Question 7.
The members of the legislative council are elected for a term of ………….. years.
(a) 6
(b) 5
(c) 2
(d) 4
Answer:
(a) 6

Question 8.
One legislative constituency may have ………….. or even more people.
(a) 1 lakh
(b) 10 thousand
(c) 20 thousand
(d) 50 thousand
Answer:
(a) 1 lakh

Question 9.
The Governor can nominate …………… member from the Anglo – Indian community to the Legislative Assembly.
(a) 5
(b) 3
(c) 2
(d) 1
Answer:
(d) 1

Question 10.
The Legislative Assembly of Tamil Nadu located at …………….
(a) Madurai
(b) Salem
(c) Chennai
(d) Coimbatore
Answer:
(c) Chennai

II. Fill in the blanks.

  1. The states have their own executive, ……………, and ……………
  2. A Person is not appointed …………… in his own state.
  3. The …………… acts as an agent of the Central Government in a state.
  4. The …………… remains in the office so long as he gets the support of the majority members of the Legislative Assembly.
  5. The members of the …………… are elected indirectly.
  6. At present, only …………… states in India have the Legislative Council in their legislative.
  7. …………… of the members of the Legislative Council retire every two years.
  8. The …………… is the presiding officer of the Legislative Council.
  9. The people who make the laws of a state Government are called ……………
  10. Different …………… compete in the elections to the Legislative Assembly.

Answer:

  1. Legislative, Judiciary
  2. Governor
  3. Governor
  4. Chief Minister
  5. Legislative council
  6. Seven
  7. One – third
  8. Chairman
  9. Members of the Legislative Assembly
  10. Political parties

Samacheer Kalvi 8th Social Science Civics Solutions Term 1 Chapter 1 How the State Government Works

III. Match the following
Samacheer Kalvi 8th Social Science Civics Solutions Term 1 Chapter 1 How the State Government Works 2
Answer:

  1. iii
  2. i
  3. iv
  4. ii

IV. True or False

Question 1.
The Governor must give his assent to all the bills passed in the legislature
Answer:
True

Question 2.
The Chief Minister is responsible for maintaining the relationship between the central Government and the State Government.
Answer:
False
Correct statement:
The Governor is responsible for maintaining the relationship between the central Government and the State Government.

Question 3.
For the election of MLAs, the entire state is divided into different constituencies.
Answer:
True

Question 4.
There may be a common High Court only for 2 states.
Answer:
False
Correct statement:
There may be a common High Court for two or more states and Union Territories.

V. Choose the correct statement 

Question 1.
(i) A Legislative Assembly cannot have more than 500 members.
(ii) Some seats in the Legislative Assembly are reserved for scheduled castes and Scheduled tribes.
(iii) The meetings of the Assembly are presided by the chief minister.
(iv) People who have completed 21 years of age can cast their vote in the elections.

(a) i and ii are correct
(b) ii, iii and iv are correct
(c) i and iii are correct
(d) i, ii and iv are correct
Answer:
(d) i, ii and iv are correct

VI. Answer in one or two sentences

Question 1.
How is the Governor appointed?
Answer:
While appointing the Governor, the President acts as per the advice of the Union Cabinet. The State Government is also consulted when the appointment is to be made. Generally, a person is not appointed Governor in his own State.

Question 2.
What does the state executive consist of?
Answer:
The state executive consists of the Governor and the Council of Ministers headed by the Chief Minister.

Samacheer Kalvi 8th Social Science Civics Solutions Term 1 Chapter 1 How the State Government Works

Question 3.
Write short notes on the Governor of a state.
Answer:
The Governor as the Head of a State in India. He is appointed by the President of India. He is the constitutional head of a State. The Governor is appointed for a term of five years.

Question 4.
How long can the Chief Minister remain in office?
Answer:
The Chief Minister has no fixed term of office. He remains in the office so long as he gets the support of the majority members of the Legislative Assembly. When he loses support in the legislature, he has to resign.

Question 5.
How are the members of the legislative council elected?
Answer:

  1. The members of the Legislative Council are elected indirectly.
  2. One-third of its members are elected by the local government bodies like the District Panchayat and Municipalities.
  3. Another one third is elected by the members of the Legislative Assembly.
  4. One twelfth is elected by the graduates of the constituency and another one-twelfth by the teachers of secondary schools, colleges, and universities.
  5. One-sixth of the members of the Legislative Council is nominated by the Governor of the State.

Question 6.
Name the states in India which have a Legislative council.
Answer:
Bihar, Uttar Pradesh, Maharashtra, Karnataka, Jammu & Kashmir, Andhra Pradesh, and Telangana.

Question 7.
How is the capital of a state determined?
Answer:
The place where a state’s legislative assembly is located and where its council of ministers function is called the capital of that state.

Question 8.
How are the laws of the state Government executed?
Answer:
The state government has several lakhs of government employees to execute the laws made by the legislative assembly- Collectors, Tahsildars, Block Development Officers, Revenue officers, Village Administrative Officers, Policemen, Teachers, and Doctors, etc.

VII. Answer in Detail

Question 1.
Discuss the powers and functions of the Governor.
Answer:
Powers and functions
1. The Governor is the Chief Executive in a State. All the executive powers of the State are vested upon him and decisions are taken in his name. He appoints the Chief Minister and Council of Ministers.

2. He makes some important appointments such as the Advocate General, Chairman and members of the State Public Service Commission, and others.

3. The Governor also acts as the Chancellor of State Universities.

4. He summons and prorogues the sessions of the State legislature and he can dissolve the Legislative Assembly.

5. Money bills can be introduced in the State Legislative Assembly only with the approval of the Governor.

6. The annual budget of the State Government is laid before the legislature with the approval of the Governor.

7. The Contingency Fund of the State is also placed at the disposal of the Governor.

Samacheer Kalvi 8th Social Science Civics Solutions Term 1 Chapter 1 How the State Government Works

Question 2.
How are laws made in the state Government?
Answer:
In the legislative assembly meetings, MLAs discuss a number of topics like public works, education, law and order, and various problems faced by the state. The MLAs can ask questions to know the activities of ministries, which the concerned ministers have to answer. The legislative assembly makes laws on certain issues.

The process of law-making as follows:

  1. A Bill is presented in the Legislative Assembly.
  2. Debates and discussions take place on it. Changes can be made in the Bill.
  3. If more than half of the MLA’s vote in favour of the Bill, it is said to be passed.
  4. The Bill needs to get the assent of the Governor to become an Act.

Samacheer Kalvi 8th Social Science Civics Solutions Term 1 Chapter 1 How the State Government Works Read More »

Samacheer Kalvi 8th Social Science Civics Solutions Term 2 Chapter 2 Human Rights and UNO

You can Download Samacheer Kalvi 8th Social Science Book Solutions Guide Pdf, Tamilnadu State Board help you to revise the complete Syllabus and score more marks in your examinations.

Tamilnadu Samacheer Kalvi 8th Social Science Civics Solutions Term 2 Chapter 2 Human Rights and UNO

Samacheer Kalvi 8th Social Science Civics Human Rights and UNO Textbook Evaluation

I. Choose the correct answer

Question 1.
After the Second World War ……………. has taken several measures to protect the human rights.
(a) UNO
(b) Supreme Court
(c) International Court of Justice
(d) None
Answer:
(a) UNO

Samacheer Kalvi 8th Social Science Civics Solutions Term 2 Chapter 2 Human Rights and UNO

Question 2.
In 1995 women from all over the world gathered at ……………..
(a) Beijing
(b) New York
(c) Delhi
(d) None
Answer:
(a) Beijing

Question 3.
The National Human Rights Commission was constituted in ………………
(a) 1990
(b) 1993
(c) 1978
(d) 1979
Answer:
(b) 1993

Question 4.
The UNO declared 1979 as the International year of ……………..
(a) Girl Child
(b) Children
(c) Women
(d) None
Answer:
(c) Women

Question 5.
When is Human Rights Day observed?
(a) 9th December
(b) 10th December
(c) 11th December
(d) 12th December
Answer:
(b) 10th December

Samacheer Kalvi 8th Social Science Civics Solutions Term 2 Chapter 2 Human Rights and UNO

Question 6.
Which one is known as modern International Magna Carta of Human rights?
(a) UDHRC
(b) NHRC
(c) SHRC
(d) International year for women
Answer:
(a) UDHRC

Question 7.
Who can be appointed as the chairperson of the National Human Rights Commission?
(a) Retired judge of high court
(b) Any retired Chief Justice of the Supreme Court.
(c) Any person appointed by the president.
(d) Retired Chief Judge of any court.
Answer:
(c) Any person appointed by the president.

Question 8.
How many articles does the Universal Declaration of Human Rights contain?
(a) 20
(b) 30
(c) 40
(d) 50
Answer:
(b) 30

Question 9.
What is the tenure of the Chairperson of the National Human Rights Commission?
(a) 5 years or upto 62 years of age
(b) 5 years or upto 65 years of age
(c) 6 years or upto 65 years of age
(d) 5 years or upto 70 years of age
Answer:
(d) 5 years or upto 70 years of age

Samacheer Kalvi 8th Social Science Civics Solutions Term 2 Chapter 2 Human Rights and UNO

Question 10.
Where is the headquarters of the National Human Rights Commission?
(a) Delhi
(b) Mumbai
(c) Ahmedabad
(d) Kolkata
Answer:
(a) Delhi

II. Fill in the Blanks

  1. Each individual has ………….. to lead a dignified life.
  2. Human Rights are ………….. rights.
  3. The State Human Rights commission was formed on ……………
  4. Article 24 of Indian Constitution prohibits ……………
  5. United Nations Organisation was established in the year ……………

Answer:

  1. Right
  2. Fundamental rights
  3. 17th April 1997
  4. Child Labor
  5. 24th October 1945

III. Match the following:

  1. Eleanor Roosevelt – world’s first charter of human rights
  2. The Cyrus Cylinder – 1997
  3. Eve Teasing Act – freedom from slavery
  4. Child help line – Human Rights Commission
  5. Civil right – right to vote
  6. Political right – 1098

Answer:

  1. Eleanor Roosevelt – Human Rights Commission
  2. The Cyrus Cylinder – world’s first charter of human rights
  3. Eve Teasing Act – 1997
  4. Child help line – 1098
  5. Civil right – freedom from slavery
  6. Political right – right to vote

IV. State True or False

  1. Human rights and civil rights are the same.
  2. Declaration of the Rights of Man and of the Citizen was proclaimed in India.
  3. The Human Right Act of 1993 provides the creation of National Human Rights Commission.
  4. National Human Rights Commission has empowered to give punishment to the victims.
  5. ………….. was empowered to setup commission for the promotion of Human rights at National and State level.

Answer:

  1. True
  2. True
  3. False
  4. True
  5. ECOSOC

V. Consider the following statements and tick the appropriate answer

Question 1.
Find the wrong statement
(a) National Human Rights Commission is a statutory body.
(b) National Human Rights Commission is a constitutional body.
(c) National Human Rights Commission is an independent body.
(d) National Human Rights Commission is a multilateral institution.
Answer:
(b) National Human Rights Commission is a constitutional body.

Samacheer Kalvi 8th Social Science Civics Solutions Term 2 Chapter 2 Human Rights and UNO

Question 2.
Which of the following statement is not correct about the National Human Rights Commission?
(a) It was established in 1993.
(b) In the cases of human rights violation, the Commission has no rights to punish the culprit.
(c) The Chairperson and members are of this Commission are appointed by the Supreme Court of India.
(d) The Commission sends its annual report to the Central Government and State Governments.
Answer:
(c) The Chairperson and members are of this Commission are appointed by the Supreme Court of India.

Question 3.
Assertion (A) : Human Rights day is observed on 10th December
Reason (R) : It commemorates Eleanor Roosevelt’s birthday.
(a) A is correct but R does not explain A
(b) A is correct but R explains A
(c) A and R are correct
(d) A and R are Wrong
Answer:
(a) A is correct but R does not explain A

Question 4.
Consider the following statements

  1. The State Human Rights Commission is a multi-member body.
  2. The State Human Rights Commission consists of a chairperson and three members.

