🧵 Synthetic Fibres and Plastics – MCQs for Class 8 Science

Part 2: Q26 – Q50

Q26. Which of the following is a natural polymer?

A) Nylon
B) Silk
C) Polyester
D) Acrylic

✅ Correct Answer: B) Silk

Explanation:

• A) Nylon – Synthetic polymer.
• B) Silk – ✔ Natural fibre, protein polymer.
• C) Polyester – Synthetic polymer.
• D) Acrylic – Synthetic wool fibre.

Q27. Which plastic is commonly used in making carry bags?

A) Bakelite
B) Polythene
C) Melamine
D) Teflon

✅ Correct Answer: B) Polythene

Explanation:

• A) Bakelite – Switches, handles.
• B) Polythene – ✔ Used in bags, packaging.
• C) Melamine – Crockery.
• D) Teflon – Non-stick cookware.

Q28. Which of these fibres absorbs very little water and dries quickly?

A) Cotton
B) Polyester
C) Wool
D) Silk

✅ Correct Answer: B) Polyester

Explanation:

• A) Cotton – Absorbs water, dries slowly.
• B) Polyester – ✔ Does not absorb much water, quick-drying.
• C) Wool – Absorbs moisture.
• D) Silk – Absorbs moisture.

Q29. The full form of PET is:

A) Polyethylene Tetraoxide
B) Polyethylene Terephthalate
C) Polyethylene Tetrahydride
D) Polyethylene Tetrachloride

✅ Correct Answer: B) Polyethylene Terephthalate

Explanation:

• A) Polyethylene Tetraoxide – Wrong.
• B) Polyethylene Terephthalate – ✔ Correct expansion of PET.
• C) Polyethylene Tetrahydride – Incorrect.
• D) Polyethylene Tetrachloride – Incorrect.

Q30. Which plastic is used in making non-breakable bottles?

A) PET
B) PVC
C) Teflon
D) Bakelite

✅ Correct Answer: A) PET

Explanation:

• A) PET – ✔ Used for bottles, jars.
• B) PVC – Used for pipes.
• C) Teflon – Non-stick pans.
• D) Bakelite – Switches, handles.

Q31. Which of the following fibres is prepared from coal, air, and water?

A) Rayon
B) Nylon
C) Acrylic
D) Polyester

✅ Correct Answer: B) Nylon

Explanation:

• A) Rayon – From wood pulp.
• B) Nylon – ✔ Made from coal, air, water.
• C) Acrylic – Synthetic wool.
• D) Polyester – Synthetic fibre, not from coal, air, water.

Q32. Which of these plastics is a poor conductor of electricity?

A) Polythene
B) PVC
C) Bakelite
D) All of these

✅ Correct Answer: D) All of these

Explanation:

• A) Polythene – Insulator.
• B) PVC – Insulator.
• C) Bakelite – Insulator, used in switches.
• D) All of these – ✔ All plastics are poor conductors.

Q33. Which property of plastics makes them harmful to the environment?

A) Strong
B) Non-biodegradable
C) Light weight
D) Transparent

✅ Correct Answer: B) Non-biodegradable

Explanation:

• A) Strong – Advantage.
• B) Non-biodegradable – ✔ Main environmental issue.
• C) Light weight – Advantage.
• D) Transparent – Not harmful.

Q34. Which of the following is a thermosetting plastic?

A) Bakelite
B) Melamine
C) Both A and B
D) PVC

✅ Correct Answer: C) Both A and B

Explanation:

• A) Bakelite – ✔ Thermosetting.
• B) Melamine – ✔ Thermosetting.
• C) Both A and B – ✔ Correct.
• D) PVC – Thermoplastic.

Q35. The advantage of synthetic fibres over natural fibres is:

A) Wrinkle resistance
B) Durability
C) Cheaper cost
D) All of these

✅ Correct Answer: D) All of these

Explanation:

• A) Wrinkle resistance – True for synthetics.
• B) Durability – Strong and long-lasting.
• C) Cheaper cost – Lower than silk, wool.
• D) All of these – ✔ Correct.

Q36. Which is a fully synthetic fibre?

A) Nylon
B) Rayon
C) Wool
D) Silk

✅ Correct Answer: A) Nylon

Explanation:

• A) Nylon – ✔ First fully synthetic fibre.
• B) Rayon – Semi-synthetic.
• C) Wool – Natural.
• D) Silk – Natural.

Q37. Which plastic is used in making firemen’s uniforms?

A) Polyester
B) Melamine
C) Nylon
D) Bakelite

✅ Correct Answer: B) Melamine

Explanation:

• A) Polyester – Clothes, PET bottles.
• B) Melamine – ✔ Fire-resistant, used in uniforms.
• C) Nylon – Strong, but burns.
• D) Bakelite – Switches, not uniforms.

Q38. Which of the following is a disadvantage of plastics?

