NCERT Class 8 Science Chapter 3 Synthetic Fibres and Plastics Extra Questions and Answers
Class 8 Science Chapter 3 Extra Questions and Answers – Synthetic Fibres and Plastics. Here in this Page Class VII Students can Learn Extra Questions & Answer 3rd Chapter Science fully Inside.
We Provided Here Synthetic Fibres and Plastics Science Chapter 3 Long Answer Type Question, Very Short Type Questions (VSA) / MCQ Type Questions, Short Type Questions (SA).
Class 8 Science Chapter 3 Extra Question with Answer – Synthetic Fibres and Plastics
Science Chapter 3 Synthetic Fibres and Plastics Class 8 Inside 5 Marks, 3 marks, 2 Marks & And 1 Marks Important Questions and Answers.
1) Fill in the blanks:
a) ____ Polyester is used for making bottles, wire. (PET)
b) ____ is a mixture of polyester and cotton. (Polycot)
c) ____ is an example of a plastic. (Polythene)
d) ____ is used for floor tiles. (Melamine)
e) All the synthetic fibers are prepared by using ____ chemicals. (Petrochemicals)
2) Multiple choice questions:
a) ____ is a mixture of polyester and wool?
a) Polycot b) Poly wool
Ans. b) Poly wool
b) ____ is a special plastic on which oil and water do not stick?
a) Melamine b) Teflon c) Polythene
Ans. b) Teflon
c) ____synthetic fiber is used to make sweaters, blankets?
a) Rayon b) Acrylic c) Nylon
Ans. b) Acrylic
d) Synthetic fiber and plastics, are made of very large units called ____?
a) Rayon b) Polymer c) Nylon
Ans. b) Polymer
e) ____ is a fire-proof plastic?
a) Polythene b) PVC c) Melamine
Ans. c) Melamine
3) Answer the following questions:
a) What is thermoplastics? Give an example.
Ans. The plastics which get deformed easily by heating and can be bent easily are known as thermoplastics.
Example – Polythene.
b) What is thermosetting plastics? Give an example.
Ans. The plastics which when molded once, cannot be softened by heating, are called thermosetting plastics.
Example – Bakelite.
c) What is biodegradable? Give an example.
Ans. A material which gets decomposed through natural processes, is called biodegradable.
Example – Metal cans.
d) What is non-biodegradable? Give an example.
Ans. A material which is not easily decomposed by natural processes, is called Non-biodegradable.
Example – Plastic bags.
e) Write the characteristic properties of plastics.
Ans. The characteristic properties of plastics are,
i.) Plastic is non-reactive.
ii.) Plastic is light, strong and durable.
iii.) Plastics are poor conductor.
4) Mark your answer as per the code provide below:
a) A: Bakelite is used for making electrical switches.
R: Bakelite is a thermosetting plastic.
I.) Both A and R are true and R is the correct explanation of A.
II.) Both A and R are true but R is not the correct explanation of A.
III.) A is true but R is false.
IV.) A is false but R is true.
V.) Both A and R are false.
Ans. I. Both A and R are true and R is the correct explanation of A.
b) A: Plastic bottles are biodegradable.
R: Plastic bottles are not easily decomposed by natural processes.
I.) Both A and R are true and R is the correct explanation of A.
II.) Both A and R are true but R is not the correct explanation of A.
III.) A is true but R is false.
IV.) A is false but R is true.
V.) Both A and R are false.
Ans. IV. A is false and R is true.
5) There are some plastics which when molded once, cannot be softened by heating. These are called thermosetting plastics. Examples are Bakelite and Melamine. Bakelite is a poor conductor of heat and electricity. It is used for making electrical switches, handles of various utensils, etc. Melamine is a versatile material. It resists fire and can tolerate heat better than other plastics. It is used for making floor tiles, kitchenware and fabrics which resists fire.
a) Bakelite is a _____ conductor of heat and electricity. (Poor)
b) _____ is used for making handles of various utensils. (Bakelite)
c) Why the uniforms of firemen have coating of melamine?
Ans. Melamine is a versatile material. It resists fire and can tolerate heat better than other plastics. So, the uniforms of firemen have coating of melamine to make them flame resistant.
More Extra Questions and Answers
Q.1) Underline the correct answer
1)Nylon is a natural /man made fibre
2)Wood is a Biodegradable/ non biodegradable material
3 ) Plastic are good/ bad conductor of electricity
4) Polythene is used for making plastic /polythene bags
5 ) Plastic is reactive /non reactive.
Q.2) Say whether the following statements are true or false.
1 ) PET (polyethylene terephthalate) is a form of polyester.
Ans :True
2 )Terylene is not a polyester.
Ans :False
3) The waste created by plastic is eco friendly
Ans :False
Q.3) Differentiate between
1.) Biodegradable and non biodegradable waste
| Biodegradable Waste |
Non biodegradable waste |
| 1) Material which gets decomposed through natural process is called biodegradable waste. | 1) Material which do not get decomposed through natural process is called non biodegradable waste. |
| 2) Example – woolen cloth | 2) Example: plastic bag |
Q.4) Answer the following
1) What is 5R principal ?
Ans : 5R principle is -Reduce , Reuse , Recycle ,Recover ,Refuse.
2 )Name any 2 articles made of nylon.
Ans : Socks ,tent, belt ,curtains
3 ) What is thermoplastics ?
Ans :Plastic which get deformed easily on hitting and can be bent easily is called thermoplastic.
Q.5 )Explain
1) Plastic is used as a good option for storage
Ans :Plastic do not react with air and water thus the goods stored in plastic container does not get affected with the external agents. hence plastic is used as a good option for storage.
2) Describe any 2 characteristics of plastic
Ans :i) non reactive plastic do not react with moisture air etc.they do not get corroded easily.
ii) plastic are poor conductor of electricity as they are poor conductor of electricity we can see that electric wires have plastic covering.
Q.6) classify the below as biodegradable and non biodegradable
| Type | Biodegradable/Non biodegradable |
| 1) Vegetable leftover | Biodegradable |
| 2) Paper | Non biodegradable |
| 3) Cotton cloth | Non biodegradable |
| 4) Wood | Non biodegradable |
| 5) Woolen cloth | Non biodegradable |
| 6) Aluminium | Non biodegradable |
| 7) Metal can | Non biodegradable |
Q.7) Describe in your own words on the below statement.
1.) Plastic is harmful for nature.
Ans : a) Plastic release harmful chemical nature when burned.
b) It dumped ground takes many years to decompose.
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