Which of the statements given above is /are correct?
(a) 1 only
(b) 2 only
(c) Both a and b
(d) None
Answer:
(a) 1 only

VI. Answer the following in one or two sentences

Question 1.
What are Human Rights?
Answer:

  1. Human rights are rights inherent to all human beings regardless of race, sex, nationality, ethnicity, language and religion.
  2. Human rights include freedom from slavery and torture, freedom of opinion and expression and fair trial. The right to life work and education.

Samacheer Kalvi 8th Social Science Civics Solutions Term 2 Chapter 2 Human Rights and UNO

Question 2.
Bring out the importance of UDHR.
Answer:

  1. One of the greatest achievements of United Nations is the creation of human rights law.
  2. To advance this goal, the UN established a Commission of Human Rights.
  3. it is also known as modem International Magna Carta of Human Rights.
  4. It is the most translated document in the world.

Question 3.
What does Article 45 of Indian Constitution provide?
Answer:
Article 45 of Indian Constitution provides that the state shall endeavor to provide early childhood care and education for all children until they complete the age of six years.

Question 4.
Write about Right to Education Act.
Answer:
Article 21A provides that the state shall provide free and compulsory education to all children aged six to fourteen years.

Question 5.
State any three legislation passed to safeguard the welfare of women.
Answer:

  1. The Hindu Widow Remarriage Act 1856
  2. The Hindu Marriage Act 1955.
  3. The Hindu Succession Act 1956.

Question 6.
Mention some of the political rights.
Answer:
The freedom of expression, and peaceful assembly, the right to take part in the government of one’s country, the right to vote, the freedom of speech and obtain information.

Question 7.
Name the five primary categories of Human Rights.
Answer:

  1. Civil Rights
  2. Political Rights
  3. Social Rights
  4. Economic Rights
  5. Cultural Rights

VII. Answer the following in detail:

Question 1.
Distinguish between Human rights and Civil rights.
Answer:
Human Rights:

  1. Human Rights belong to everyone, everywhere, regardless of nationality, sexuality, gender, race, religion or age.
  2. Human rights are considered universal to all human beings and universsal in all countries.
  3. No nation may rightfully deprive human rights to an individual.
  4. Human rights are basic rights inherent with birth.

Civil Rights:

  1. Civil rights are those rights that one enjoys by virtue of citizenship in a particular nation or state.
  2. Civil rights vary greatly from country to the country’s or government to government. It is related to the constitution.
  3. Different nations can grant or deny different civil rights and liberties.
  4. Civil rights are creation of the society.

Samacheer Kalvi 8th Social Science Civics Solutions Term 2 Chapter 2 Human Rights and UNO

Question 2.
Describe any five basic characteristics of Human rights.
Answer:

  1. Inherent – they are not granted by any person or authority.
  2. Fund ntal – they are fundamental rights because without them, the life and dignity of man will be meaningless.
  3. Inalienable – they cannot be taken away from the individual.
  4. Indivisible – they can’t be denied even when other rights have already been enjoyed.
  5. Universal – they are universal. They apply irrespective of one’s origin or status. They are enforceable without national border.

Question 3.
What are the measures taken by the government to protect the children?
Answer:

  1. The child is considered as an important national asset.
  2. The future of a nation depends on how its children mature and develop.
  3. So protection of children from all kinds of exploitation and abuses has become the main objective of our society.
  4. There are laws in India protecting the rights of the children.

(a) Right to Education Act:
Article 21A provides that the state shall provide free and compulsory education to all children aged six to fourteen years.

(b) The Child Labour Act (Prohibition and Regulation Act 1986):
It provides no child who has not completed 15 years of age can be employed.

(c) The Juvenile Justice Act 2000 (Care and Protection of Children):
This Act tries to protect children deprived of adequate care and to reform the children by adopting child friendly approach.

(d) POCSO A I 2012:
Protection of children from Sexual Offences Act regards the best interest of the child as being paramount importance in’every state.

VIII. HOTs

Question 1.
To whom does the Universal Declaration of Human Rights apply? Why is it important to you?
Answer:
To each individual, regardless of gender, race, religion or cultural background. Because it protects and promotes your individual rights.

IX Project and Activity

Question 1.
Make a list of 10 rights that you enjoy, and the responsibilities that you have.
Answer:
Rights :

  1. Right to life
  2. Right to family life
  3. Right to education
  4. Right to personal freedom
  5. Right to religious freedom
  6. Right to freedom of movement
  7. Freedom of press
  8. Right to equality
  9. Right to justice
  10. Freedom to form associations

Responsibilities:

  1. Support and defend the constitution
  2. Stay informed of the issues affecting your community.
  3. Participate in the democratic process.
  4. Respect and obey federal, state and local laws.
  5. Respect the rights, beliefs, and opinion of others.
  6. Participate in your local community.
  7. Serve on a jury when called upon.
  8. Defend the country if the need should arise.
  9. Pay income and other taxes honestly and on time, to federal, state and local authorities.

Samacheer Kalvi 8th Social Science Civics Human Rights and UNO Additional Questions

I. Choose the correct answer:

Question 1.
After the ……………. war, UNO has taken several measures to protect the human rights.
(a) First world
(b) Second world
(c) Third world
(d) None of these
Answer:
(b) Second world

Question 2.
In ………….. women from all over the world gathered at Beijing.
(a) 1994
(b) 1995
(c) 1999
(d) 1996
Answer:
(b) 1995

Samacheer Kalvi 8th Social Science Civics Solutions Term 2 Chapter 2 Human Rights and UNO

Question 3.
The ………….. commission was constituted in 1993.
(a) State Human Rights
(b) Local Human Rights
(c) National Human Rights
(d) Union Human Rights
Answer:
(c) National Human Rights

Question 4.
The ………….. declared 1979 as the International year of women.
(a) UNO
(b) UNESCO
(c) UDHRC
(d) SHRC
Answer:
(a) UNO

Question 5.
………….. is celeberated on 10th December every year.
(a) Valentine’s day
(b) Human Freedom Day
(c) Human Rights Day
(d) World Environment Day
Answer:
(c) Human Rights Day

Question 6.
………….. of Human Rights contain 30 Articles.
(a) Universal Declaration
(b) National Declaration
(c) State Declaration
(d) District Declaration
Answer:
(a) Universal Declaration

Question 7.
The ………….. was formed on 17th April 1997.
(a) Universal Human Rights Commission
(b) State Human Rights Commission
(c) District Human Rights Commission
(d) Local Human Rights Commission
Answer:
(b) State Human Rights Commission

Question 8.
………….. was established in the year 1945.
(a) UNESCO
(b) SHRC
(c) NHRC
(d) UNO
Answer:
(d) UNO

Samacheer Kalvi 8th Social Science Civics Solutions Term 2 Chapter 2 Human Rights and UNO

Question 9.
………….. are related to individuals and society.
(a) Human Liberty
(b) Human Rights
(c) Human Freedom
(d) Petition of Right
Answer:
(b) Human Rights

Question 10.
One of the greatest achievements of ………….. is the creation of Human Rights Law.
(a) India
(b) United Kingdom
(c) United Nation
(d) All the above
Answer:
(c) United Nation

Question 11.
Expand form of UDHR …………..
(a) United Declaration of Human Rights
(b) Universal Declaration of Human Rights
(c) Universal Development of Health Rights
(d) Universal Declaration of Health Rights
Answer:
(b) Universal Declaration of Human Rights

Question 12.
UDHR was adopted by the UN General Assemly in ……………
(a) 1948
(b) 1949
(c) 1950
(d) 1947
Answer:
(a) 1948

Question 13.
………….. refers to the basic rights afforded by law of the government to every person.
(a) Human Rights
(b) Freedom Rights
(c) Civil Rights
(d) Fundamental Rights
Answer:
(c) Civil Rights

Question 14.
………….. are exercised in the formation and administration of a government.
(a) Civil rights
(b) Political rights
(c) Social rights
(d) Economic rights
Answer:
(b) Political rights

Question 15.
The civil and Political rights are directly related to ………….. democracy.
(a) modem
(b) classical
(c) tradition
(d) all the above
Answer:
(a) modern

Question 16.
………….. rights are those rights necessary for an adequate standard of living ncluding the rights in education and health etc.
(a) Economic
(b) Civil
(c) Political
(d) Social
Answer:
(d) Social

Samacheer Kalvi 8th Social Science Civics Solutions Term 2 Chapter 2 Human Rights and UNO

Question 17.
The convention on the rights of the Rights of the child was proclaimed by UN on …………..
(a) 20th November 1989
(b) 20th December 1989
(c) 20th October 1989
(d) 20th September 1989
Answer:
(a) 20th November 1989

Question 18.
………….. provides no child who has not completed 15 years of age can be employed.
(a) POCSO Act
(b) Right to Education Act
(c) The Child Labour Act
(d) The Juvenile Justice Act
Answer:
(c) The Child Labour Act

Question 19.
UNO has declared ………….. as International.year of women.
(a) 1979
(b) 1978
(c) 1980
(d) 1961
Answer:
(b) 1978

Question 20.
………….. has declared 1979 as the International year of children.
(a) POCSO
(b) UDHRC
(c) UNO
(d) NHRC
Answer:
(c) UNO

II. Fill in the blanks:

  1. ………….. are basic rights inherent with birth.
  2. A ………….. means every human being below the age of 18 years.
  3. ………….. was adopted by UN General Assembly in 1948.
  4. In 1995 the …………… world conference of women, held in Beijing.
  5. Indian Constitution Article 39 (F) provides for …………… to develop in healthy manner.
  6. ………….. rights includes the rights to life, liberty, freedom from slavery and arbitrary arrest.
  7. The United Nations Organisation was drafted in …………….
  8. A set of basic right and freedom has deep roots in ……………. and ……………. countries.
  9. There are 30 Articles incorporated in the ……………..
  10. …………….. the great, the first king of Ancient Persia.
  11. UNO was established on …………….. 1945.
  12. …………….. during the Second World War made clear that previous efforts to protect body.
  13. Expand form of ECOSOC ……………
  14. NHRC is an …………… and …………… body.
  15. NHRC is Multi member body which consists of a …………… and other members.
  16. NHRC has ……………… division.
  17. The State Human Rights Commission of ………….. was formed on 17th April 1997.
  18. State Human Rights Commission consists of ……………. members including Chairperson.
  19. The headquarter of NHRC is located at …………….

Answer:

  1. Human Rights
  2. Child
  3. UDHR
  4. fourth
  5. Children
  6. Civil
  7. 1945
  8. European and American
  9. Universal Declaration of Human Rights
  10. Cyrus
  11. 24th October
  12. rocities
  13. The Economic and Social Council
  14. Independent statutory and non-constitutional
  15. Chairperson
  16. Five
  17. Tamil Nadu
  18. three
  19. New Delhi

III. Match the following:

Samacheer Kalvi 8th Social Science Civics Solutions Term 2 Chapter 2 Human Rights and UNO 1
Answer:

  1. e
  2. c
  3. a
  4. b
  5. d

Samacheer Kalvi 8th Social Science Civics Solutions Term 2 Chapter 2 Human Rights and UNO 2
Answer:

  1. b
  2. a
  3. e
  4. c
  5. d

IV. State True or False

  1. Every year 18th November is observed as the Human Rights Day.
  2. The Headquarters of National Human Rights Commission is situated in Mumbai.
  3. The Universal Declaration of Human Rights (UDHR) was adopted by the UN General Assembly in 1948.
  4. Human Rights are related to individual and society.
  5. There are 45 Articles incorporated in the Universal Declaration of Human Rights.
  6. Indian Constitution Article 39(f) provides for Children to develop in healthy manner.
  7. 1098 Child Line is India’s First 24 hours free emergency phone service for children in need if assistance.
  8. The National Human Rights Commission’s Chairperson and other members appointed for 6 years.
  9. The child is considered as an important national asset.
  10. UNO has declared 1979 as the international year of women.
  11. UNO has declared 1978 as international year of women.

Answer:

  1. False
  2. False
  3. True
  4. True
  5. False
  6. True
  7. True
  8. False
  9. True
  10. False
  11. True

V. Consider the following statements and Tick (✓) the appropriate answer

Samacheer Kalvi 8th Social Science Civics Solutions Term 2 Chapter 2 Human Rights and UNO

Question 1.
Find the Correct Statement:
(i) Human Rights are inherent, inalienable, interdependent and indivisible.
(ii) In 1996 the fourth world conference of women, held in Beijing.
(iii) The Dowry Prohibition Act 1961.
(iv) The UNO has declared 1979 as the International Year of Children.