A) Strong and light
B) Non-reactive
C) Non-biodegradable
D) Insulating property

✅ Correct Answer: C) Non-biodegradable

Explanation:

• A) Strong and light – Advantage.
• B) Non-reactive – Advantage.
• C) Non-biodegradable – ✔ Major drawback.
• D) Insulating property – Advantage.

Q39. Which is called artificial wool?

A) Polyester
B) Rayon
C) Acrylic
D) Nylon

✅ Correct Answer: C) Acrylic

Explanation:

• A) Polyester – Synthetic fibre, not wool-like.
• B) Rayon – Artificial silk.
• C) Acrylic – ✔ Artificial wool.
• D) Nylon – Used in ropes.

Q40. Which of these plastics is used for insulation of wires?

A) Bakelite
B) PVC
C) Melamine
D) Teflon

✅ Correct Answer: B) PVC

Explanation:

• A) Bakelite – Switches, handles.
• B) PVC – ✔ Good insulator, used in wire covering.
• C) Melamine – Crockery.
• D) Teflon – Non-stick coating.

Q41. Which fibre is also called polyamide?

A) Polyester
B) Nylon
C) Rayon
D) Acrylic

✅ Correct Answer: B) Nylon

Explanation:

• A) Polyester – PET/Terylene.
• B) Nylon – ✔ Belongs to polyamide group.
• C) Rayon – Semi-synthetic.
• D) Acrylic – Synthetic wool.

Q42. Which property of plastics makes them useful in making utensils?

A) Conductivity
B) Light weight and non-reactive
C) Non-biodegradable
D) Transparency

✅ Correct Answer: B) Light weight and non-reactive

Explanation:

• A) Conductivity – Plastics are insulators.
• B) Light weight & non-reactive – ✔ Don’t react with food.
• C) Non-biodegradable – Disadvantage.
• D) Transparency – Not the main reason.

Q43. Which fibre melts on heating and sticks to the body?

A) Nylon
B) Wool
C) Cotton
D) Silk

✅ Correct Answer: A) Nylon

Explanation:

• A) Nylon – ✔ Melts and sticks when heated.
• B) Wool – Burns with smell of hair.
• C) Cotton – Burns to ash.
• D) Silk – Burns but doesn’t melt like nylon.

Q44. Which of these is used in bulletproof vests?

A) Acrylic
B) Polyester
C) Kevlar
D) Nylon

✅ Correct Answer: C) Kevlar

Explanation:

• A) Acrylic – Artificial wool.
• B) Polyester – Clothes, bottles.
• C) Kevlar – ✔ Special polymer for bulletproof material.
• D) Nylon – Ropes, parachutes.

Q45. Which of the following is a biodegradable fibre?

A) Nylon
B) Polyester
C) Cotton
D) Acrylic

✅ Correct Answer: C) Cotton

Explanation:

• A) Nylon – Non-biodegradable.
• B) Polyester – Non-biodegradable.
• C) Cotton – ✔ Natural fibre, biodegradable.
• D) Acrylic – Non-biodegradable.

Q46. Which is the most common synthetic fibre used in making clothes?

A) Polyester
B) Nylon
C) Acrylic
D) Rayon

✅ Correct Answer: A) Polyester

Explanation:

• A) Polyester – ✔ Commonly used in fabrics.
• B) Nylon – Used in ropes.
• C) Acrylic – Used as wool substitute.
• D) Rayon – Artificial silk.

Q47. Which plastic is used for making kitchenware that resists heat?

A) Melamine
B) Bakelite
C) PVC
D) Polyester

✅ Correct Answer: A) Melamine

Explanation:

• A) Melamine – ✔ Heat resistant, used in plates/cups.
• B) Bakelite – Switches.
• C) PVC – Pipes.
• D) Polyester – Clothes.

Q48. Which is the first fully synthetic fibre?

A) Nylon
B) Rayon
C) Polyester
D) Acrylic

✅ Correct Answer: A) Nylon

Explanation:

• A) Nylon – ✔ First fully synthetic fibre (1931).
• B) Rayon – Semi-synthetic.
• C) Polyester – Later development.
• D) Acrylic – Later development.

Q49. Which of these fibres is wrinkle-free?

A) Cotton
B) Polyester
C) Silk
D) Wool

✅ Correct Answer: B) Polyester

Explanation:

• A) Cotton – Wrinkles easily.
• B) Polyester – ✔ Wrinkle-free.
• C) Silk – Wrinkles easily.
• D) Wool – Can wrinkle.

Q50. Which plastic is used in making electrical insulation tape?

A) PVC
B) Teflon
C) Bakelite
D) Polyester

✅ Correct Answer: A) PVC

Explanation:

• A) PVC – ✔ Flexible, insulator, used in insulation tapes.
• B) Teflon – Non-stick cookware.
• C) Bakelite – Switches.
• D) Polyester – Clothes, bottles.

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