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
Nylon absorbs very little water hence it is most suitable for making :
  • A
    fishing net
  • B
    tyre cords
  • C
    all of these
    Correct
  • D
    parachute
2
We should never dispose off polythenes in the sewage system because:
  • A
    release toxic fumes and gases
  • B
    chokes drains and soil
    Correct
  • C
    all of them
  • D
    makes sewage non biodegradable
3
The $4^th$ R added to 3R concept is :
  • A
    recycle
  • B
    recover
    Correct
  • C
    reduce
  • D
    reuse
4
The scratch proof and corrosion resistant low friction protective coating on metal surface is :
  • A
    Teflon
    Correct
  • B
    Formica
  • C
    Nylon
  • D
    Dacron
5
All kinds of fibres are :
  • A
    monomers
  • B
    pentamers
  • C
    dimers
  • D
    polymers
    Correct
6
A regenerated synthetic fibre is one which is made up of :
  • A
    natural materials
    Correct
  • B
    recycled waste fibres
  • C
    dead and decaying organisms
  • D
    only chemicals
7
A nylon fibre is made entirely from chemicals hence it is :
  • A
    regenerated synthetic fibre
  • B
    pseudo synthetic fibre
  • C
    true synthetic fibre
    Correct
  • D
    natural fibre
8
We can control the physical properties of synthetic fibres by :
  • A
    rearranging the monomers
    Correct
  • B
    rearranging the dimers
  • C
    rearranging the polymer
  • D
    rearranging the tetramers
9
Bakelite do not melt on heating because such :
  • A
    polymers are attached by strong linear chains
  • B
    polymers are strong and inexpensive
  • C
    polymers are poor conductors of heat
  • D
    polymers are joined by strong cross links
    Correct
10
Which of the following will not be a polymer :
  • A
    natural rubber
  • B
    coir
  • C
    artificial silk
  • D
    none of them
    Correct
11
Nylon is a :
  • A
    natural fibre
  • B
    both true synthetic fibre & regenerated fibre
  • C
    regenerated fibre
  • D
    true synthetic fibre
    Correct
12
Nylon absorbs very little water hence it is most suitable for making:
  • A
    fishing net
  • B
    parachute
  • C
    all of these
    Correct
  • D
    tyre cords
13
Plastics are classified as thermoplastic and thermosetting plastic based on their behaviour :
  • A
    on ironing
  • B
    on cooling
  • C
    on heating
    Correct
  • D
    on passing electricity
14
Polythene is obtained by polymerization of :
  • A
    methylene monomers
  • B
    propylene monomers
  • C
    phenol & formaldehyde monomers
  • D
    ethylene monomers
    Correct
15
Thermoplastics can be :
  • A
    non melting
  • B
    never remoulded
  • C
    non recyclable
  • D
    destroyed by heating
    Correct