(a) (i), (ii) & (iii) are Correct
(b) (i), (ii) & (iv) are Correct
(c) (i), (iii) and (iv) are Correct
(d) (ii), (iii) and (iv) are Correct
Answer:
(c) (i), (iii) and (iv) are Correct

Question 2.
Assertion (A) : Indian Constitution Article 39(f) provides for Children to develop in healthy manner.
Reason (R) : The child is considered as an important national assets.
(a) A is correct and R is the correct explanation of A
(b) A is correct but R is wrong
(c) A is correct but R is not the correct explanation of A
(d) A is incorrect but R is correct
Answer:
(a) A is correct and R is the correct explanation of A

Question 3.
Which of the following is correctly matched?
(a) The Eve Teasing Act – 1998
(b) The Hindu Succession Act – 1956
(c) The Hindu Re – Marriage Act – 1958
(d) The Hindu Marriage Act – 1856
Answer:
(b) The Hindu Succession Act – 1956

Question 4.
Which of the following is not correctly matched?
(a) The Dowry Prohibition Act – 1961
(b) The Hindu Marriage Act – 1955
(c) Indecent Representation Act – 1998
(d) Protection of Women from Domestic Violence Act – 2005
Answer:
(c) Indecent Representation Act – 1998

VI. Answer in one or two sentences:

Question 1.
List out the Four basic characteristics of Human Rights.
Answer:

  1. Inherent
  2. Fundamental
  3. Indivisible
  4. Universal

Question 2.
What do you meant by human rights?
Answer:
Human rights belong to everyone, everywhere, regardless of nationality, sexuality, gender, race, religion or age.

Question 3.
What are Civil Rights?
Answer:
Civil Rights are those rights that one enjoys by virtue of citizenship in a particular nation or state.

Samacheer Kalvi 8th Social Science Civics Solutions Term 2 Chapter 2 Human Rights and UNO

Question 4.
Write a short note on National Human Rights Commission.
Answer:

  1. The National Human Rights Commission (NHRC) of India was established on 12th October, 1993.
  2. It is an independent statutory and non – constitutional body.
  3. Its headquarter is located in New Delhi.

Question 5.
Who are them members of National Human Rights Commission (NHRC)?
Answer:
NHRC is a multi member body which consists of a Chairperson and other members. They are –

  1. Chairperson (Retired) Chief Justice of India, Judge of Supreme Court, Judge of High Court, 2 members having practical knowledge relating to Human Rights and Deemed members.
  2. Chairpersons of National Commission for Minorities, Scheduled Castes, Scheduled Tribes and Women.

Question 6.
Write a few lines about the State Human Rights Commission of Tamil Nadu.
Answer:

  1. The State Human Rights of Tamil Nadu was formed on 17th April, 1997.
  2. It function at the state level.
  3. It consists of three members including a chairperson.

Question 7.
Expand POCSO and NHRC.
Answer:

  1. POCSO : Protection of Children from Sexual Offences Act.
  2. NHRC : National Human Rights Commission

Question 8.
Define Child Rights.
Answer:
According to Article 1 of the United Nations Convention on the Rights of the Child 1989, ‘a child means every human being below the age of eighteen years’.

VII. Answer the following in detail:

Question 1.
Explain the various kinds of Human Rights.
Answer:
These rights are broadly classified into five primary categories. They are as follows:

1. Civil Rights:
The term civil rights refers to the basic rights afforded by laws of the government to every person.

2. Political Rights:

  • Political rights are exercised in the formation and administration of a government.
  • The civil and political rights are directly related to modem democracy.
  • It includes the freedom of expression and peaceful assembly, the right to take part in the government of one’s country, the right to vote, the freedom of speech and obtain information.

3. Social Rights:

  • It is necessary for an individual to fully participate in the society.
  • Social rights are those rights necessary for an adequate standard of living including the right to education, health care, food, clothing, shelter and social security.

4. Economic Rights:

  • The right to participate in an economy that benefits all and to desirable work.
  • Economic rights guarantee every person to have condition under which they are able to meed their needs.
  • This includes the rights to employment and fair wage, the reasonable limitation of working hours etc.

5. Cultural Rights:
The rights to freedom of religion and to speak the language and to practice the cultural life of the community, the right to share in scientific advancement, and right to the protection of moral and material interest.

Samacheer Kalvi 8th Social Science Civics Solutions Term 2 Chapter 2 Human Rights and UNO

Question 2.
Discuss about the Universal Declaration of Human Rights (UDHR)
Answer:

1. One of the greatest achievements of United Nations is the creation of human rights law.

2. To advance this goal, the UN established a Commission on Human Rights.

3. The Commission guided by Eleanor Roosevelt’s (Wife of former US President Franklin D Roosevelt) forceful leadership captured the world’s attention.

4. The Universal Declaration of Human Rights (UDHR) was adopted by the UN General Assembly in 1948.

5. It is a milestone document in the history of Human rights.

6. The Declaration was proclaimed by the UN General Assembly in Paris, France on 10th December 1948 (General Assembly Resolution 217A).

7. In remembrance of every year 10th December is observed as the Human rights Day and its regular observance commenced from 1950.

8. It is also known as modem International Magna Carta of Human Rights.

9. Its principles have been incorporated into the Constitutions of most of the (more than 185) nations.

10. DHR has been translated into more than 500 languages.

11. It is the most translated document in the world.

Samacheer Kalvi 8th Social Science Civics Solutions Term 2 Chapter 2 Human Rights and UNO Read More »

Samacheer Kalvi 8th Social Science History Solutions Term 1 Chapter 2 From Trade to Territory

You can Download Samacheer Kalvi 8th Social Science Book Solutions Guide Pdf, Tamilnadu State Board help you to revise the complete Syllabus and score more marks in your examinations.

Tamilnadu Samacheer Kalvi 8th Social Science History Solutions Term 1 Chapter 2 From Trade to Territory

Samacheer Kalvi 8th Social Science From Trade to Territory Textbook Evaluation

I. Choose the correct answer

Question 1.
The ruler of Bengal in 1757 was ……………
(a) Shuja – ud – daulah
(b) Siraj – ud – daulah
(c) Mirkasim
(d) Tippu Sultan
Answer:
(b) Siraj – ud – daulah

Question 2.
The Battle of Plassey was fought in ………………
(a) 1757
(b) 1764
(c) 1765
(d) 1775
Answer:
(a) 1757

Question 3.
Which among the following treaty was signed after Battle of Buxar?
(a) Treaty of Allahabad
(b) Treaty of Carnatic
(c) Treaty of Alinagar
(d) Treaty of Paris
Answer:
(a) Treaty of Allahabad]

Question 4.
The Treaty of Pondichery brought the …………….. Carnatic war to an end .
(a) First
(b) Second
(c) Third
(d) None
Answer:
(b) Second

Question 5.
When did Hyder Ali crown on the throne of Mysore?
(a) 1756
(b) 1761
(c) 1763
(d) 1764
Answer:
(b) 1761

Samacheer Kalvi 8th Social Science History Solutions Term 1 Chapter 2 From Trade to Territory

Question 6.
Treaty of Mangalore was signed between ……………..
(a) The French and Tippu Sultan
(b) Hyder Ali and Zamorin of Calicut
(c) The British and Tippu Sultan
(d) Tippu Sultan and Marathas
Answer:
(c) The British and Tippu Sultan

Question 7.
Who was the British Governor-General during the Third Anglo – Mysore War?
(a) Robert Clive
(b) Warren Hastings
(c) Lord Cornwallis
(d) Lord Wellesley
Answer:
(c) Lord Cornwallis

Question 8.
Who signed the Treaty of Bassein with the British?
(a) Bajirao II
(b) DaulatraoScindia
(c) SambhajiBhonsle
(d) SayyajiraoGaekwad
Answer:
(a) Bajirao II

Question 9.
Who was the last Peshwa of the Maratha empire?
(a) BalajiVishwanath
(b) BajiRao II
(c) BalajiBajiRao
(d) BajiRao
Answer:
(d) BajiRao

Question 10.
Who was the first Indian state to join the subsidiary Alliance?
(a) Oudh
(b) Hyderabad
(c) Udaipur
(d) Gwalior
Answer:
(b) Hyderabad

II. Fill in the Blanks

  1. The Treaty of Alinagar was signed in ……………..
  2. The commander in Chief of Sirajuddaula was ……………….
  3. The main cause for the Second Carnatic war was ……………….
  4. ………………. adopted the policy of Doctrine of Lapse to extend the British Empire in India.
  5. Tippu Sultan was finally defeated at the hands of ……………….
  6. After the death of Tippu Sultan Mysore was handed over to ……………….
  7. In 1800, ………………… established a college at Fort William in Calcutta.

Answer:

  1. 1757
  2. Mir Jafar
  3. The issue of succession
  4. Lord Dalhousie
  5. Arthur Wellesley
  6. Krishna Raja Odayar
  7. Lord Wellesley

III. Match the following

Samacheer Kalvi 8th Social Science History Term 1 Solutions Chapter 2 From Trade to Territory 1

Answer:

  1. ii
  2. iv
  3. iii
  4. V
  5. i.

IV. State true or false

Question 1.
After the death of Alivardi Khan, Siraj – ud – doula ascended the throne of Bengal.
Answer:
True

Question 2.
Hector Munro, led the British forces in the battle of Plassey.
Answer:
False
Correct statement:
Robert Clive, led the British forces in the battle of Plassey.

Question 3.
The outbreak of the Austrian war of succession in Europe was led to Second Carnatic War in India.
Answer:
False
Correct statement:
The outbreak of the Austrian war of succession in Europe was led to First Carnatic War in India.

Samacheer Kalvi 8th Social Science History Solutions Term 1 Chapter 2 From Trade to Territory

Question 4.
Sir Elijalmpey was the first Chief Justice of the Supreme Court at Fort William in Bengal.
Answer:
True

Question 5.
The Police system was created by Lord Cornwallis.
Answer:
True

V. Which one of the following is correctly matched?

  1. Battle of Adayar – 1748
  2. Battle of Ambur – 1754
  3. Battle of Wandiwash – 1760
  4. Battle of Arcot – 1749

Answer:
3. Battle of Wandiwash – 1760

VI. Answer the following in one or two sentences

Question 1.
Write a short note on Black Hole Tragedy.
Answer:

  • Black Hole Tragedy was held among a small dungeon room in the Fort William in Calcutta, where troops of the Nawab of Bengal Siraj-ud-daula, held 146 British Prisoners of war for one night.
  • The next day morning, when the door was opened 123 of the prisoners found dead because of suffocation.

Question 2.
What were the benefits derived by the English after the Battle of Plassey?
Answer:
After the Battle of Plassey in 1757, the company was granted undisputed right to have free trade in Bengal, Bihar and Orissa. It received the place of 24 Parganas in Bengal.

Question 3.
Mention the causes for the Battle of Buxar.
Answer:

  • Shuja-ud-daulah and Shah Alam II formed a confederacy.
  • They both got angry with the British for misusing the free duty passes.

Question 4.
What were the causes for the First Mysore War?
Answer:
Causes:

  1. Haider Ali’s growing power and his friendly relations with the French became a matter of concern for the English East India Company.
  2. The Marathas, the Nizam and the English entered into a triple alliance against Haider Ali.

Question 5.
Bring out the results of the Third Maratha War.
Answer:

  1. The Maratha confederacy was dissolved and Peshwaship was abolished.
  2. Most of the territory of Peshwa BajiRao II was annexed and became part of the Bombay Presidency
  3. The defeat of the Bhonsle and Holkar also resulted in the acquisition of the Maratha kingdoms of Nagpur and Indore by the British.
  4. The BajiRao II, the last Peshwa of Maratha was given an annual pension of 8 lakh rupees.

