MCQExams
0:0:1
CBSE
JEE
NTSE
NEET
Practice
Homework
×
CBSE Questions for Class 8 Chemistry Synthetic Fibres And Plastics Quiz 6 - MCQExams.com
CBSE
Class 8 Chemistry
Synthetic Fibres And Plastics
Quiz 6
Why is plastic used in covering of electrical appliances?
Report Question
0%
It is a good conductors of heat
0%
It is a good conductor of electricity
0%
It is a poor conductor of electricity
0%
None of above
Explanation
Plastic is a poor conductor of electricity.
This makes it suitable to use as a coating for electric wires and in many other electrical appliances.
Hence, the correct option is $$C$$.
Which plastic is called a fire proof plastic?
Report Question
0%
Melamine
0%
Bakelite
0%
Teflon
0%
Acrylic
Explanation
Melamine is a poor conductor of heat and resists fire. Most of the synthetic fibers are poor conductors of heat and electricity. However, melamine can resist fire and can tolerate heat better than any other plastic material. Melamine is used for making floor tiles, kitchenware, and fabrics that resist fires.
Option $$A$$ is correct.
Which of the following statement is true about thermosetting plastic?
Report Question
0%
It undergoes irreversible change during curing
0%
It can melt and take shape only once
0%
It cannot be recycled
0%
All of above
Explanation
Thermosetting plastics contain polymers that cross-link together during the curing process to form an irreversible chemical bond. It can't be recycled. The cross-linking process eliminates the risk of the product remelting when heat is applied, making thermosetting ideal for high-heat applications such as electronic appliances.
Which of the following statement is false about plastic?
Report Question
0%
Low thermal conductivity
0%
They are highly reactive
0%
Low ductility
0%
Combustible
Explanation
Plastic is non-reactive material. Hence, plastics are used in many packaging materials. Except for the property given in option B, all others are properties of plastic.
So, option B is the correct answer.
Which of the following is considered as the first thermoplastic?
Report Question
0%
PVC
0%
Polystyrene
0%
Melamine
0%
Celluloid
Explanation
Celluloid, which is considered the first thermoplastic, made its appearance in the mid- $$1800s$$ and reigned in the industry for approximately $$100$$ years. During its peak production, it was used as a substitute for ivory. Today, it is used to make guitar picks.
Plastic is a polymer consisting of:
Report Question
0%
synthetic monomers
0%
semi-synthetic monomers
0%
natural monomers
0%
Both A and B
Explanation
Plastic is a material consisting of synthetic or semi-synthetic organics that can be moulded into solid objects of diverse shapes. Plastics are typically organic polymers of high molecular mass, but they often contain other substances. They are usually synthetic, most commonly derived from petrochemicals.
Which plastic is commonly used to make carry bags?
Report Question
0%
Polythene
0%
Polyester
0%
PET
0%
Acrylic
Explanation
Polyethene is a thermoplastic polymer consisting of long hydrocarbon chains. Polyethene or polythene is the most common plastic. Its primary use is in the packaging, making carry bags, plastic films, containers including bottles, etc.
Which of the following statement is true about non-biodegradable materials?
Report Question
0%
They are safe for environment
0%
The wastes are made up of synthetic material
0%
They can be constantly reused
0%
The wastes are made up of natural ingredients
Explanation
Non-biodegradable materials are those which do not decompose by natural processes. Non-biodegradable materials are generally synthetic polymers. They are not safe for the environment. Natural fibres degrade very easily in nature. However, non-biodegradable materials are made up of synthetic materials which are not broken down by micro-organisms.
Why are plastics difficult to biodegrade?
Report Question
0%
They are not environment friendly
0%
Burning process is slow
0%
They release lot of poisonous fumes
0%
All of above
Explanation
Plastic takes several years to decompose. It burns very slowly and also releases poisonous fumes which cause air pollution. The crucial manufacturing step turns petroleum into a material unrecognized by the organisms that normally break organic matter down.
