true/false
1.semi synthetic fibre prepared by chemical synthesis from natural materials
2. terylene and dacron is common varieties of acrylic fibres.
Answers
Answer:
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NCERT Exemplar Class 8 Science Chapter 3 Synthetic Fibres and Plastics
April 25, 2019 by Bhagya
NCERT Exemplar Class 8 Science Chapter 3 Synthetic Fibres and Plasticst are part of NCERT Exemplar Class 8 Science. Here we have given NCERT Exemplar Class 8 Science Chapter 3 Synthetic Fibres and Plastics.
NCERT Exemplar Class 8 Science Chapter 3 Synthetic Fibres and Plastics
Multiple Choice Questions
Question. 1 Pick the synthetic fibre out of the following.
(a) Cotton (b) Nylon (c)Jute (d)Wool
Answer. (b) Nylon Is a synthetic fibre. It is made without using any natural raw material. Cotton, jute and wool are natural fibres.
Question. 2 Which of the following is a source of rayon?
(a) Wool (b) PET (c) Wood pulp (d) Silk
Answer. (c) Wool pulp
Rayon is obtained by the chemical treatment of wool pulp (which contains cellulose).
Question. 3 Polycot is obtained by mixing
(a) nylon and wool (b) polyester and wool
(c) nylon and cotton (d) polyester and cotton
Answer. (d) Polycot is obtained by mixing polyester and cotton.
Polycot = polyester + cotton
Question. 4 Which is a thermosetting plastic?
(a) Melamine (b) Polythene –
(c) PVC (d) Nylon
Answer. (a) Melamine is a thermosetting plastic which when moulded once, cannot be softened by heating.
Question. 5 The material similar to silk in appearance is
(a) nylon (b) rayon
(c) polyester (d) terylene
Answer. (b) Rayon resembles silk in appearance, therefore, rayon is also called artificial silk.
Question. 6 The most suitable material for the preparation of handles of cooking utensils is (a) polythene (b) PVC
(c) nylon (d) bakelite
Answer. (d) Bakelite is used for making the handles of various cooking utensils because it is a poor conductor of heat and does not become soft on getting heated.