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Question 1
- ----------made from both synthetic and natural fibers.
- ---------- is the another name of lycra.
- ---------- fibre is also called artificial silk.
- Electrical switches are made of ----------.
- The process of combining monomers to form a polymer is called-------.
- Rayon is a fiber regenerated from---------.
- ------------ is often used are substitute for wool.
- ------------ is used as a coating on the surface of non- stick frying pans.
- -----------synthetic fiber is commonly used to make strong ropes.
- ---------- are long- chain polymers made by linking of several ester units.
- ----------plastics are set into a particular shape cannot be remolded.
- ---------- is the most common source for synthetic fibers.
- Plastic are an example of -----------.
- Themocol is made from--------- plastic material.
- Plastics are polymers that can be --------- and ---------- into any desired.
Answers
- Blended fibers
- Spandex
- Rayon
- Bakelite
- Polymerization
- Cellulose
- Acrylic
- Teflon
- Nylon
- Polyester
- Thermosetting
- Petroleum
- Non- biodegradable substance
- Polystyrene
- Melted and Molded
Question 2
i. ____is called a regenerated fibre.
ii. The full form of PVC is ___
iii. Synthetic fibres have ____. tensile strength.
iv. _____ is used to make bottles for packing mineral water.
v. Plastics do not react with water and ______
Answers
i. Rayon
ii. polyvinyl chloride
iii. high
iv. PET
v. air
Short Answer type
Question 1
Name any two blended fibres?
Answer
Terry cot (terrylene+ cotton)
Terry cot ( ferrylene+ wool)
Question 2
Why is rayon called a regenerated fibres?
Answer
Rayon is called regenerated fibers because the original raw material cellulose is broken down and then reformed.
Question 3
Why is nylon considered to be a good material for making fishing nets?
Answer
Being a strong and lightweight material, it is used for making fishing net.
Question 4
Why electric plugs and switches are made of plastic?
Answer
Plastics are poor conductor of heat and electricity so electric plug and switches are made of plastic
Question 5
Why are plastic bottles commonly used to store chemicals in a chemistry laboratory?
Answer
Plastics have no reaction with water and air. They are non- reactive and do not corrode easily so they are used to store chemicals in chemistry laboratory.
Question 6
What can be used as a substitute for wool? Why?
Answer
Acrylic can be used as a substitute for wool because it is a lightweight, soft and warm synthetic fiber which is wrinkle- resistant, cheaper than wool and resistant to moths and chemicals.
Question 7
Distinguish between natural and synthetic fibers?
Answer
Natural fibers come from plants and animals such as cotton, jute etc.
Synthetic fibers are made from chemicals which come from wood, coal and petroleum such as rayon, nylon etc.
Question 8
Why nylon is used for making socks?
Answer
Nylon fiber show good frictional resistance. It is elastic in nature and highly durable so it is used for making socks.
Question 9
Why people prefer wearing cotton clothes over synthetic during summer?
Answer
Synthetic fibers cannot absorb moisture. This makes them unsuitable to be worn during summer when our body sweats.
Question 10
Why Polyester clothes should be avoided in kitchen?
Answer
Polyester is highly flammable so they should be avoided in kitchen.
Question 11
State the following as True or False:
- Polyester is the strongest synthetic fibre.
- If plastics are burnt, they evolve oxygen gas.
- Bakelite is an example of thermoset.
- Terry wool is a blended fibre.
- Artificial silk is another name for silk.
Answer
i.False
ii.False
iii.True
iv.True
v.False
Question 12
Unscramble the following to form words.
- NOAYR
- FELTON
- LASPICT
- YESPOLTER
- YRCILCA
Answer
i. RAYON
ii. TEFLON
iii. PLASTIC
iv. POLYESTER
v. ACRYLIC
Question 13
Match the column
Answer
1-d
2- c
3-a
4-e
5-b
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