Samacheer Kalvi 8th Social Science History Solutions Term 1 Chapter 2 From Trade to Territory

Question 6.
Name the states signed into Subsidiary Alliance.
Answer:
Hyderabad (1798). It was followed by Tanjore (1799), Aundh (1801), Peshwa (1802), Bhonsle (1803), Gwalior (1804), Indore (1817), Jaipur, Udaipur and Jodhpur (1818).

VII. Answer the following in detail

Question 1.
Write an essay on second Carnatic war.
Answer:

Second Carnatic war:

  • Succession in the war of Carnatic and Hyderabad was the main cause for the Second Carnatic war.
  • Anwar-ud-din-Khan and Chanda Sahib were the two claimants to the throne of Carnatic, whereas Nasir Jang and Muzaffar Jang were the claimants to the throne of Hyderabad.
  • French supported Muzaffar Jang and Chanda Sahib and the British supported other claimants.

Alliance:
Dupleix, Chanda Sahib, Muzaffar Jang formed a grand alliance.

Battle of Ambur( 1749):

  • The grand alliance defeated and killed Anwar-ud-din khan, the Nawab of Carnatic, Chanda Shahib, and rewarded 80 villages to the French around Pondicherry.
  • In the Deccan, the French defeated Nasir Jang and made Muzaffar Jang as the Nizam. Dupleix’s power was at its zenith at that time as he was the governor of all territories.

Battle of Arcot (1751):

  • Dupleix sent forces to besiege the fort of Trichy where Muhammed Ali had taken shelter. Chanda Sahib also joined the French.
  • Robert Clive’s proposal was accepted by the British governor, Saunders. With 200 English soldiers and 300 Indian soldiers, the task of capturing Arcot was entrusted.
  • Clive defeated the French and made Muhammad Ali the Nawab of Arcot.
  • The French recalled Dupleix to Paris.

Treaty of Pondicherry (1755):

  • Dupleix was succeeded by Godeheu with the agreement of the treaty of Pondicherry. This treaty made the British stronger.
  • The second Carnatic war was proved inconclusive.

Question 2.
Give an account of the Fourth Anglo Mysore war.
Answer:
The Fourth Anglo – Mysore War:
Tipu Sultan did not forget the humiliating treaty of Srirangapatnam imposed upon him by Cornwallis in 1790.
Causes:

  1. Tipu sought alliance with foreign powers against the English and sent ambassadors to Arabia, Turkey, Afghanistan and the French.
  2. Tipu was in correspondence with Napoleon who invaded Egypt at that time.
  3. The French officers came to Srirangapatnam where they founded a Jacobin Club and planted the Tree of Liberty.

Course:

1. Wellesley declared war against Tipu in 1799. The war was short and decisive. As planned, the Bombay army under General Stuart invaded Mysore from the west.

2. The Madras army, which was led by the Governor – General’s brother, Arthur Wellesley, forced Tipu to retreat to his capital Srirangapatnam.

3. On 4th May 1799 Srirangapatnam was captured. Tipu fought bravely and was killed finally. Thus ended the fourth Mysore War and the whole of Mysore lay prostrate before the British.

Mysore after the War:

  1. The English occupied Kanara, Wynad. Coimbatore. Darapuram and Srirangapattinam.
  2. Krishna Raja Odayar of the former Hindu royal family was brought to the throne.
  3. Tipu’s family was sent to the fort of Vellore.

Question 3.
Describe the policy adopted by Lord Dalhousie to expand the British empire in India.
Answer:

  • Lord Dalhousie introduced the Doctrine of Lapse. He was the chief architect of the British Empire in India.
  • Those who are adopted sons their property undertaken by the British.
  • This Principle called as ‘Doctrine of Lapse’ It was bitterly opposed by the Indians and it was one of the root causes of the great revolt of 1857.

Samacheer Kalvi 8th Social Science History Solutions Term 1 Chapter 2 From Trade to Territory

Question 4.
How did Lord Wellesley expand the British
Answer:
The Subsidiary Alliance:

  1. Lord Wellesley introduced the system of Subsidiary Alliance to bring the princely states under the control of the British.
  2. It was the most effective instrument for the expansion of the British territory and political influence in India.
  3. The princely state was called ‘the protected state’ and the British came to be referred as ‘the paramount power’.
  4. It was the duty of the British to safeguard the state from external aggression and to help its ruler in maintaining internal peace.

Main Features of Subsidiary Alliance:

  1. An Indian ruler entering into this alliance with the British had to dissolve his own armed forces and accept British Forces.
  2. A British Resident would stay in his capital.
  3. Towards the maintenance charges of the army, he should make annual payments or cede some territory permanently to the Company.
  4. All the non – English European officials should be turned out of his state.
  5. The native ruler should deal with foreign states only through the English Company.
  6. The British would undertake to defend the state from internal trouble as well as external attack.

VIII. HOTS

Question 1.
Explain the causes of the success of the English in India.
Answer:

  • The succession in the Carnatic war by the British made them powerful at the end of the third Carnatic war. French dominance came to an end.
  • The British introduced the Subsidiary Alliance to bring the princely states under their control by Lord Wellesley.
  • The Doctrine of Lapse adopted by Lord Dalhousie to extend the empire. Through this policy, the kingdoms where its rulers have adopted sons would go to the paramount power of the British. Thus it caused the success of the English in India.

IX. Mark the following on the River map of India

Question 1.

  1. Plassy
  2. Buxar
  3. Purandhar
  4. Arcot
  5. Wandiwash

Answer:
Samacheer Kalvi 8th Social Science History Term 1 Solutions Chapter 2 From Trade to Territory 2

Samacheer Kalvi 8th Social Science History  From Trade to Territory Additional Questions

I. Choose the correct answer

Question 1.
The rule of …………… in India became effective after the conquest of Bengal.
(a) Mughals
(b) East India Company
(c) Portuguese
(d) French
Answer:
(b) East India Company

Question 2.
Siraj – ud – daula captured the British factory at …………….
(a) Kasim Bazar
(b) Delhi
(c) Alinagar
(d) Chandranagore
Answer:
(a) Kasim Bazar

Question 3.
Buxar was a small fortified town in the territory of ……………….
(a) West Bengal
(b) Karnataka
(c) Bihar
(d) Rajasthan
Answer:
(c) Bihar

Question 4.
In the battle of Adayar, the French army fought under captain ……………..
(a) Hector Munro
(b) Robert Clive
(c) Eyre Coote
(d) Paradise
Answer:
(d) Paradise

Question 5.
Under the terms of the Treaty of Aix – la – Chapelle, ……………. was returned back to the English.
(a) Madras
(b) Trichinopoly
(c) Hyderabad
(d) Calcutta
Answer:
(a) Madras

Question 6.
The outbreak of the seven years was in Europe led to the ……………. war in India.
(a) I Carnatic
(b) II Carnatic
(c) III Carnatic
(d) Wandiwash
Answer:
(c) III Carnatic

Question 7.
In the III Carnatic war, France captured Fort ……………
(a) Gwalior
(b) St. David
(c) William
(d) Vellore
Answer:
(b) St. David

Samacheer Kalvi 8th Social Science History Solutions Term 1 Chapter 2 From Trade to Territory

Question 8.
The Battle of Wandiwash was fought by the English army under General …………….
(a) Forde
(b) Dupleix
(c) Hector Munro
(d) Eyre Coote
Answer:
(d) Eyre Coote

Question 9.
The Seven year’s war was concluded …………… by the treaty of.
(a) Paris
(b) Pondicherry
(c) Madras
(d) Mangalore
Answer:
(a) Paris

Question 10.
The state of Mysore rose to prominence under the leadership of …………….
(a) Chanda sahib
(b) Salabat Jang
(c) Haider Ali
(d) MirJafar
Answer:
(c) Haider Ali

Question 11.
In 1781, the British General Sir Eyre Coote defeated Haider Ali at ………………
(a) Hyderabad
(b) Porto Novo
(c) Mysore
(d) Mangalore
Answer:
(b) Porto Novo

Question 12.
………….. Saved the British Dominion from the wrath of powerful enemies.
(a) Wellesley
(b) Cornwallis
(c) Warren Hastings
(d) Dalhousie
Answer:
(c) Warren Hastings

Question 13.
Tipu attacked in ……………. 1789.
(a) Madras
(b) Mangalore
(c) Mahe
(d) Travancore
Answer:
(d) Travancore

Question 14.
During the course of the third Anglo – Mysore war …………… took the command of the British Army.
(a) Cornwallis
(b) Dalhousie
(c) Robert Clive
(d) Curzon
Answer:
(a) Cornwallis

Question 15.
The internal conflict among the ……………. was best utilised by the British.
(a) Nizams
(b) Marathas
(c) Nawabs
(d) Chauhans
Answer:
(b) Marathas

Question 16.
Colonel Upton concluded the treaty of ……………. in 1776.
(a) Mangalore
(b) Mysore
(c) Purandhar
(d) Pondicherry
Answer:
(c) Purandhar

Question 17.
The death of …………….. in 1800 gave the British an added advantage.
(a) Mahadaji Scindia
(b) Daulat Rao Scindia
(c) Madhav Rao
(d) Nana Phadnavis
Answer:
(d) Nana Phadnavis]

Question 18.
In the III Anglo Maratha war, Hastings was supported by a force under General ……………
(a) Thomas Hislop
(b) Mathews
(c) Medows
(d) Upton
Answer:
(a) Thomas Hislop]

Samacheer Kalvi 8th Social Science History Solutions Term 1 Chapter 2 From Trade to Territory

Question 19.
……………… the Governor-General of India in 1786, enforced the ruler against private trade.
(a) Warren Hastings
(b) Wellesley
(c) Cornwallis
(d) Robert Clive
Answer:
(c) Cornwallis

Question 20.
As per the Government of India Act of 1858, the maximum age for competitors of civil services examination was fixed at ……………
(a) 20
(b) 23
(c) 25
(d) 21
Answer:
(b) 23

II. Fill in the blanks

  1. ………………. of Portugal discovered a new sea route from Europe to India.
  2. ………………. ascended the throne of Bengal in 1756.
  3. British captured …………….. the French settlement in 1757.
  4.  ………………. concluded two treaties with Siraj – Ud – daula and Shah Alam II.
  5. ………………. and ……………… were rival countries in Europe.
  6. The battle of ………………… was fought between the French forces and forces of Anwar – ud – din.
  7. ……………. was deputed from France to conduct the third Carnatic war.
  8. Robert Clive sent ………….. from Bengal to occupy the Northern Circars.
  9. Haider Ali and his son …………. played a prominent role against the expansion of the British empire in India.
  10. The Nizam, with the help of British troops led by General invaded Mysore in 1767.
  11. Tipu captured Brigadier …………. the supreme commander of the forces in 1783.
  12. After the death of Narayan Rao, ……………. became the Peshwa.
  13. Raghunath Rao’s authority was challenged by a strong party at Poona under ……………..
  14. ……………. made an attempt to form a coalition of Indian rulers to fight against the British.
  15. The Royal Commission on Public Service was Chaired by Lord ……………. in 1912.
  16. In 1918 ………….. and ……………. recommended that 33% of Indians should be recruited in Indian civil services.
  17. The …………….. was the second important pillar of the British administration in India.
  18. The highest rank in the army that an Indian could ever reach was that of a ……………..
  19. Circles or Thanas were headed by a …………….
  20. The hereditary village police became ……………

Answer:

  1. Vasco da Gama
  2. Siraj – Ud – daula
  3. Chandra nagore
  4. Robert Clive
  5. Britain and France
  6. San Thome (Madras)
  7. Count de Lally
  8. Colonel Forde
  9. Tipu Sultan
  10. Joseph Smith
  11. Mathews
  12. Raghunath Rao
  13. Nana Phadnavis
  14. Yashwant Rao Holkar
  15. Islington
  16. Montague, Chelmsford
  17. Army
  18. Subedar
  19. Daroga
  20. Chowkidars

III. Match the following

Samacheer Kalvi 8th Social Science History Term 1 Solutions Chapter 2 From Trade to Territory 3

Answer:

  1. iii
  2. i
  3. iv
  4. v
  5. ii

IV. State true or false

Question 1.
Within a year after the Battle of Wandiwash the English army totally routed the French Army.
Answer:
True

Question 2.
In 1761, Tipu Sultan became the de facto ruler of Hyderabad.
Answer:
False
Correct statement:
In 1761, Tipu Sultan became the de facto ruler of Mysore.