Plastics are mainly used by everyone because :
Report Question
0%
They are cheap
0%
Easy to handle
0%
Do not break
0%
Light weight
Explanation
Plastics are mainly used by everyone because it is light weight, cheap, easy to handle and does not break easily.
_____ waste products can also be called green waste, or organic waste.
Report Question
0%
Biodegradable
0%
Non-Biodegradable
0%
synthetic
0%
None of these
Explanation
Biodegradable wastes are those that can be broken down by the action of micro-organisms and other environmental factors into carbon dioxide or other simple organic molecules. Biodegradable waste products can also be called green waste or organic waste because most of these are plant or animals based.
What are biodegradable compounds?
Report Question
0%
Compounds which can not be decomposed
0%
Compounds which can be decomposed by man-made processes
0%
Compounds which can be decomposed by natural processes
0%
All of the above
Explanation
Biodegradable compounds are compounds that get decomposed through natural processes such as the action of bacteria. Examples of biodegradable substances are peels of fruits, vegetables, paper.
Handles of most pans are made up of ____.
Report Question
0%
metals
0%
plastic
0%
Both A and B
0%
None of the above
Explanation
Metals are good conductors of heat as well as heavy. So, a pan with a metal handle would be hot while cooking. Also, it would mean that the pan would become very heavy.
Plastic on the other hand, is light and a bad conductor of heat. So, a plastic handle would not become as hot.
Hence, option B is correct.
Which of the following item cannot be recycled?
Report Question
0%
Plastic milk bottles
0%
Plastic food trays
0%
CD/DVD cases
0%
Plastic cups
Explanation
Plastic containers are relatively dense and compact which enables them to be easily sorted mechanically into the different types of plastics. Plastic film and bags are not easily mechanically sorted making them very costly to sort. Also, recycling such plastic is an expensive process.
CVD/DVD cases are made up of thermosetting polymers which cannot be recycled.
Option C is correct.
Plastic can be used as :
Report Question
0%
insulator
0%
conductor
0%
Both A and B
0%
None of above
Explanation
Most plastics are both thermal and electrical insulators, meaning they show high resistance to electrical current and are poor conductors of heat.
Thermosetting polymer such as bakelite are used as electrical insulators.
Cotton cloth requires _______ to decompose.
Report Question
0%
more than 15 years
0%
10-15 years
0%
100 years
0%
2-5 months
Explanation
Cotton is a natural fibre. It consists of natural components. Cotton takes 2 to 5 months to decompose.
______ is an example of biodegradable material.
Report Question
0%
Aluminium
0%
Plastic
0%
Cotton
0%
None of these
Explanation
Cotton is a biodegradable material. Other biodegradable materials are paper, wood, peels of vegetable and fruits, leftover foodstuff, etc. Non-biodegradable materials are plastics, aluminium and other metals.
Which type of fiber is flax?
Report Question
0%
Leaf fiber
0%
Bast fiber
0%
Animal fiber
0%
Fruit fiber
Explanation
Flax is a bast fiber also known as skin fiber. These fibers are collected from skin or bast surrounding the stem of the plant source. They have higher tensile strength than other fibers. These are used for durable yarns, fabric, packaging etc.
Examples of non-biodegradable is/are :
Report Question
0%
Tires
0%
Plastic
0%
Electronic components
0%
All of these
Explanation
Non-biodegradable
waste is a waste that does not break down into natural components and exists in the environment for a long time. Examples would be
tires
, plastics,
electronic
components, metals, etc
Option $$D$$ is correct.
Plastic can be used for:
Report Question
0%
polythene bags
0%
food packaging
0%
electrical appliances
0%
All of the above
Explanation
Plastic in today's world plays a very important role in day to day life. They are most commonly used as polythene bags (carry bags). Also, they are used in food industry for packaging as wrappers, packs for milk etc. Plastics can be good thermal insulator. Hence, covering electrical wires/appliances with plastic helps in avoiding electrical shocks.
Which of the following is an animal fiber?
