Class 8 Synthetic Fibres And Plastics CBSE Questions & Answers

Class 8 · Synthetic Fibres And Plastics

This is Science Class 8 Synthetic Fibres and Plastics CBSE Questions & Answers. There are 15 questions in this test with each question having around four answer choices.

Questions & Answers

1
Plastic means :
  • A
    incapable of conducting heat and electricity
  • B
    capable of conducting heat and electricity
  • C
    capable of being moulded
    Correct
  • D
    incapable of being moulded
2
Read the following statements :i) Synthetic fibres are chemically inert.ii) Synthetic fibres are attacked by acids and alkalies.
  • A
    Statement i) is wrong and ii) is correct
  • B
    Statement ii) is wrong and i) is correct
    Correct
  • C
    both are wrong
  • D
    both are correct
3
All electrical wires used in household fittings contain a plastic covering because plastics are :
  • A
    semi conductors of electricity
  • B
    bad conductors of electricity
    Correct
  • C
    good conductors of electricity
  • D
    non durable
4
Thermosetting plastics contain cross-linked polymeric chains so they can be used :
  • A
    only twice
  • B
    only once
    Correct
  • C
    many times
  • D
    only thrice
5
Fine hair like structures are twisted together to make :
  • A
    fibre
  • B
    cloth
  • C
    fabric
  • D
    thread
    Correct
6
Plastics that can be reclaimed from wastes are :
  • A
    thermoplastics
    Correct
  • B
    both thermoplastics & thermosetting plastics
  • C
    none of them
  • D
    thermosetting plastics
7
It was called miracle fibre and replaced silk, this fibre is :
  • A
    nylon
    Correct
  • B
    wool
  • C
    rayon
  • D
    acrylic
8
This fibre is crease resistant and marketed under different names as terylene and terene. This fibre is :
  • A
    acrylic
  • B
    polyester
    Correct
  • C
    nylon
  • D
    rayon
9
PTFE is better known as:
  • A
    Rayon
  • B
    Nylon
  • C
    Teflon
    Correct
  • D
    Dacron
10
Terylene, Terene & Dacron are made by repeating units of :
  • A
    a phenol
  • B
    an ester
    Correct
  • C
    a aldehyde
  • D
    cellulose
11
In a hot and humid weather, synthetic fibres :
  • A
    very easy to handle because dry very quickly
  • B
    are very comfortable because absorb little water
  • C
    stick to the body and feel uncomfortable
    Correct
  • D
    absorb sweat of the body makes feel comfortable
12
Synthetic clothes shouldn’t be worn while burning crackers because:
  • A
    they may cause lung cancer at that time
  • B
    they may cause irritation in the presence of cracker fumes & smoke
  • C
    they may decrease the enjoyment due to their sticky nature
  • D
    they may cause severe burn injuries if catch fire
    Correct
13
Main source of raw material for producing plastics is :
  • A
    refined oil
  • B
    LPG
  • C
    crude oil
    Correct
  • D
    CNG
14
Plastic buckets are used to store water because :
  • A
    plastics are insoluble in water
    Correct
  • B
    plastics are poor conductor of heat
  • C
    plastics are soluble in water
  • D
    plastics are bad conductor of electricity
15
Read the following statements :i) Plastics are environment friendly.ii) Plastics are good conductors of heat and electricity.
  • A
    Statement ii) is correct but i) is wrong.
  • B
    both are wrong.
    Correct
  • C
    both are correct
  • D
    Statement i) is correct but ii) is wrong.