NCERT QUESTIONS:
Q.1. : Explain why some fibres are called synthetic
Q.2: Mark the correct answer :
Rayon is different from synthetic fibres because
(a) It has a silk-like appearance
(b) It is obtained from wood pulp
(c) Its fibres can also be woven like those of natural fibre.
Q.3: Fill in the blanks:
(a) Synthetic fibres are also called ___________ or ____________ fibres.
(b) Synthetic fibres are synthesised from raw material called __________.
(c) Like synthetic fibres, plastic is also a ___________ .
Q.4: Give examples which indicate that nylon fibres are very strong.
Q.5: Explain why plastic containers are favoured for storing food?
Q.6: Explain the differences between thermoplastics and themosetting plastics.
Q.7: (a) Explain why the following is made of themosetting plastics? - Saucepan handles
Q.7: (b) Explain why the following is made of themosetting plastics? - Electric plugs/ switches/plug boards
Q.8: Categorise the materials of the following products into “can be recycled” and “cannot be recycled”.
Telephone instruments, plastic toys, cooker handles, carry bags, ball point pens, plastic bowls, plastic covering on electrical wires, plastic chairs, electrical switches.
Q.9: Rane wants to buy shirts for summer. Should he buy cotton shirts or shirts made from synthetic material? Advise Rane, giving your reason.
Q.10: Give examples to show that plastics are non-corrosive in nature.
Q.11: Should the handle and bristles of a tooth brush be made of the same material? Explain your answer.
Q.12: “Avoid plastics as far as possible” comment on this advice.
Q.13: Match the terms of column A correctly with the phrases given in column B.
Q.14: Manufacturing synthetic fibres is actually helping conservation of forests. Comment.
Q.15: Describe an activity to show that thermoplastic is a poor conductor of electricity.
IMPORTANT QUESTIONS:
Q.1: What is meant by biodegradable and non-biodegradable materials?
Q. 2: What is the meaning of 4Rs ?
Q.3: Why are plastics considered a threat to our environment?
Q.4: What is meant by synthetic fibres?
Q.5: We prefer nylon ropes instead of cotton or jute ropes for rock climbing. Why?
Q.6: We prefer to buy an acrylic blanket instead of wool blanket. Why?
Q.7: Rayon is called an artificial silk. Why?
Q.8: How plastics are used in health care industry?
Q.9 : We should not wear synthetic clothes while working in the kitchen. Why?
Q.10: Plastics are poor conductors of heat and electricity. Give examples.
Q.11 : A bucket made of plastic does not rust like a bucket made up of iron. Why?
Q.12: Name some natural fibres.
Q.13: A synthetic fibre which looks like silk is obtained by chemical treatment of wood pulp. It is known as artificial silk. What is its common name?
Q.14. Name some artificial fibres.
Q.15: Cotton is a natural polymer. What is its chemical name.
Q.16: Terrycot is made by mixing two types of fibres. Write the names of the fibres.
Q.17: What is PET?
Q.18: Name the first fully synthetic fibre.
Q.19: Which raw material is used for making synthetic fibres?
Q..20: Name any two thermoplastics.
Q.21: Why is polyester not suitable for summer wear?
Q.22: Name the polymer used in making non-stick cookwares.
Q.23: Which is the most suitable material for preparation of handles of cooking utensils?
Q.24: Which plastic is used for making crockery?
Q.25: Which fibre is similar to wool or often used as a substitute to wool?
Q.26: Whether most of the plastics are biodegradable?
