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
Oils and lubricants help in reducing friction because they
  • A
    Fill the irregularities in surface
    Correct
  • B
    Increase the rolling friction
  • C
    Make the surface coarse
  • D
    Decrease the rolling friction
2
Striker moves longer distance on carom when
  • A
    Striker is new
  • B
    Carom board is neat and clean
  • C
    Striker is old
  • D
    Powder is sprinkled
    Correct
3
Which of the following method is not used to reduce friction?
  • A
    Greasing
  • B
    Treading the tyres of vehicles
    Correct
  • C
    Using ball bearing
  • D
    Lubricating
4
The force of friction which comes into play when one body moves over the surface of other body is called
  • A
    Static friction
  • B
    Kinetic friction
    Correct
  • C
    Sliding friction
  • D
    Rolling friction
5
Rolling friction and sliding friction are two types of
  • A
    Static friction
  • B
    Fluid friction
  • C
    Dynamic or kinetic friction
    Correct
  • D
    Directional friction
6
When the friction is more
  • A
    Both bodies are in liquid state
  • B
    Two bodies in contact are rough
    Correct
  • C
    Two bodies in contact are smooth
  • D
    One body is rough and other is smooth
7
The frictional force that counterbalance the applied force during stationary state is called
  • A
    Static friction
    Correct
  • B
    Rolling friction
  • C
    Kinetic friction
  • D
    Momentary friction
8
In which of the substance friction is less
  • A
    Water
  • B
    Kerosene
  • C
    Ice
  • D
    Air
    Correct
9
Friction offered by water is good for the
  • A
    All of the above
  • B
    Breathing of aquatic plants
  • C
    Movement of ships or boat
    Correct
  • D
    Respiration of aquatic organisms
10
It is difficult to apply brakes to stop the moving ship because
  • A
    Friction exerted by water is absent
  • B
    There is no friction between solid and liquid
  • C
    Friction exerted by water is very high
  • D
    Friction exerted by water is very small
    Correct
11
Friction of air can be observed if a falling object is
  • A
    Light
    Correct
  • B
    Small
  • C
    Heavy
  • D
    Large
12
A coin and a feather are dropped from same height, which one will reach first on the ground?
  • A
    Both together
  • B
    Feather
  • C
    Coin
    Correct
  • D
    Depends upon size of coin
13
Which of the following living organisms have streamlined body?
  • A
    Elephant and human
  • B
    Dog and horse
  • C
    All of the above
  • D
    Fish and birds
    Correct
14
Which of the following method is applied in moving parts of machine to reduce friction?
  • A
    Converting rolling friction into sliding friction
  • B
    Using oils and lubricants
  • C
    Polishing the area of contact
  • D
    Converting sliding friction into rolling friction
    Correct
15
To walk on slippery ground is difficult because the
  • A
    Frictional force is not enough to prevent slip
    Correct
  • B
    Habit of walking on slippery ground is not enough to us
  • C
    Frictional force is very high to walk
  • D
    Ground offer very high resistance to walk