Vidaara.orgClass 8 · Mathematics
CodeVID-M8-WS
Synthetic Fibres and Plastics — Practice Worksheet
Name: ____________________
Roll No.: __________
Date: ____________
General Instructions
- All questions are compulsory.
- Choose the correct option (A, B, C or D) for each question.
- The answer key is at the end — try the paper first!
Section A — Multiple Choice (1 mark each)
15 × 1 = 15 marks
1.
A thin, thread-like strand used to make fabrics is a:
- A.Fibre
- B.Metal
- C.Mineral
- D.Polymer unit
2.
Which of these is a natural fibre?
- A.Nylon
- B.Polyester
- C.Cotton
- D.Acrylic
3.
Synthetic fibres are mostly made from chemicals obtained from:
- A.Petroleum
- B.Cotton plants
- C.Sheep
- D.Silkworms
4.
The single small unit that joins to form a polymer is a:
- A.Monomer
- B.Polymer
- C.Fibre
- D.Atom only
5.
A polymer is a:
- A.Single small molecule
- B.Long chain of many monomers
- C.Type of metal
- D.Mixture of gases
6.
Rayon is made from:
- A.Wood pulp
- B.Petroleum only
- C.Wool
- D.Sand
7.
The first fully synthetic fibre, very strong and used in parachutes, is:
- A.Rayon
- B.Nylon
- C.Cotton
- D.Jute
8.
Which synthetic fibre does NOT crease easily and is good for dress material?
- A.Acrylic
- B.Rayon
- C.Polyester
- D.Wool
9.
The synthetic fibre that resembles wool is:
- A.Nylon
- B.Acrylic
- C.Rayon
- D.Polyester
10.
PET, used to make plastic bottles, is a type of:
- A.Nylon
- B.Polyester
- C.Rayon
- D.Acrylic
11.
Plastics that soften on heating and can be remoulded are called:
- A.Thermoplastics
- B.Thermosetting plastics
- C.Natural fibres
- D.Metals
12.
Bakelite and melamine are examples of:
- A.Thermoplastics
- B.Thermosetting plastics
- C.Natural fibres
- D.Metals
13.
Bakelite is used for electrical switches because it is a:
- A.Good conductor of electricity
- B.Poor conductor of heat and electricity
- C.Magnet
- D.Natural fibre
14.
A major environmental problem with plastic is that it is:
- A.Biodegradable
- B.Non-biodegradable
- C.Edible
- D.A good fuel only
15.
Which set of actions helps reduce plastic pollution?
- A.Reduce, Reuse, Recycle, Recover
- B.Burn all plastic openly
- C.Throw plastic in rivers
- D.Use more single-use plastic
Section B — Challenge / Olympiad (2 marks each)
6 × 2 = 12 marks
16.
A nylon thread can be stronger than a steel wire of the same thickness. This makes nylon especially suitable for:
- A.Climbing ropes and seat belts
- B.Window glass
- C.Cooking food
- D.Electric wires' metal core
17.
Terycot is made by mixing two fibres. They are:
- A.Terylene (polyester) and cotton
- B.Nylon and wool
- C.Rayon and silk
- D.Acrylic and jute
18.
Why are the handles of cooking utensils often made of thermosetting plastic rather than metal?
- A.The plastic is a poor conductor of heat, so the handle stays cool
- B.The plastic conducts heat better
- C.Metal is cheaper
- D.Plastic melts easily on heating
19.
Firefighters' suits are sometimes coated with melamine because melamine:
- A.Resists fire and heat
- B.Burns quickly
- C.Dissolves in water
- D.Conducts electricity
20.
Synthetic clothes can be dangerous near a flame because they:
- A.Melt and stick to the skin
- B.Turn to ash harmlessly
- C.Put out the fire
- D.Become stronger
21.
Why is it better to carry a cloth or jute bag instead of a plastic bag?
- A.Cloth and jute are biodegradable and reusable
- B.Plastic bags are biodegradable
- C.Cloth pollutes more
- D.Jute is non-renewable
Answer Key
Section A — Multiple Choice (1 mark each)
- (A) Fibre
- (C) Cotton
- (A) Petroleum
- (A) Monomer
- (B) Long chain of many monomers
- (A) Wood pulp
- (B) Nylon
- (C) Polyester
- (B) Acrylic
- (B) Polyester
- (A) Thermoplastics
- (B) Thermosetting plastics
- (B) Poor conductor of heat and electricity
- (B) Non-biodegradable
- (A) Reduce, Reuse, Recycle, Recover
Section B — Challenge / Olympiad (2 marks each)
- (A) Climbing ropes and seat belts
- (A) Terylene (polyester) and cotton
- (A) The plastic is a poor conductor of heat, so the handle stays cool
- (A) Resists fire and heat
- (A) Melt and stick to the skin
- (A) Cloth and jute are biodegradable and reusable
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