Samacheer Kalvi 8th Social Science History Solutions Term 1 Chapter 2 From Trade to Territory

Question 3.
Warren Hastings consolidated the British power in India.
Answer:
True

Question 4.
The Treaty of Salbai was signed between Cornwallis and Mahadaji Scindia.
Answer:
False
Correct statement:
The Treaty of Salbai was signed between Warren Hastings and Mahadaji Scindia.

Question 5.
The idea of competition for recruitment was introduced first by the Charter Act, 1833.
Answer:
True

V. Answer the following in one or two sentences.

Question 1.
What was the motive behind the discovery of sea routes to India?
Answer:
The main motive behind those discoveries was to maximize profit through trade and to establish political supremacy.

Question 2.
What were the causes of the Second Anglo Mysore war?
Answer:
1. The English did not fulfill the terms of the treaty of 1769, when Haider’s territories were attacked in 1771 by Marathas, Haider did not get help from the British.

2. British captured Mahe, a French settlement within Haider’s Jurisdiction. It led to the formation of an alliance by Haider with the Nizam and Marathas against the English in 1779.

Question 3.
Prepare flow chart to explain the period of the three Carnatic Wars.
Answer:
Samacheer Kalvi 8th Social Science History Term 1 Solutions Chapter 2 From Trade to Territory 4

Question 4.
What were the results of the First Anglo Maratha War?
Answer:

  1. Raghunath Rao was pensioned off and MadhavRao II was accepted as the Peshwa.
  2. Salsette was given to the British.
  3. The Treaty of Salbai established the British influence in Indian politics. It provided the British twenty years of peace with the Marathas.

Question 5.
Explain with a flow chart the period of the Anglo Mysore wars.
Answer:
Samacheer Kalvi 8th Social Science History Term 1 Solutions Chapter 2 From Trade to Territory 5

Question 6.
Prepare a flow chart mentioning the period in which the Anglo Maratha wars were fought.
Answer:
Samacheer Kalvi 8th Social Science History Term 1 Solutions Chapter 2 From Trade to Territory 6

Question 7.
What did the Indian Civil Service Act of 1861 state?
Answer:
The Indian Civil Service Act of 1861 passed by the British Parliament exclusively reserved certain categories of high executive and judicial posts for the covenanted civil service which was later designated as the Indian Civil Service.

Question 8.
Name the three Indians who became successful in the I.C.S. examination in 1869.
Answer:
In 1869, three Indians – Surendra Nath Banerjee, Ramesh Chandra Dutt and Bihari Lai Gupta became successful in the I.C.S. examination.

Question 9.
What did the Royal Commission of Public Service or the Lee Commission recommend in 1923?
Answer:
In 1923, a Royal Commission on Public Services was appointed with Lord Lee of Fareham as chairman. This commission recommended that recruitment to all-Indian services like the Indian Civil Service, the Indian Police Service and the Indian Forest Service should be made and controlled by the Secretary of State for India. The Lee Commission recommended the immediate establishment of a Public Service Commission.

Samacheer Kalvi 8th Social Science History Solutions Term 1 Chapter 2 From Trade to Territory

Question 10.
Write a short note on the Act of 1935.
Answer:
The Act of 1935 also made provisions for the establishment of a Federal Public Service Commission at the Centre and the Provincial Public Service Commissions in the various provinces. Provision was also made for a Joint Public Service Commission in two or more Provinces. Although, the main aim of this measure was to serve the British interests, it became the base of the civil service system in independent India.

Question 11.
Name the provinces in which separates armies were organised during the British rule.
Answer:
During the early stage of British rule, three separate armies had been organised in three Presidencies of Bengal, Bombay and Madras.

Question 12.
Name the places where high courts were set up according to the Act of 1861.
Answer:
According to the Indian High Courts Act, 1861, three High Courts were set up in Calcutta, Bombay and Madras.

Question 13.
Brief the merits of the subsidiary Alliance for the British.
Answer:
Merits for the British:

  1. The British Company maintained a large army at the expense of the Indian rulers.
  2. All Frenchmen in the service of native rulers were dismissed, and the danger of French revival was completely eliminated.
  3. The British Company began to control the foreign policy of the Princely States,
  4. Wellesley’s diplomacy made the British the paramount power in India. He transformed the British Empire in India into the British empire of India.

Samacheer Kalvi 8th Social Science History Solutions Term 1 Chapter 2 From Trade to Territory

Question 14.
What were the factors for the success of the British?
Answer:
Factors for the success of the British:

  1. Greater naval power.
  2. Development of textile.
  3. Scientific division of labour.
  4. Economic prosperity and skillful diplomacy of the British.
  5. Feelings of insecurity among the Indian merchants.
  6. The inequality and ignorance of the Indian kings.

Question 15.
What was the impact of the policies of Subsidiary Alliance and Doctrine of Lapse in India?
Answer:
This policy led to a South Indian rebellion (1800 – 01), Vellore Rebellion (1806) and the Great Rebellion (1857).

Samacheer Kalvi 8th Social Science History Solutions Term 1 Chapter 2 From Trade to Territory Read More »

Samacheer Kalvi 8th Science Solutions Term 2 Chapter 2 Electricity

You can Download Samacheer Kalvi 8th Science Book Solutions Guide Pdf, Tamilnadu State Board help you to revise the complete Syllabus and score more marks in your examinations.

Tamilnadu Samacheer Kalvi 8th Science Solutions Term 2 Chapter 2 Electricity

Samacheer Kalvi 8th Science Electricity Text Book Exercises

I. Chosse the best answer

Question 1.
When an ebonite rod is rubbed with fur, the charge acquired by the fur is –
(a) negative
(b) positive
(c) partly positive and partly negative
(d) None of these
Answer:
(b) positive
Samacheer Kalvi 8th Science Solutions Term 2 Chapter 2 Electricity

Question 2.
The electrification of two different bodies on rubbing is because of the transfer of –
(a) neutrons
(b) protons
(c) electrons
(d) protons and neutrons
Answer:
(c) electrons

Question 3.
Which of the following a simple circuit must have?
(a) Energy Source, Battery, Load
(b) Energy Source, Wire, Load
(c) Energy Source, Wire, Switch
(d) Battery, Wire, Switch
Answer:
(d) Battery, Wire, Switch

Question 4.
An electroscope has been charged by induction with the help of charged glassrod. The charge on the electroscope is –
(a) negative
(b) positive
(c) both positive and negative
(d) None of the above
Answer:
(b) positive

Question 5.
Fuse is –
(a) a switch
(b) a wire with low resistanceFuse is
(c) a wire with high resistance
(d) a protective device for breaking an electric circuit
Answer:
(d) a protective device for breaking an electric circuit

II. Fill in the blanks

  1. ……………. takes place by rubbing objects together.
  2. The body which has not lost electrons becomes …………….
  3. ……………. is a device that protects building from lightning strike.
  4. ……………. has a thin metallic filament that melts and breaks the connection when the circuit is overheated.
  5. Three bulbs are connected end to end from the battery. This connection is called …………….

Answer:

  1. Transfer of electron
  2. positive
  3. Lightning arrestor
  4. Electric fuse
  5. series circuit

III. State True or False. If false, correct the statement

Question 1.
The charge acquired by an ebonite rod rubbed with a piece of flannel is negative.
Answer:
True

Samacheer Kalvi 8th Science Solutions Term 2 Chapter 2 Electricity

Question 2.
A charged body induces an opposite charge on an uncharged body when they are brought near.
Answer:
True

Question 3.
Electroscope is a device used to charge a body by induction.
Answer:
True

Question 4.
Water can conduct electricity.
Answer:
True

Question 5.
In parallel circuit, current remains the same in all components.
Answer:
False
Correct statement:
In parallel circuit, voltage remains the same in all components.

IV. Match the following

Question 1.

  1. Two similar charges – acquires a positive charge
  2. Two dissimilar charges – prevents a circuit from overheating
  3. When glass rod is rubbed with silk – repel each other
  4. When ebonite rod is rubbed with fur – attract each other
  5. Fuse – acquires a negative charge

Answer:

  1. Two similar charges – repel each other
  2. Two dissimilar charges – attract each other
  3. When glass rod is rubbed with silk – acquires a positive charge
  4. When ebonite rod is rubbed with fur – acquires a negative charge
  5. Fuse – prevents a circuit from overheating

V. Give reason for tile following.

Question 1.
When a glass rod is rubbed with silk cloth, both get charged.
Answer:
Reason:
When a glass rod is rubbed with a silk cloth the free electrons in the glass rod are transferred to silk cloth. It is because the free electrons in the glass rod are less tightly bound as compared to that in silk cloth. Since the glass rod looses electrons, it has a deficiency of electrons and hence acquires positive charge. But, the silk cloth has excess of electrons. So, it becomes negatively charged.

Question 2.
When a comb is rubbed with dry hair, it attracts small bits of paper.
Answer:
Reason:
Comb rubbed with hair gains electrons from the hair and becomes negatively charged. These electrons are accumulated on the surface of the comb. When a piece of paper is teared into bits, positive and negative charges are present at the edges of the bits. Negative charges in the comb attract positive charges in the bits. So, the paper bits are moving towards the comb.

Question 3.
When you touch the metal disc of an electroscope with a charged glass rod the metal leaves get diverged.
Answer:
Reason:
The leaves of an electroscope diverge because when a glass rod is touched on the metal disc, the charge travels through the metal rod to the leaves. Since, like charge repel, the charge travels till the leaves and then open up as both the leaves have like charges.

Samacheer Kalvi 8th Science Solutions Term 2 Chapter 2 Electricity

Question 4.
In an electroscope the connecting rod and the leaves are all metals.
Answer:
Reason:
These are made of metals so that the electrons become free to move.

Question 5.
One should not use an umbrella while crossing an open field during thunderstorm.
Answer:
Reason:

  1. Carrying an umbrella is not advisable during thunderstorm.
  2. As the rod of umbrella and its supporting wires are made up of metals.
  3. Thus during thunderstorm, the conducting object should be avoided.

VI. Choose the correct answer from the following directions.

Question 1.
(a) If both assertion and reason are true and reason is the correct explanation of the assertion.
(b) If both assertion and reason are true and reason is not the correct explanation of assertion.
(c) If the assertion is true, but reason is false.
(d) If the assertion is false but reason is true.

Question 1.
Assertion : People struck by lightning receive a severe electrical shock.
Reason : Lightning carries very high voltage.
Answer:
(a) Both assertion and reason are true and reason is the correct explanation of assertion.

Question 2.
Assertion : It is safer to stand under a tall tree during lightning.
Reason : It will make you the target for lightning.
Answer:
(d) The assertion is false but reason is true

VII. Answer briefly

Question 1.
How charges are produced by friction?
Answer:
Rubbing certain materials with one another can cause the built-up of electrical charges on the surfaces. So charges are produced by friction.
Example:
Combing hair charges are transferred from the hair to comb due to friction.

Samacheer Kalvi 8th Science Solutions Term 2 Chapter 2 Electricity

Question 2.
What is Earthing?
Answer:
Earthing is the process of connecting the exposed metal parts of an electrical circuit to the ground.

Question 3.
What is electric circuit?
Answer:
The path through which electrons flow from one terminal to another terminal of the source, is called electric circuit.

Question 4.
What is electroplating?
Answer:
The process of depositing a layer of one metal over the surface of another metal by passing electric current is called electroplating.

Question 5.
Give some uses of electroplating.
Answer:
Electro plating is applied in many fields:

  1. We use iron in bridges and automobiles to provide strength.
  2. A coating of zinc is deposited on iron to protect it from corrosion and formation of rust.
  3. Chromium has a shiny appearance. It does not corrode.
  4. It resists scratches.

VIII. Answer is detail

Question 1.
Explain three ways of charge transfer.
Answer:
Transfer of charges takes place in the following three ways:

  1. Transfer by Friction
  2. Transfer by Conduction
  3. Transfer by Induction

1. Transfer by Friction:
This method of charging an uncharged body by rubbing it ; against another body is called charging by friction.
Example:
While combing hair charges are transferred from the hair to comb due to friction.