Report Question
0%
Silk
0%
Wool
0%
Alpaca
0%
All of the above
Explanation
Animal fibers are generally made up of proteins.
Examples include silk, wool, angora, mohair, and alpaca. Silk fiber collected from dried saliva of bugs or insects during the preparation of cocoons.
Avian fibers from birds, for example, feathers and feather fiber.
_______ provides good heat and sound insulation.
Report Question
0%
Propylene
0%
Styrofoam
0%
Polythene
0%
Acrylic
Explanation
Polystyrene foam is also known as Styrofoam is brittle in tension, lightweight, with good heat and sound insulation. It is available in blocks and used for product modeling.
Define plasticity.
Report Question
0%
Ability to regain its original shape.
0%
Ability to flow when subjected to stress.
0%
Ability to change shape permanently.
0%
Both B and C.
Explanation
Plasticity is the ability of certain solids to flow or to change shape permanently when subjected to stresses of intermediate magnitude between those producing temporary deformation, or elastic behavior, and those causing failure of the material, or rupture.
Plasticity enables a solid under the action of external forces to undergo permanent deformation without rupture.
Rayon is a/an:
Report Question
0%
natural silk
0%
artificial silk
0%
regenerated fibre
0%
none of these
Explanation
Rayon is not a naturally occurring silk but manufactured by chemical treatment of a natural material, wood pulp. Rayon is obtained from natural sources yet it is man-made and so, it is called a semi-synthetic (or regenerated) fiber.
Hence, C is the correct option.
Which of the following can absorb over 90% of its own mass of water and also does not stick to wounds?
Report Question
0%
Saran
0%
Thiokol
0%
Rayon
0%
Gun cotton
Explanation
Rayon can absorb over 90% of its own mass of water and also does not stick to wounds. Rayon is a manufactured regenerated cellulose fiber. It is made from purified cellulose, primarily from wood pulp, which is chemically converted into a soluble compound.
When plastics are burnt, toxic substances are released into air causing ___________ pollution.
Report Question
0%
water
0%
air
0%
soil
0%
None of these
Explanation
When plastics are burnt toxic substances are released into air causing air pollution.
Fibres that are obtained from plants and animals are called
Report Question
0%
natural fibres
0%
synthetic fibres
0%
plastics
0%
none of these
Explanation
Fibres obtained from natural sources like plants and animals are known as natural fibres.
Examples of natural fibres are wool, silk, etc.
Synthetic fibres and plastics are made by human beings using chemical methods.
___________________ are obtained from cotton plant and sheep respectively.
Report Question
0%
Wool and cotton
0%
Cotton and wool
0%
Silk and wool
0%
Wool and silk
Explanation
Cotton is obtained from the fruit of the cotton plants and wool is
obtained from
sheep.
Hence, option B is correct.
Plastics are ____________ in water.
Report Question
0%
highly soluble
0%
slightly soluble
0%
insoluble
0%
sparingly soluble
Explanation
Plastics are insoluble in water and it cannot be dissolved in water.
This is because of the non-polar nature of the plastic.
Bed sheets, curtains, tents, parachutes etc are made from :
Report Question
0%
Natural fibres
0%
Synthetic fibres
0%
Rayon
0%
None of these
Explanation
Fibres
which are man-
made
are called synthetic fibres and which occurs naturally are called natural fibres. Rayon (synthetic fibre), when mixed with cotton (natural fibre), is used to making
curtains
,
bedsheets
etc
. of clothes, ropes, seat-belts,
curtains
, sleeping bags,
parachutes
,
tents etc
.
0:0:1
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
0
Answered
0
Not Answered
0
Not Visited
Correct : 0
Incorrect : 0
Report Question
×
What's an issue?
Question is wrong
Answer is wrong
Other Reason
Want to elaborate a bit more? (optional)
Practice Class 8 Chemistry Quiz Questions and Answers
<
>
Support mcqexams.com by disabling your adblocker.
×
Please disable the adBlock and continue.
Thank you.
Reload page
