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
Which of the following method is applied to increase friction of vehicles?
  • A
    Less inflating the tyres
  • B
    Regular oiling of engine
  • C
    Cleaning of vehicles
  • D
    Treading of tyres
    Correct
2
The shoes of football player have spikes in their sole to
  • A
    Hard hitting the ball
  • B
    Decrease friction
  • C
    Make frictionless
  • D
    Increase friction
    Correct
3
Sand paper is used to clean the metal surface to remove rust as because
  • A
    Metal and sand paper reacts easily
  • B
    Sand paper has smooth surface to increase friction
  • C
    Sand paper has rough surface to decrease friction
  • D
    Sand paper has rough surface to increase friction
    Correct
4
In moving machine, friction
  • A
    Increase the efficiency of machine
  • B
    Decrease the energy loss
  • C
    Reduce the efficiency of machine
    Correct
  • D
    Increase the cost of machine
5
Friction involves
  • A
    Reduce the production
  • B
    Reduce the expenses of energy
  • C
    Unnecessary expenses of energy
    Correct
  • D
    Increase the life of machine
6
Sonic boom is due to
  • A
    Friction between air and gravitation
  • B
    Friction between air and supersonic object
    Correct
  • C
    Attraction between earth and atmosphere
  • D
    All of the above
7
Moving ball slowly decrease its speed in a grassy field due to
  • A
    Gravitational force of earth
  • B
    Static force of ball
  • C
    Rolling friction due to grass only
  • D
    Friction between ball and grass
    Correct
8
Friction is a
  • A
    Contact force acting in opposite direction
    Correct
  • B
    Non-contact force in same direction
  • C
    Contact force acting in same direction
  • D
    Non-contact force in opposite direction
9
The force responsible for changing the state of motion of an object is
  • A
    Gravitational force
  • B
    Friction
    Correct
  • C
    Muscular force
  • D
    Molecular force
10
Force of friction always acts on all
  • A
    Lighter object
  • B
    Heavy object
  • C
    Stationary object
  • D
    Moving object
    Correct
11
Which of the following is an example of contact force?
  • A
    Frictional force
    Correct
  • B
    Magnetic force
  • C
    Gravitational force
  • D
    Electrostatic force
12
Friction depends upon
  • A
    Nature of surface only
  • B
    Smoothness of surface and nature of surface
    Correct
  • C
    Smoothness of surface only
  • D
    Time of the activity
13
The force required to keep the object moving with same speed is a measure of
  • A
    Rolling friction
  • B
    Contact friction
  • C
    Static friction
  • D
    Sliding friction
    Correct
14
Which of the following is correct order in descending frictional force
  • A
    Rolling >static > sliding
  • B
    Rolling > sliding > static
  • C
    Static > sliding >rolling
    Correct
  • D
    Static > rolling > sliding
15
It is difficult to walk on an oily floor because
  • A
    Floor get spoiled
  • B
    Force of friction is absent
  • C
    Force of friction is very high
  • D
    Force of friction is very less
    Correct