2. Transfer by conduction:
Charges can be transferred to on object by bringing it in contact with a charged body. This method of transferring charges from one body to other body is calledtransfer by conduction.
Example:
When the ebonite rod is rubbed with woollen cloth, electrons from the woollen cloth are transferred to the ebonite rod. Now ebonite rod will be negatively charged.

(i) When it is brought near the paper cylinder, negative charges in the rod are attracted by the positive charges in the cylinder.

(ii) When the cylinder is touched by the rod, some negative charges are transferred to the paper. Hence, the negative charges in the rod are repelled by the negative charges in the cylinder.

3. Transfer by Induction:
The process of charging an uncharged body by bringing a charged body near to it but without touching it is called induction.
Example:
we can charge an uncharged object when we touch it by a charged object. But, it is also possible to obtain charges in a body without any contact with other charges.

Samacheer Kalvi 8th Science Solutions Term 2 Chapter 2 Electricity

Question 2.
What is electroscope? Explain how it works?
Answer:
1. An electroscope is a scientific instrument used to detect the presence of electric charge on a body.

2. An electroscope is made out of conducting materials, generally metal.

3. It works on the principle that like charges repel each other.

4. In a simple electroscope two metal sheets are hung in contact with each other.

5. They are connected to a metal rod that extends upwards, and ends in a knob at the end.

Samacheer Kalvi 8th Science Solutions Term 2 Chapter 2 Electricity 1

6. If you bring a charged object near the knob, electrons will either move out of it or into it.

7. This will result in charges on the metal leaves inside the electroscope.

8. If a negatively charged object is brought near the top knob of the electroscope, it causes free electrons in the electroscope to move down into the leaves, leaving the top positive..

9. Since both the leaves have negative charge, they repel each other and move apart.

10. If a positive object is brought near the top knob of the electroscope, the free electrons in the electroscope start to move up towards the knob.

11. This means that the bottom has a net positive charge. The leaves will spread apart again. Explain series and parallel circuit.

Question 3.
Explain series and parallel circuit.
Answer:
Series Circuit:
Samacheer Kalvi 8th Science Solutions Term 2 Chapter 2 Electricity 2

  1. A series circuit is one that has more than one resistor (bulb) but only one path through which the electrons can travel.
  2. From one end of the battery the electrons move along one pathwith no branches through the resistors (bulbs) to the other end of the cell.
  3. All the components in a series circuit are connected end to end.
  4. So, current through the circuit remains same throughout the circuit.
  5. But, the voltage gets divided across the bulbs in the circuit.
  6. In the following series circuit two bulbs are used as resistors.
  7. Let I be the current through the circuit and V1 V2, V3 be the voltage across each bulb.
  8. The supply voltage V is the total of the individual voltage drops across the resistances. V = V1 + V2 + V3

Parallel Circuit:
Samacheer Kalvi 8th Science Solutions Term 2 Chapter 2 Electricity 3

  1. In a parallel circuit, there is more than one resistor (bulb) and they are arranged on many paths.
  2. This means charges (electrons) can travel from one end of the cell through many branches to the other end of the cell.
  3. Here, voltage across the resistors (bulbs) remains the same but the current flowing through the circuit gets divided across each resistor.
  4. Let us consider three bulbs connected in series.
  5. Let V be the voltage across the bulbs and I1, I2, I3 be the current across each bulb.
  6. The current I from the battery is the total of the individual current flowing through the resistances. I = I1 + I2 + I3

Samacheer Kalvi 8th Science Solutions Term 2 Chapter 2 Electricity

Question 4.
How lightning takes place?
Answer:
1. Lightning is produced by discharge of electricity from cloud to cloud or from cloud to ground.

2. During thunderstorm air is moving upward rapidly.

3. This air which moves rapidly, carries small ice crystals upward.

4. At the same time, small water drops move downward.

5. When they collide, ice crystals become positively charged and move upward and the water drops become negatively charged and move downward.
Samacheer Kalvi 8th Science Solutions Term 2 Chapter 2 Electricity 4
6. So the upper part of the cloud is positively charged and the lower part of the cloud is negatively charged.

7. When they come into contact, electrons in the water drops are attracted by the positive charges in the ice crystals. Thus, electricity is generated and lightning is seen.

8. Sometimes the lower part of the cloud which is negatively charged comes into contact with the positive charges accumulated near the mountains, trees and even people on the earth. This discharge produces lot of heat and sparks that results in what we see as lightning.

Question 5.
What is electroplating? Explain how it is done.
Answer:
Electroplating:
Samacheer Kalvi 8th Science Solutions Term 2 Chapter 2 Electricity 5

  1. Electroplating is one of the most common applications of chemical effects of electric current.
  2. The process of depositing a layer of one metal over the surface of another metal by passing electric current is called electroplating.
  3. Take a glass jar and fill it with copper sulphate solution.
  4. Take a copper metal plate and connect it to the positive terminal of battery.
  5. Connect an iron spoon to the negative terminal of the battery.
  6. Now, dip them in the copper sulphate solution.
  7. When electric current is passed through the copper sulphate solution, you will find that a thin layer of copper metal is deposited on the iron spoon and an equivalent amount of copper is lost by the copper plate.

Samacheer Kalvi 8th Science Electricity Intex Activities

Activity – 1

Question 1.
Take a comb and place it near some pieces of paper. Are they attracted by the comb? No. Now comb your dry hair and place it near them. What do you see? You can see that the paper pieces are attracted by the comb now. How is it possible?
Answer:
Reason:
Comb rubbed with hair gains electrons from the hair and becomes negatively charged. These electrons are accumulated on the surface of the comb. When a piece of paper is teared into bits, positive and negative charges are present at the edges of the bits. Negative charges in the comb attract positive charges in the bits. So, the paper bits are moving towards the comb.

Activity – 2

Question 1.
Take a sheet of paper. Turn it into a hollow cylinder. Tie one end of the cylinder with a silk thread and hang it from a stand. Now take an ebonite rod and charge it by rubbing it with a woollen cloth. Bring this charged ebonite rod near the paper cylinder. The cylinder will be attracted by the rod. If you touch the paper cylinder by the charged rod, you will see the paper cylinder repelling the rod. Can you give the reason?
Answer:
When the cylinder is touched by the rod, some negative charges are transferred to the paper. Hence, the negative charges in the rod are repelled by the negative charges in the cylinder.

Activity – 4

Question 1.
Rub your foot on a carpet floor and touch a door knob. What do you feel? Do you feel the shock in your hand? Why does this happen?
Answer:
Samacheer Kalvi 8th Science Solutions Term 2 Chapter 2 Electricity 6
Getting a shock from a doorknob after rubbing your foot on a carpet floor, results from discharge. Discharge occurs when electrons on the hand are quickly pulled to the positively charged doorknob. This movement of electrons, which is felt as a shock, causes the body to lose negative charge.

Activity – 5

Question 1.
Take two pieces of wire, an LED light and a battery, and make a simple electric circuit. Take some water in a glass and put the wires in the water as shown in the figure. Does the LED bulb glow? What do you understand from this?
Samacheer Kalvi 8th Science Solutions Term 2 Chapter 2 Electricity 7
Answer:
Yes, the LED bulb glows. From this Activity we understood that liquids also conduct electricity.

Activity – 7

Question 1.
Take a battery, a bulb, a switch and few connecting wires. Make an electric circuit as shown in the figure. Keep the switch in the ‘OFF’ position. Does the bulb glow?
Answer:
No, the bulb does not glow.
Samacheer Kalvi 8th Science Solutions Term 2 Chapter 2 Electricity 8

Question 2.
Now move the electric switch to the ‘ON’ position and let the bulb glow for a minute or so. Touch the bulb now. Do you feel the heat?
Answer:
Yes, the bulb is hot because electrical energy is transformed to heat energy. This is known as heating effect of electric current.

Samacheer Kalvi 8th Science Electricity Additional Questions

I. Choose the correct answer

Question 1.
Electroplating is based on ……………… effect of electricity.
(a) magnetic
(b) chemical
(c) heating
(d) physical
Answer:
(b) chemical

Samacheer Kalvi 8th Science Solutions Term 2 Chapter 2 Electricity

Question 2.
A positively charged object will attract ……………… charged object.
(a) positively
(b) negatively
(c) both a and b
(d) none
Answer:
(b) negatively

Question 3.
The method of charging an object by touching is called ………………
(a) induction
(b) diffusion
(c) current
(d) conduction
Answer:
(d) conduction

Question 4.
Lighting occurs due to ……………….
(a) rain
(b) humidity
(c) wind
(d) electric discharge
Answer:
(d) electric discharge

Question 5.
Electric charge can be transferred from a charged object to another through ……………….
(a) vacuum
(b) conductor
(c) air
(d) insulator
Answer:
(b) conductor

Question 6.
Electric charge is measured in ……………….
(a) volt
(b) coulomb
(c) ampere
(d) watt
Answer:
(b) coulomb

Question 7.
The value of charge of an electron is equal to ……………….
(a) 6.04 x 10-19 C
(b) 1.602 x 10-18 C
(c) 1.602 x 10-19 C
(d) 6.10 x 10-18 C
Answer:
(c) 1.602 x 10-19 C

Samacheer Kalvi 8th Science Solutions Term 2 Chapter 2 Electricity

Question 8.
Before using electroscope, it should be ………………..
(a) charged
(b) closed
(c) discharged
(d) cleaned
Answer:
(c) discharged

Question 9.
Lighting rods are made of ………………..
(a) copper
(b) plastic
(c) sand paper
(d) wood
Answer:
(a) Copper

Question 10.
Electricity produced on rubbing is ……………….
(a) static electricity
(b) current electricity
(c) electromagnet
(d) none
Answer:
(a) static electricity

Question 11.
The materials which allows electric current to pass through it, is called ……………….
(a) conductor
(b) insulator
(c) both a and b
(d) none of these
Answer:
(a) conductor

Question 12.
The material which does not allow electric current is called ………………..
(a) solution
(b) metal
(c) insulator
(d) electrolyte
Answer:
(c) insulator

Samacheer Kalvi 8th Science Solutions Term 2 Chapter 2 Electricity

Question 13.
All metals are ………………..
(a) conductors
(b) insulators
(c) electrolytes
(d) none
Answer:
(a) conductors

Question 14.
An electrolyte ……………….
(a) has positive charge
(b) has negative charge
(c) should be able to conduct charge without dissociating.
(d) should be able to form positive and negative ions.
Answer:
(d) should be able to form positive and negative ions

Question 15.
Most common industrial application of chemical effects of electric current is ………………..
(a) Anodizing
(b) electroplating
(c) electrolysis
(d) none
Answer:
(b) electroplating

Question 16.
The terminal which is connected to a positive terminal of a battery is called ……………….
(a) anode
(b) cathode
(c) neutral
(d) none
Answer:
(a) anode

Question 17.
Flow of per unit time is called current ………………..
(a) charge
(b) proton
(c) neutron
(d) all of these
Answer:
(a) charge

Question 18.
Liquids that conduct electricity are the solutions of ………………..
(a) acids
(b) bases
(c) salts
(d) all of these
Answer:
(d) all of these

Samacheer Kalvi 8th Science Solutions Term 2 Chapter 2 Electricity

Question 19.
A tiny particle which rotates around the nucleus of an atom is ………………..
(a) proton
(b) electron
(c) neutron
(d) both a and b
Answer:
(b) electron

Question 20.
……………….. wire is used in the filament of the bulbs.
(a) Nichrome
(b) Copper
(c) Tungsten
(d) None
Answer:
(c) Tungsten

II. Fill in the blanks

  1. Comb rubbed with hair ……………. electrons from the hair and becomes negatively charged.
  2. Electric charge is measured in ……………..
  3. Since, protons and electrons are equal in number, an atom is electrically ………………
  4. When an ebonite rod is rubbed with fur, the fur transfers …………….. to the ebonite rod.
  5. Before the discovery of electrons, it was considered that electric current is due to the flow of …………….. charges.
  6. The gold – leaf electroscope was developed by ………………
  7. …………….. is an example of discharge that takes place in clouds.
  8. During thunderstorm air is moving …………….. rapidly.
  9. Huge quantities of electricity are discharged in light flashes and temperatures of over ……………..°C or more can be reached.
  10. …………….. extreme heat will vaporize the water inside a tree, creating steam that may bum out the tree.
  11. …………….. is a device used to protect buildings from the effects of lightning .
  12. …………….. is a species offish which can give electric shocks.
  13. In series circuit, the current remains …………….. throughout the circuit.
  14. …………….. is used in extraction and purification of metals.
  15. Copper wire offers very little …………….. and does not get heated up quickly.
  16. A fuse is a strip of alloy wire which is made of lead and tin with a very low ………………
  17. The flow of ……………… per unit time is called current.

