Class 8 Friction CBSE Questions & Answers

Class 8 · Friction

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

Questions & Answers

1
The machine in which in which oil and lubricant cannot be used, friction is reduced by
  • A
    All of these
  • B
    Using dry powder
  • C
    Making spongy surface
  • D
    Creating air cushion
    Correct
2
A polished surface is
  • A
    Very slippery
  • B
    Entirely friction free
    Correct
  • C
    Very rough
  • D
    Very high friction
3
Sliding is replaced in most machines by
  • A
    Using powder
  • B
    Using graphite
  • C
    Using lubricants
  • D
    Use of ball bearings
    Correct
4
Metals are good conductor of heat because
  • A
    Particles are away from each other
  • B
    Particles are larger in size
  • C
    Particles are smaller in size
  • D
    Particles are very close to each other
    Correct
5
In which of the following articles bearing is not used?
  • A
    Fans
  • B
    Television
    Correct
  • C
    Bicycles
  • D
    Cars
6
Which of the following will exert less friction?
  • A
    Objects moving on rail
  • B
    Objects moving on road
  • C
    Objects moving in water
  • D
    Objects moving in air
    Correct
7
Liquids and gases together called
  • A
    Fluids
    Correct
  • B
    Liquidity
  • C
    Humidity
  • D
    Liquor
8
The frictional force on an object in a fluid depends on its
  • A
    Colour of the fluid
  • B
    Speed with respect to the fluid
    Correct
  • C
    Density of the fluid
  • D
    Mass of the object
9
All vehicles are designed to have shapes which
  • A
    Increase fluid friction
  • B
    Neglect fluid friction
  • C
    Make the fluid friction to zero
  • D
    Reduce fluid friction
    Correct
10
Tyres are treaded to
  • A
    Make more beautiful
  • B
    Increase friction
    Correct
  • C
    Increase the life
  • D
    Decrease friction
11
It is difficult to write on polished surface with pencil because
  • A
    Polished surface have less friction
    Correct
  • B
    Polished surface have high friction
  • C
    Polished surface have no friction
  • D
    Friction prevents the movement of pencil
12
Drag is the
  • A
    Frictional force exerted by liquid
    Correct
  • B
    Gravitational force exerted by liquid
  • C
    Frictional force exerted by solid
  • D
    Frictional force exerted by air
13
Boat and ship have pointed tips to
  • A
    Decrease friction due to liquid
    Correct
  • B
    Make them more attractive
  • C
    Increase friction due to liquid
  • D
    Increase the beauty
14
When we attempt to move any surface, we apply a force to overcome
  • A
    Vander wall force between surfaces
  • B
    Gravitational force of earth
  • C
    Interlocking between surfaces
    Correct
  • D
    Electrostatic force between particles
15
The sole of shoes becomes flat after using few months because of
  • A
    Wearing due to bad quality
  • B
    All of the above
  • C
    Wearing due to rough weather
  • D
    Wearing due to friction
    Correct