Test: Synthetic Fibres And Plastics (Easy)


15 Questions MCQ Test Science Class 8 | Test: Synthetic Fibres And Plastics (Easy)


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This mock test of Test: Synthetic Fibres And Plastics (Easy) for Class 8 helps you for every Class 8 entrance exam. This contains 15 Multiple Choice Questions for Class 8 Test: Synthetic Fibres And Plastics (Easy) (mcq) to study with solutions a complete question bank. The solved questions answers in this Test: Synthetic Fibres And Plastics (Easy) quiz give you a good mix of easy questions and tough questions. Class 8 students definitely take this Test: Synthetic Fibres And Plastics (Easy) exercise for a better result in the exam. You can find other Test: Synthetic Fibres And Plastics (Easy) extra questions, long questions & short questions for Class 8 on EduRev as well by searching above.
QUESTION: 1

Which of the following materials take the longest to degenerate?

Solution: Plastic bags, because they are complex polymers of long-chain hydrocarbons. It is non-biodegradable. Plastic bags do not break down naturally. When we dispose of them in a garbage pile, the air, moisture, climate, or soil cannot break them down naturally to be dissolved with the surrounding land.

However natural waste and products made from nature break down easily when they are disposed of as waste.

QUESTION: 2

Assertion

Rayon is a semi-synthetic polymer and is taken as a better choice than cotton fabric.

Reason

Mechanical and aesthetic properties of cellulose can be improved by acetylation.

Solution: The strength of cellulose is improved by acetylation and then for making packing material. Rayon, which is a semi-synthetic polymer, has superior properties to natural cotton.

Both assertion and reason are correct and the reason is the correct explanation for the assertion.

QUESTION: 3

Polycot is a mixture of:

Solution: C, Polycot is a mixture of polyester and cotton. It is prepared in the laboratory. Cotton is obtained from natural resources such as plants and whereas polyester is made in a laboratory from coal. The ratio varies, with cotton and polyester being the most common. blends are also easily found. The blend is designed to afford the advantages of both the cotton and polyester fibres into one fabric.

QUESTION: 4

Which of the following substances is bio-degradable?

Solution: Biodegradable wastes are such waste materials that are and can be degraded by natural factors like microbes (e.g. bacteria, fungi, and a few more), abiotic elements like temperature, UV, oxygen, etc. Example: kitchen wastes and other natural wastes.

The cloth is a natural polymer made from cellulose. Cotton, silk, wool is biodegradable while plastics (thermoplastic, thermosetting plastics, PVC) are synthetic polymers and are non-biodegradable.

QUESTION: 5

A yarn can be split into fine strands of a thread. StateTrue or False.

Solution: Yarn itself is a loose thread and they can be split into thin strands.

QUESTION: 6

Ropes made of_______are used in cranes and lifts.

Solution: Ropes made of nylon are used in elevators and cranes because of its high tensile strength. Nylon is light and elastic and does not lose its strength with time thus it is used in elevators and cranes.

QUESTION: 7

__________is not a natural fibre.

Solution: Rayon is a manufactured regenerated cellulose fibre. It is made from purified cellulose, primarily from wood pulp, which is chemically converted into a soluble compound.

QUESTION: 8

Which resembles in properties with wool?

Solution: Acrylic, Orlon, and Acrilan are artificial and man-made fibres that resemble in properties with wool and is cheaper than actual wool and is colored with many dyes and sold in the market, They are made up of polyacrylonitrile and are used in making clothes, sweaters, carpets, and blankets. After discussing we can conclude that Acrylic, Orlon, and Acrilan have properties that resemble wool.

QUESTION: 9

The plastics which soften upon being heated but regain all their original properties on cooling are known as?

Solution: The plastics which soften upon being heated but remain an original property on cooking are known thermoplastics. Example: Polyethylene, PVC, Acrylic, Nylon, and Teflon

QUESTION: 10

The plastic that is used in making uniforms of firemen is

Solution: Melamine is a poor conductor of heat and resists fire. Most of the synthetic fibres are poor conductors of heat and electricity. However, melamine is used as a coating on the uniforms of firemen as they are flame resistant.

QUESTION: 11

Which plastic is called fireproof plastic?

Solution: Melamine is a poor conductor of heat and resists fire. Most of the synthetic fibres are poor conductors of heat and electricity. However, melamine is used as a coating on the uniforms of firemen as they are flame resistant.

QUESTION: 12

Shellac secreted by lac insects is:

Solution: Shellac is a resin secreted by the female lac bug on trees in the forests of India and Thailand. So a natural resin. Shellac is a natural bioadhesive polymer and is chemically similar to synthetic polymers, and thus can be considered a natural form of plastic. It can be turned into a molding compound when mixed with wood flour and molded under heat and pressure methods, so it can also be classified as thermoplastic. So a natural elastic.

QUESTION: 13

Which of the following is known as regenerated fibre?

Solution: Rayon is known as a regenerated fiber because it is manufactured from natural resources like cellulose present in wood pulp and short fibres.

QUESTION: 14

Which of these fibres is non-biodegradable?

Solution: Nylon fiber is non - biodegradable as it is synthetic fibre.

QUESTION: 15

Incineration of plastics causes:

Solution: Burning plastic creates harmful dioxins and if incinerators are inefficient, these leak into the environment. Modern incinerators are said to have largely solved this problem. But climate change is another consideration.