Answer:

  1. gains
  2. coulomb
  3. neutral
  4. electrons
  5. positive
  6. Abraham Bennet
  7. Lightning
  8. upward
  9. 30,000
  10. Lightning’s
  11. Lightning arrestor
  12. Electric eel
  13. same
  14. Electrolysis
  15. resistance
  16. melting point
  17. charge

III. True or False – if false give the correct statement

Question 1.
Materials which do not allow electric charges to pass through them easily are called insulator.
Answer:
True

Question 2.
Silk cloth has excess of electrons, so it becomes positively charged.
Answer:
False
Correct statement:
Silk cloth has excess of electrons, so it becomes negatively charged.

Samacheer Kalvi 8th Science Solutions Term 2 Chapter 2 Electricity

Question 3.
Electric charge is measured in coulomb.
Answer:
True.

Question 4.
Protons carry negative charge and the electrons carry positive charge.
Answer:
False.
Correct statement:
Protons carry positive charge and the electrons carry negative charge.

Question 5.
The gold – leaf electroscope was developed by Abraham Bennet.
Answer:
True

IV. Match the following

Question 1.

1.

Bulb

(a) Conductor
2. Electroplating (b)

Insulator

3.

Pure water (c) Heating effect of current
4. Salt solution (d)

Chemical effect of current

Answer:

  1. c
  2. d
  3. b
  4. a

Question 2.

1.

Insulator (a) Coulomb
2. Conductor (b)

Electric circuit

3.

Closed path (c) Copper
4. Electric charge (d)

Rubber

Answer:

  1. b
  2. c
  3. d
  4. a

Samacheer Kalvi 8th Science Solutions Term 2 Chapter 2 Electricity

Question 3.

1.

Anode (a) Conducting solution
2. Cathode (b)

Positive terminal

3.

Ions (c) Negative terminal
4. Electrolyte (d)

Positively or negatively charged

Answer:

  1. d
  2. c
  3. a
  4. b

V. Read the directions given below and answer the questions.

Question 1.
(a) If both assertion and reason are true and the reason is the correct explanation of the assertion.
(b) If both assertion and reason are true, but the reason is not the correct explanation of the assertion.
(c) If the assertion is true, but the reason is false.
(d) If the assertion is false, but the reason is true.

Question 1.
Assertion : Charges flow from higher potential to the lower potential.
Reason : Current flows mainly due to flow of electrons.
Answer:
(b) Both assertion and reason are true, but the reason is not the correct explanation of the assertion

Question 2.
Assertion : Parts of car and bicycle are made iron with chromium coating.
Reason : Chromium does not corrode and resist scratches.
Answer:
(a) Both assertion and reason are true and the reason is the correct explanation of the assertion

Samacheer Kalvi 8th Science Solutions Term 2 Chapter 2 Electricity

Question 3.
Assertion : Insulators do not allow flow of current through them.
Reason : Insulators have no free charge carrier
Answer:
(a) Both assertion and reason are true and the reason is the correct explanation of the assertion

Question 4.
Assertion : A current carrying wire should be charged.
Reason : The current in a wire is due to flow of free electrons in a definite direction.
Answer:
(d) The assertion is false, but the reason is true

Question 5.
Assertion : When both the strips of electroscope is charged with similar charge, they repel each other and become wide open.
Reason : Like charges always repel each other.
Answer:
(a) Both assertion and reason are true and the reason is the correct explanation of the assertion

VI. Answer briefly

Question 1.
Name the process which show the chemical effect of electric current?
Answer:
Electroplating.

Question 2.
What are electrodes?
Answer:
The metal rods dipped in liquids to which cells are attached are called electrodes.

Question 3.
Who discovered static electricity or lightning in clouds?
Answer:
Benjamin Franklin in 1752.

Question 4.
What are charged objects?
Answer:
The objects which acquire a small charge on rubbing are called charged objects.

Samacheer Kalvi 8th Science Solutions Term 2 Chapter 2 Electricity

Question 5.
What do you mean by earthing?
Answer:
The process of transferring of charge from a charged object to the earth is called earthing.

Question 6.
A layer of zinc coated over iron. Why?
Answer:
Layer of zinc coated over iron because zinc prevents it from rust and corrosion.

Question 7.
Name the effect of current responsible for the glow of the bulb in an electrical circuit.
Answer:
Heating effect of electric current.

Question 8.
Name a few appliances which work on the basis of heating effect of current.
Answer:
Bulb, iron, heater, electric kettles, electric cookers, electric fuse.

Question 9.
What are the essential components of an electric circuit?
Answer:
Electric cell, bulb, switch, battery and connecting wires.

Question 10.
How can you save yourselves from lightning?
Answer:

  1. We should remain in the covered area.
  2. we should not use wired telephones during lightning.

Question 11.
State some advantages electroplating.
Answer:

  1. It protects the metal from corrosion and rusting.
  2. It is used to coat desired metal on other objects.
  3. It can make more reactive metal like iron.
  4. Coating of chromium on the metal gives luster to the objects.

Question 12.
Write the differences between conductors and insulators.
Answer:
Conductors:
Materials which allow the electric current to pass through them are called conductors.
Example:
All metals, Salt water

Insulators:
Materials do not allow the current to pass through them are called insulators.
Example:
Dry wood, plastics, rubber, glass

Samacheer Kalvi 8th Science Solutions Term 2 Chapter 2 Electricity

Question 13.
What are anodes and cathodes?
Answer:

  1. In the process of electrolysis, the electrode which is connected to the positive terminal of the battery is called anode.
  2. The electrode which is connected to the negative terminal of the battery is called cathode.

Question 14.
What will be the charges on silk and glass rod when they are rubbed against each other?
Answer:

  1. When a glass rod is rubbed with silk piece, the free electrons in the glass rod are transferred to silk piece.
  2. It is because the free electrons in the glass rod are tightly bound as compared to that in silk piece.
  3. Since the glass rod looses electrons, it has a deficiency of electrons and hence acquires positive charge.
  4. But, silk piece has excess of electrons.
  5. So, it becomes negatively charged.

Question 15.
When a negatively charged glass rod is brought near another glass rod, the rod will move apart. Give reason.
Answer:
It is because both the glass rods are negatively charged. So they repel each other.

Question 16.
When an ebonite rod is rubbed with fur, the fur transfers electrons to the ebonite rod. Why?
Answer:

  1. It is because the electrons in the outermost orbit of the atoms in fur are loosely bound as compared to the ebonite rod.
  2. Ebonite rod has excess electrons which becomes negatively charged and the fur which has deficiency of electrons is positively charged.

Question 17.
List the ways in which you can charge an object.
Answer:

  1. Charging by friction
  2. Charging by induction
  3. Charging by conduction.

Question 18.
How thunder takes place?
Answer:

  1. Huge, quantities of electricity are discharged in lightning flashes and temperatures of over 30,000°C or more.
  2. This extreme heat causes the air to expand explosively fast and then they contract.
  3. This expansion and contraction create a shock wave that turns into a booming sound wave known as thunder.

Question 19.
Sometimes lighting may be seen before the thunder is heard. Why?
Answer:
It is because the distance between the clouds and the surface is very long and the speed of light is much faster than the speed of sound.

Samacheer Kalvi 8th Science Solutions Term 2 Chapter 2 Electricity

Question 20.
What do you mean by electrical Earthing?
Answer:
Electrical Earthing is defined as the process of transferring the discharge of electrical energy directly to the Earth With the help of low-resistance wire.

VII. Answer in detail

Question 1.
Explain the structure and working of gold-leaf electroscope with a diagram.
Answer:
Samacheer Kalvi 8th Science Solutions Term 2 Chapter 2 Electricity 9
Structure of I metroscope :

  1. It is made up of a glass jar.
  2. A vertical brass rod is inserted into the jar through a cork.
  3. The top of the brass rod has a horizontal brass rod or a brass disc.
  4. Two gold leaves are suspended from the brass rod inside the jar.

Working of Electroscope:

  1. When the brass disc of the electroscope is touched by a charged object, electric charge
  2. gets transferred to the gold leaf through the rod.
  3. This results in the gold leaves moving away from each other.
  4. This happens because both the leaves have similar charges.

Question 2.
Write a note on –

  1. Charging
  2. Electrical discharge.

Answer:
1. Charging:
Transfer of charge from one object to another is called charging. In case of the gold leaves charge is transferred through the brass rods.

2. Electrical Discharge:
The gold leaves resume their normal position after some time. This happens because they lose their charge. This process is called electrical discharge. The gold leaves would also be discharged when someone touches the brass rod with bare hands. In that case, the charge is transferred to the earth through the human body.

Question 3.
Explain the function of lightning arrestor with a diagram.
Answer:
Samacheer Kalvi 8th Science Solutions Term 2 Chapter 2 Electricity 10

  1. Lightning arrestor is a device used to protect buildings from the effects of lightning.
  2. Lightning conductor consists of a metallic lightning rod that remains in air at the top of the building.
  3. Major portion of the metal rod and copper cable are installed in the walls during its construction.
  4. The other end of the rod is placed deep into the soil.
  5. When lightning falls, it is attracted by the metallic rods at the top of the building.
  6. The rod provides easy route for the transfer of electric charge to the ground.
  7. In the absence of lightning arrestors, lightning will fall on the building and the building will be damaged.

Question 4.
Write a note on.

  1. Fuse
  2. Electric irons.

Answer:
1. Fuse:

  1. Fuse is a strip of alloy wire which is made up of lead and tin with a very low melting point.
  2. This can be connected to the circuit.
  3. The fuse is usually designed to take specific amount of current.
  4. When current passing through the wire exceeds the maximum limit, it gets heated up.
  5. Due to low melting point, it melts quickly disconnecting the circuit. This prevents damage to the appliances.

2. Electric irons :

  1. When current flows through the heating element, the heat energy developed is conducted to the heavy metal base, raising its temperature.
  2. This energy is then used to press clothes.

Samacheer Kalvi 8th Science Solutions Term 2 Chapter 2 Electricity

Question 5.
Distinguish between series and parallel circuit.
Answer:
Series circuit:

  1. Same amount of current flows through all the components.
  2. Voltage is different across different components.
  3. Components are arranged in a line.
  4. If one component breaks down, the whole circuit will bum out.

Parallel circuit:

  1. The current flowing through each component combines to form the current flow.
  2. Sum of the voltage through each component will be the voltage drawn from the source.
  3. Components are arranged parallel to each other.
  4. Other components will function even if one component breaks down.

VIII. Picture based Questions

Question 1.
Will the bulb glow if the end B is dipped in pure water?
Samacheer Kalvi 8th Science Solutions Term 2 Chapter 2 Electricity 11
Answer:
No, the bulb will not glow as pure water is an insulator.

Question 2.
Identify the charge on the body with a question mark.
Samacheer Kalvi 8th Science Solutions Term 2 Chapter 2 Electricity 12
Answer:
Samacheer Kalvi 8th Science Solutions Term 2 Chapter 2 Electricity 13

Question 3.
The bulb does not glow in the set up show in figure. List the possible reasons.
Samacheer Kalvi 8th Science Solutions Term 2 Chapter 2 Electricity 14
Answer:
The possible reasons are:

  1. Bulb may be fused.
  2. Cells may be used up.
  3. The liquid may be poor conductor of electricity.
  4. The connection of the circuits may be loose.

IX. Higher Order thinking skills (HOTS):

Question 1.
During the construction of a building, the lightning conductor was left hanging in the air by mistake will it be effective? Explain.
Answer:
Lighting conductor will not work. It left hanging in the air because in order to work, it must be installed properly and grounded using copper plate.

