Olympiad Test: Synthetic Fibres And Plastics


20 Questions MCQ Test Science Class 8 | Olympiad Test: Synthetic Fibres And Plastics


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This mock test of Olympiad Test: Synthetic Fibres And Plastics for Class 8 helps you for every Class 8 entrance exam. This contains 20 Multiple Choice Questions for Class 8 Olympiad Test: Synthetic Fibres And Plastics (mcq) to study with solutions a complete question bank. The solved questions answers in this Olympiad Test: Synthetic Fibres And Plastics quiz give you a good mix of easy questions and tough questions. Class 8 students definitely take this Olympiad Test: Synthetic Fibres And Plastics exercise for a better result in the exam. You can find other Olympiad Test: Synthetic Fibres And Plastics extra questions, long questions & short questions for Class 8 on EduRev as well by searching above.
QUESTION: 1

Coir fiber is obtained from

Solution: COIR is a versatile natural fibre extracted from mesocarp tissue or husk of the coconut fruit. The husk contains 20% to 30% fibre of varying lengths. After grinding the husk, the long fibres are removed and used for various industrial purposes, such as rope and mat making.

QUESTION: 2

The world's first fully synthetic plastic was:

Solution: The world's first fully synthetic plastic was bakelite, invented in New York in 1907 by Leo Baekeland who coined the term 'plastics'. Bakelite is made from carbolic acid (phenol) and formaldehyde and is referred to as a phenolic resin. Bakelite was the first thermosetting plastic.

QUESTION: 3

Figure(ii) shows an arrangement of units that make up plastics. Name the arrangement:

Solution: Cross-linked polymers, on the other hand, are those in which chemical bonds are formed between adjacent polymer chains, so that a network structure forms.

QUESTION: 4

Which of the following are natural fibres?

Solution: Natural fibres can be classified according to their origin. The vegetable, or cellulose-based, the class includes such important fibres as cotton, flax, and jute. The animal, or protein-base, fibres include wool, mohair, and silk. An important fibre in the mineral class is asbestos.

QUESTION: 5

__________is not a natural fiber.

Solution: Rayon is a regenerated cellulose fiber that is made from natural sources of cellulose, such as wood and related agricultural products. It has the same molecular structure as cellulose. Viscose can mean A viscous solution of cellulose. A synonym of rayon.

QUESTION: 6

_________ is the first fully synthetic fibre.

Solution: Nylon was the first fully synthetic fibre made in 1931, without using any natural raw material. It was prepared from chemicals. Nylon fibres are strong, lustrous, elastic, and used for making stockings, car belts, parachutes, ropes, etc.

QUESTION: 7

A polymer is a large molecule composed of many repeated units. What is a polyester composed of?

Solution: Polyester (Poly+ester) is a category of polymers, made up of the repeating units of a type of chemical called an ester. Polyester fibres are strong, resistant to stretching and shrinking. They dry quickly, are wrinkle-resistant and can be easily washed.

QUESTION: 8

Which of the following material is a mixture of two fibres?

Solution: Polywool is a blend of polyester and wool. The blend is designed to afford the advantages of both the wool and polyester fibres in one fabric, such as wrinkle resistance, increased absorbancy, increased strength, etc.

QUESTION: 9

Which of the following fibres is used for making parachutes?

Solution: Nylon threads are strong, elastic, and lightweight. A nylon rope is actually stronger than a steel wire. Hence, it is preferred for making parachutes. Harness straps, suspension lines, tents, sleeping bags, sails, rope, tennis strings, fishing poles, and lines, etc. are also made from nylon fibers because of their strength.

QUESTION: 10

One of the advantages of nylon over rayon is that nylon:

Solution: High elasticity and no wrinkling are the major advantages of nylon over rayon. Hence, though both are suitable for the textile industry, nylon is more popular in making dresses and uniforms than rayon.

QUESTION: 11

Identify the type of plastic that can best be used to make electrical switches.

Solution: Bakelite is a thermosetting plastic, which means it retains its shape even at high temperatures. Whereas, the others mentioned are thermoplastics that can be moulded on heating. Also, bakelite is a poor conductor of electricity, hence, it protects us from getting electric shocks. This is the reason, bakelite is used for making electrical switches, handles of various utensils, etc.

QUESTION: 12

Modern non-stick cookware and the flat end of an electric iron has a coating of a polymer. Identify the name of the polymer.

Solution: A non-stick surface can reduce the ability of other materials to stick on it. These surfaces are coated with a synthetic polymer called teflon. Non-stick cookware and the flat end of an electric iron are coated with teflon.

QUESTION: 13

Which of the following is a natural fibre obtained from plants?

Solution: Cotton is a natural fiber which is obtained from cotton plants. These are the epidermal hairs on the seeds of the crop plants. The fiber is composed of the natural cellulosic material which is used for the production of the cotton ropes from fibres and clothes.

QUESTION: 14

Which one of the following is thermosetting plastic?

Solution: Thermosetting plastics are those plastics which once molded, cannot be softened by heating. Two examples are

i) Bakelite: Used for making electrical switches, handles of various utensils.

ii) Melamine: Used for making floor tiles, kitchenware, and fabrics that can resist heat.

QUESTION: 15

Terylene is a popular form of

Solution: Terylene fabric is a synthetic polyester fibre based on terephthalic acid. It is characterized by weightlessness and crease resistance. Terylene is mostly used for clothing, ropes, sheets, sails, and many others. The name 'terylene fabric' may also refer to any large class of synthetic fabric.

QUESTION: 16

Petrochemicals are

Solution: Petrochemicals are materials obtained from the refining of petroleum. These petrochemicals are used as raw material for manufacturing synthetic fibres.

QUESTION: 17

Pickles are stored in plastic bottles mainly because they are:

Solution: Pickles have an acid (vinegar) in them. Plastics do not react with the chemicals present in the pickle and do not corrode easily. Hence, it is safe to keep pickles in plastic or glass containers to avoid reaction between the acid and the container.

QUESTION: 18

Polyethylene terephthalate belongs to which class of synthetic polymer?

Solution: Polyethylene terephthalate commonly abbreviated PET or PETE is a member of the polyester family of polymers. Polyester is a category of polymers, in which ester is the repeating unit.

QUESTION: 19

Which of the following is non-biodegradable?

Solution: The plastics are the non-biodegradable wastes because they are synthetic polymers which cannot be acted upon by the microbes. They cannot be degraded by the decomposition activity of the bacteria and fungi. The cotton, paper and leftover food are degradable.

QUESTION: 20

Which term is used for polymers made up of a large number of glucose units?

Solution: Cellulose fibers can be obtained from the bark, wood, or leaves of plants, or from plant-based material. Cotton is a polymer of cellulose. It is made up of a large number of glucose units.