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Ncert Exemplar Solutions Class 8 Science Synthetic Fibres and Plastics
Welcome to NCTB Solutions. Here with this post we are going to help 8th class students for the Solutions of NCERT Exemplar Class 8 Science Book, Unit 3, Synthetic Fibres and Plastics. Here students can easily find step by step solutions of all the problems for Synthetic Fibres and Plastics, Also here our Science teacher’s are solved all the questions with easily understandable language with proper guidance so that all the students can understand easily.
Synthetic Fibres and Plastics Solution :
Multiple Choice Questions :
Question no – (1)
Pick the synthetic fibre out of the following?
Answer :
The correct answer is option – (b) Nylon
Here, Nylon is the synthetic fibre.
Question no – (2)
Which of the following is a source of rayon?
Answer :
The appropriate answer is option – (c)
Wood pulp is a source of rayon.
Question no – (3)
Polycot is obtained by mixing
Answer :
The answer is alternative – (d)
Polycot is obtained by mixing polyester and cotton.
Question no – (4)
Which is a thermosetting plastic?
Answer :
The answer is option – (a)
Melamine is a thermosetting plastic.
Question no – (5)
The material similar to silk in appearance is
Answer :
The correct answer is option – (b)
The material similar to silk in appearance is Rayon.
Question no – (6)
The most suitable material for the preparation of handles of cooking utensils is
Answer :
The appropriate answer is option – (d)
The most suitable material for the preparation of handles of cooking utensils is Bakelite.
Question no – (7)
Which of the following is not a common property of plastics?
Answer :
The appropriate option is – (d)
Good conductor of electricity is not a common property of plastics.
Question no – (8)
Which of the following represents the correct match for items in
Answer :
The correct option is – (b) I-(iii), II-(i), III-(ii)
Question no – (9)
Which of the following groups contain all synthetic substances?
Answer :
The correct option is – (c)
PVC, Polythene, Bakelite – This group contain all synthetic substances.
Question no – (10)
The material which is commonly used for making kitchen containers is
Answer :
The correct option is – (d) PET
For making kitchen containers the commonly used material is PET.
Very Short Answer Questions :
Question no – (11)
Answer :
Cotton is a natural polymer and it’s chemical name is Cellulose.
Question no – (12)
Answer :
Rayon is the common name of this synthetic fiber which looks like silk and is obtained from chemical treatment of wood pulp.
Question no – (13)
Answer :
Terrycot is made by mixing terylene and cotton fibres together.
Question no – (14)
Answer :
Plastics are available in all shape and sizes because the plastic polymers are arranged in different manner, like some of them are linear and some are criss crossed.
Question no – (15)
Answer :
It is advised to not use plastics as far as possible because plastics are non-biodegradable and it takes thousands of years to decompose and is vey harmful for the environment.
Question no – (16)
Answer :
It is advised not to burn plastic and synthetic fabrics because the burning of these materials produces a lot of toxic gases that causes air pollution.
Question no – (18)
Answer :
A plastic bucket does not rust like a iron bucket as plastic bucket are non reactive that is they don’t react with the atmospheric water and oxygen to form rust just like an iron bucket.
Short Answer Questions :
Question no – (19)
Answer :
Rohit selected the nylon rope because he knows that nylons are much stronger, lighter and are more elastic than jute or cotton ropes. This would ensure him a safe and thrilling adventure.
Question no – (20)
Answer :
She preferred to buy an acrylic blanket because she knows that acrylic blankets are much cheaper, are available in variety of colors and are relatively much durable than a natural fiber like wool.
Question no – (22)
Answer :
(a) A polymer is a chain of many small units joined together which are called Monomers.
(b) The synthetic fibres are also known as Man-made fibres.
(c) The first fully synthetic fibre was Nylon
(d) A fibre similar to wool is Acrylic
(e) A plastic used for making crockery is Melamine.
Question no – (23)
Answer :
(a) Nylon → Parachutes.
(b) PET → Polyester.
(c) Rayon → Artificial silk.
(d) Thermosetting plastic → Electric wires.
(e) Teflon → Non stick coating.
Question no – (24)
Answer :
(a) anory → Rayon
(b) lopmery → Polymer
(c) relyteen → Terylene
(d) laspict → Plastic
(e) yespolter → Polyester
(f) felton → Teflon
Long Answer Questions :
Question no – (25)
Answer :
(i) The fabric terywool is obtained by mixing terylene and wool.
This statement is True.
(ii) Synthetic fibres do not melt on heating.
This statement is False.
Reason : Synthetic fibers do melt on heating.
(iii) It is risky to wear synthetic clothes while working in the kitchen.
This statement is True
(iv) Most of the plastics are biodegradable.
This statement is False.
Reason : Most of the plastics are non biodegradable.
Question no – (26)
Answer :
Synthetic fibers such as nylon, acrylic, polyester and plastics are of much importance to us. Nylons are very strong so they are used to make parachutes wires, seatbelts etc. Acrylics are very cheap and colorful so they are used to make sweater and shawls. Polyester are easy to wash and don’t wrinkle easily so they are used to make dresses. Plastic are used in variety of places such as making switch wires, kitchenware’s, floor tiles and various of another handles.
Question no – (27)
Answer :
Even tough plastic is very useful for us it is advised to restrict the use of plastics because since plastic are non biodegradable and when they are left open in the ground they causes serious land pollution. Moreover the burning of these plastic releases harmful gases that decreases the air quality of the surrounding air. Reusing or recycling the plastic materials to make another products instead of throwing it away is one way of limiting it’s consumption. We could also limit our dependence on plastics by finding another alternative of plastic.
Other Chapter Solutions :
👉 Crop Production and Management
👉 Microorganisms : Friend and Foe
👉 Materials : Metals and Non-Metals
👉 Conservation of Plants and Animals
👉 Cell-Structure and Functions
👉 Reaching the Age of Adolescence
👉 Force
👉 Friction
👉 Sound
👉 Chemical Effects of Electric Current
👉 Light