Question 2.
During lightning and thunder we should avoid standing in ground and open spaces Why?
Answer:
During lightning and thunder, we should avoid standing in ground and open spaces. You should make yourself as small as possible by squating. It is however safe to stay inside a car because the car acts as a shield and protects us from the electric field generated by the storm.

Samacheer Kalvi 8th Science Solutions Term 2 Chapter 2 Electricity

Question 3.
You might have observed on a dry day that when you touch the screen of a television you get a slight shock. Why does it happen?
Answer:
It happens because the television screen is charged and have static charges and when we touch with our hands which are uncharged, the charges attract our hands and transfer through our hands and we get a small shock.

X. Solve the following crossword with the help of the given clues.

Clue:
Across :
1. Ions having a positive charge formed by the loss of electrons.
2. Chemical compound which conducts electricity when in aqueous state.
5. Atoms that have an electric charge.
7. A piece of metal through which an electric current enters or leaves in a liquid or gas.

Down :
3. A process in which a thin film of metal is deposited on another metal with the help of electricity.
4. A process in which a chemical change especially decomposition of a chemical compound is brought about by passing an electric current through a solution.
6. Ions having a negative charge formed by the gain of electrons.
8. The negative electrode is an electrolytic cell, toward which positively charged particles are attracted.
Answer:
Samacheer Kalvi 8th Science Solutions Term 2 Chapter 2 Electricity 15

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Samacheer Kalvi 8th Maths Solutions Term 2 Chapter 4 Information Processing Ex 4.3

Students can Download Maths Chapter 4 Information Processing Ex 4.3 Questions and Answers, Notes Pdf, Samacheer Kalvi 8th Maths Book Solutions Guide Pdf helps you to revise the complete Tamilnadu State Board New Syllabus and score more marks in your examinations.

Tamilnadu Samacheer Kalvi 8th Maths Solutions Term 2 Chapter 4 Information Processing Ex 4.3

Question 1.
Choose the correct answers:

Question (i)
In questions A and B, there are four groups of letters in each set. Three of these sets are like in some way while one is different. Find the one which is different.
A. (a) C R D T (b) A P B Q (c) E U F V (d) G W H X
B. (a) H K N Q (b) I L O R (c) J M P S (d) A D G J
Answer:
A. (a) C R D T (b) A P B Q (c) E U F V (d) G W H X
Hint:
The four groups of letters are
CRDT APBQ EUFV GWHX
The above can be written as
Samacheer Kalvi 8th Maths Solutions Term 2 Chapter 4 Information Processing Ex 4.3 1
We find that when we take 1st & 3rd letter & 2nd & 4th letter as 2 pairs, the 3rd letter is the next letter alphabetically to the 1st letter.
Similarly the 4th letter is alphabetically the next letter of the 2nd letter.
i.e CD, AB, EF, GH & PQ, UV, WX
Only in CRDT, we have T instead of ‘S’. So,
Answer:
in CRDT ⇒ Option (a)

B. The four groups of letters are
HKNQ ILOR JMPS ADGI
If we notice, we find that 2 letters are missing in the sequence, ie.
HIJKLMNOPQ IJKLMNOPQR
LKLMNOPQRS ABCDEFGHI
We find that only in ADGI, the difference is only one letter between G & I.
Hence it is the odd one out.

Samacheer Kalvi 8th Maths Solutions Term 2 Chapter 4 Information Processing Ex 4.3

Question (ii)
A group of letters are given. A numerical code has been given to each letter. These letters have to be unscrambled into a meaningful word. Find out the code for the word so formed from the 4 answers given.
Samacheer Kalvi 8th Maths Solutions Term 2 Chapter 4 Information Processing Ex 4.3 2
(a) 2 3 4 1 5 6
(b) 5 6 3 4 2 1
(c) 6 1 3 5 2 4
(d) 4 2 1 3 5 6
Answer:
(b) 5 6 3 4 2 1
hint:
Given code is
Samacheer Kalvi 8th Maths Solutions Term 2 Chapter 4 Information Processing Ex 4.3 2
Option (a) is 234156. When we substitute number for each letter from code, we get,
Samacheer Kalvi 8th Maths Solutions Term 2 Chapter 4 Information Processing Ex 4.3 3
Option (b) is 563421, similarly, we get 5 6 3 4 2 1
Samacheer Kalvi 8th Maths Solutions Term 2 Chapter 4 Information Processing Ex 4.3 4
Option (c) is
Samacheer Kalvi 8th Maths Solutions Term 2 Chapter 4 Information Processing Ex 4.3 5
Option (d) is
Samacheer Kalvi 8th Maths Solutions Term 2 Chapter 4 Information Processing Ex 4.3 6
So, only in option b, we get a meaningful word, i.e PENCIL.
Hence, answer is Option (b)

Question (iii)
In questions I and II, there are based on code language. Find the correct answer from the four alternatives given. A
C In a certain code, ‘M E D I C I N E’ is coded as ‘COMPUTER’ written in the same code?
(a) C N P R V U F Q
(b) C M N Q T U D R
(c) R F U V Q N P C
(d) R N V F T U D Q
Answer:
(C) R F U V Q N P C
Hint:
It is given that in a certain code M E D I C I N E is coded as E O J D J E F M When we observe the word & the code, we find that, there is a pattern.
Samacheer Kalvi 8th Maths Solutions Term 2 Chapter 4 Information Processing Ex 4.3 7
[to understand, see the matching shapes]
To get the code from the word, we follow the below steps
1. Samacheer Kalvi 8th Maths Solutions Term 2 Chapter 4 Information Processing Ex 4.3 8
swap 1st & last letters, so we get
E [ E D I C I N ] M
2. For the middle letters, replace the letters with their alphabetically next letters, so we get
Samacheer Kalvi 8th Maths Solutions Term 2 Chapter 4 Information Processing Ex 4.3 9
3. Now we have to reverse the order of the middle letters in the bracket, so we get
E[O J D J E F]M = E O J D J E F M
Thus we get the code.
So similarly, we have to follow the 3 steps to get code, therefore:
for
Samacheer Kalvi 8th Maths Solutions Term 2 Chapter 4 Information Processing Ex 4.3 10
Step 1: Swap 1 st & last letters, so we get
R [O M P U T E ]C
Step 2: For the middle letters, replace the letters with alphabetically next letters, so we get
R [P N Q V U F] C
Step 3: Reverse the word of letters in the bracket to we get
R [F U V Q N P] C
∴ Ans is R F U V Q N P C ⇒ Option C

Question (iv)
If the word ‘PHONE’ is coded as ‘S K R Q H’, how will ‘R A D I O’ be coded?
(a) S C G N H
(b) V R G N G
(c) U D G L R
(d) S D H K Q
Answer:
(C) U D G L R
hint:
If PHONE is coded as S K R Q H
Find that code for R A D I O
Samacheer Kalvi 8th Maths Solutions Term 2 Chapter 4 Information Processing Ex 4.3 11
We find that we get the code, by 3rd letter alphabetically so, from P, skipping Q & R, we get S.
Similarly, from H, skipping I & J, we get K
Like wise for R A D I O, skipping the 2 alphabets
From R, skip S & T → U
From A, skip B & C → D
Samacheer Kalvi 8th Maths Solutions Term 2 Chapter 4 Information Processing Ex 4.3 12
From D skip E & F → G
From I skip J & K → L
From O skip P & Q → R
Answer:
is U D G L R ⇒ Option c

Samacheer Kalvi 8th Maths Solutions Term 2 Chapter 4 Information Processing Ex 4.3

Question 2.
Fill in the blanks (Use Atbash Cipher that is given in code 3)
For this question, we need to use Atbash cipher. For Atbash cipher, first we write the alphabets from A to Z and then in reverse from Z to A below that.
ABCDEFGHIJKLMNOPQRSTUVWXYZ
ZYXWVUTSRQPONMLKJIHGFEDCBA

Question (i)
G Z N R O = …………
Answer:
TAMIL
Hint:
Now to solve, we look up the corresponding letter from the table to replace in code to get the actual word.
So, for G Z N R O, from table,
for G, it is T
for Z, It is A
for N, it is M
for R, it is I
for O, it is L
So , the actual word is TAMIL

Question (ii)
V M T O R H S = ………
Answer:
ENGLISH
Hint:
V M T O R H S
To solve, we look up the corresponding letter from table to replace in code to get the actual word.
For V, it is E
for M, it is N
for T, it is G
for O, it is L
for R, it is I
for H, it is S
for S, it is H
Therefore we get E N G L I S H = ENGLISH

Question (iii)
N Z G S V N Z G R X H = ………
Answer:
MATHEMATICS
Hint:
Similarly as above for
Samacheer Kalvi 8th Maths Solutions Term 2 Chapter 4 Information Processing Ex 4.3 13

Question (v)
H X R V M X V = ………..
Answer:
SCIENCE
Hint:
Samacheer Kalvi 8th Maths Solutions Term 2 Chapter 4 Information Processing Ex 4.3 14

Samacheer Kalvi 8th Maths Solutions Term 2 Chapter 4 Information Processing Ex 4.3

Question (v)
HLXRZO HXRVMX V = ………..
Answer:
SOCIAL SCIENCE
Hint:
Samacheer Kalvi 8th Maths Solutions Term 2 Chapter 4 Information Processing Ex 4.3 15

Question 3.
Match the following (a = 00 ……… Z = 25)
Samacheer Kalvi 8th Maths Solutions Term 2 Chapter 4 Information Processing Ex 4.3 16
Answer:
(i) – c
(ii) – d
(iii) – a
(iv) – e
(v) – b
Solution:
Given that the code is
Samacheer Kalvi 8th Maths Solutions Term 2 Chapter 4 Information Processing Ex 4.3 17
Hint:
(i) Mathematics is
Samacheer Kalvi 8th Maths Solutions Term 2 Chapter 4 Information Processing Ex 4.3 18
So matching option is c

(ii) addition is
Samacheer Kalvi 8th Maths Solutions Term 2 Chapter 4 Information Processing Ex 4.3 19
Matching option is d

(iii) Subtraction is
Samacheer Kalvi 8th Maths Solutions Term 2 Chapter 4 Information Processing Ex 4.3 20
Matching option is a

(iv) multiplication is
Samacheer Kalvi 8th Maths Solutions Term 2 Chapter 4 Information Processing Ex 4.3 21
Matching option is e, however instead of 25, it should be 08.

(v) division is
Samacheer Kalvi 8th Maths Solutions Term 2 Chapter 4 Information Processing Ex 4.3 22
Matching option is b

Question 4.
Frame Additive cipher table (key = 4).
Solution:
Step 1 : write all alphabets
Step 2 : Assign numbers to each alphabet starting from 00 till 25.
Step 3 : add key value (here it is 4) to the numbers assigned in step 2 to form cipher table
Samacheer Kalvi 8th Maths Solutions Term 2 Chapter 4 Information Processing Ex 4.3 23

Question 5.
A message like “Good Morning” written in reverse would instead be “Doog Gninrom”. In the same way decode the sentence given below: “Ot dnatsrednu taht scitamehtam nac eb decneirepxe erehwreve ni erutan dna laer efil.”
Solution:
Given that good morning written in reverse is doog gninrom.
We have to decode the below by reversing, so,
Ot dnatsrednu taht scitamehtam nac eb decneirepxe erehwreve ni erutan dna laer efil.
Answer:
to understand that mathematics can be experienced everywhere in nature and real life.

Samacheer Kalvi 8th Maths Solutions Term 2 Chapter 4 Information Processing Ex 4.3

Question 6.
Decode the given Pigpen Cipher text and compare your answer to get the Activity 3 result.
Samacheer Kalvi 8th Maths Solutions Term 2 Chapter 4 Information Processing Ex 4.3 24
(i) The room number in which the treasure took place
Samacheer Kalvi 8th Maths Solutions Term 2 Chapter 4 Information Processing Ex 4.3 4234
(ii) Place of the treasure
Samacheer Kalvi 8th Maths Solutions Term 2 Chapter 4 Information Processing Ex 4.3 54
(iii) The name of the treasure
Samacheer Kalvi 8th Maths Solutions Term 2 Chapter 4 Information Processing Ex 4.3 546
Solution:
(i) The room in which the treasure took place = 28
(ii) The place of treasure = Chair
(iii) Identity of treasure = Gift voucher.

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