8th Grade > Chemistry
SYNTHETIC FIBRES AND PLASTICS MCQs
Total Questions : 35
| Page 1 of 4 pages
Answer: Option B. -> False
:
B
Based on the connections between their monomer units, plastics are classified as linear andcross-linked plastics.
∙ Linear plastics:the monomer units are connected in linear fashion.
∙ Cross-linked plastics:cross-links exists between two linear or branched chains,forming a three-dimensional network.
This arrangement of monomer units define the properties of polymers. Linear polymers can be bent easily, whereas bending cross-linked polymers is difficult.
:
B
Based on the connections between their monomer units, plastics are classified as linear andcross-linked plastics.
∙ Linear plastics:the monomer units are connected in linear fashion.
∙ Cross-linked plastics:cross-links exists between two linear or branched chains,forming a three-dimensional network.
This arrangement of monomer units define the properties of polymers. Linear polymers can be bent easily, whereas bending cross-linked polymers is difficult.
Answer: Option A. -> True
:
A
Silk is a natural fibre obtained from silkworm, which is an insect. The best-knownsilkis obtained from thecocoons of the mulberrysilkworm. A large quantity, around 10 kg of silkworm cocoons, is required to make just 1 kg of silk.
:
A
Silk is a natural fibre obtained from silkworm, which is an insect. The best-knownsilkis obtained from thecocoons of the mulberrysilkworm. A large quantity, around 10 kg of silkworm cocoons, is required to make just 1 kg of silk.
Answer: Option B. -> False
:
B
Thermosetting plastics are those plastics which oncemouldedcannot be remouldedby heating. They are strong, durable and resists heat to a large extent.The well known examples are bakelite and melamine.
On the other hand, thermoplastics can be repeatedly moulded if they are heated above a specific temperature. For example, PVC, nylon, etc.
:
B
Thermosetting plastics are those plastics which oncemouldedcannot be remouldedby heating. They are strong, durable and resists heat to a large extent.The well known examples are bakelite and melamine.
On the other hand, thermoplastics can be repeatedly moulded if they are heated above a specific temperature. For example, PVC, nylon, etc.
Answer: Option B. -> False
:
B
:
B
- Plastic is very light, strong and durable. In addition to these, it can also be moulded into different shapes and sizes.
- So, it is used for various purposesin industriesand for the manufacture of household products.
- Since plasticischeaper, lighter and chemically unreactive as compared to metals, it isusedin cars, aircrafts and spacecrafts.
Answer: Option A. -> True
:
A
A material which is not easily decomposed by natural processes is termed asnon-biodegradable. Plastic is generally considered non-biodegradable asit cannot bedegraded by bacteria.
Plastic bags and other plastic items, that we use in our daily lives, endup in landfills and are typically buried. Sincethey donot degrade, they pose a greater environmental threat than the biodegradable wastes do.
:
A
A material which is not easily decomposed by natural processes is termed asnon-biodegradable. Plastic is generally considered non-biodegradable asit cannot bedegraded by bacteria.
Plastic bags and other plastic items, that we use in our daily lives, endup in landfills and are typically buried. Sincethey donot degrade, they pose a greater environmental threat than the biodegradable wastes do.
Answer: Option B. -> Teflon
:
B
Anon-stick surface can reduce the ability of other materials to stick on it.These surfaces are coatedwith a synthetic polymer called teflon. Non-stick cookwareand the flat end of an electric iron are coated with teflon.
:
B
Anon-stick surface can reduce the ability of other materials to stick on it.These surfaces are coatedwith a synthetic polymer called teflon. Non-stick cookwareand the flat end of an electric iron are coated with teflon.
Answer: Option C. -> Polywool
:
C
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.
:
C
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.
Answer: Option B. -> sericulture.
:
B
Sericulture, orsilk farming, is the cultivation of silkwormsto produce silk.
:
B
Sericulture, orsilk farming, is the cultivation of silkwormsto produce silk.
Answer: Option C. -> Nylon
:
C
Nylon threads are strong, elastic and lightweight. A nylon wire is stronger than a steel wire having the same diameter. Hence, it is preferred for making parachutes.
Harness straps, tents, sleeping bags, sails, ropes, fishing poles, etc are also made from nylon fibers because of its strength.
:
C
Nylon threads are strong, elastic and lightweight. A nylon wire is stronger than a steel wire having the same diameter. Hence, it is preferred for making parachutes.
Harness straps, tents, sleeping bags, sails, ropes, fishing poles, etc are also made from nylon fibers because of its strength.
Answer: Option D. -> Bakelite
:
D
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,bakeliteis used for making electrical switches, handles of various utensils, etc.
:
D
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,bakeliteis used for making electrical switches, handles of various utensils, etc.
Latest Videos
Latest Test Papers
Login With Google
Old way of Login
Login With Email