MCQ Questions for Class 8 Science: Ch 12 Friction
1. Which of the following produces least friction?
(a) Sliding friction
(b) Rolling friction
(c) Composite friction
(d) Static friction
► (b) Rolling friction
2. In machine, friction between moving parts is reduced by
(a) Heating machine
(b) Using powder
(c) Using lubricants
(d) Using paints
► (c) Using lubricants
3. Why is a carrom board usually powdered before playing?
(a) For increasing friction
(b) For decreasing friction
(c) For decoration
(d) For fragrance
► (b) For decreasing friction
4. Thermos flask keeps hot liquid hot and cold liquid cold by
(a) Heating
(b) Friction
(c) Preventing heat loss
(d) Cooling
► (c) Preventing heat loss
5. Substances are called lubricants which are used to
(a) increase friction
(b) decrease friction
(c) increase or decrease friction
(d) none of these
► (b) decrease friction
6. Which force prevents us from slipping while walking on the road?
(a) Muscular force of our body
(b) Gravitational pull by the earth
(c) Frictional force
(d) Balanced forces of nature
► (c) Frictional force
7. Which of the following activities is easier to perform on a drum of 10 kg?
(a) Dragging the drum
(b) Lifting the drum
(c) Rolling the drum
(d) All of the above need the same effort
► (c) Rolling the drum
8. The substance which reduce friction are called
(a) Lubricants
(b) Wheels
(c) Powder
(d) Graphite
► (a) Lubricants
9. A toy car released with the same initial speed will travel farthest on
(a) Muddy surface
(b) Cemented surface
(c) Brick surface
(d) Polished marble surface
► (d) Polished marble surface
10. Which of the following materials is likely to have the least friction?
(a) Wood
(b) Cardboard
(c) Glass
(d) Paper
► (c) Glass
11. Friction is a __________
(a) Contact force
(b) Non-contact force
(c) Magnetic force
(d) None of these
► (a) Contact force
12. Fluids are
(a) gases
(b) liquids
(c) gases and liquids both
(d) none of these
► (c) gases and liquids both
13. In the decreasing order of magnitude, which of the following is correct?
(a) Rolling < static < sliding friction
(b) Static > sliding > rolling friction
(c) Static > rolling > sliding friction
(d) Sliding < static < rolling friction
► (b) Static > sliding > rolling friction
14. Which of the following statements is NOT true?
(a) Friction can be reduced by converting sliding friction into rolling friction.
(b) Friction in air and water can be reduced by streamlining the shape of the objects.
(c) A polished surface will have less friction.
(d) Friction can be reduced to zero.
► (d) Friction can be reduced to zero.
15. Striking a matchstick produces fire by
(a) Contact force
(b) Friction
(c) Chemical reaction
(d) Physical reaction
► (b) Friction
16. The shape of fish is streamlined to
(a) Change the direction
(b) Increase fluid friction
(c) Facilitate breathing
(d) Decrease fluid friction
► (d) Decrease fluid friction
17. Friction produces
(a) Motion
(b) Force
(c) Heat
(d) Light
► (c) Heat
18. Why are certain bodies streamlined?
(a) To increase friction
(b) To decrease weight
(c) To reduce friction
(d) To increase weight
► (c) To reduce friction
19. Carpenters often grease screws before fixing them to
(a) Decrease friction
(b) Increase friction
(c) Make it light weight
(d) All of the above
► (a) Decrease friction
20. Soapy water on floor would make it
(a) More clean
(b) Difficult to walk
(c) More hygienic
(d) Easier to walk
► (b) Difficult to walk
21. Brakes of vehicle is stopped by using brake that works on property of
(a) Pressure
(b) Acceleration
(c) Retardation
(d) Friction
► (d) Friction
22. Friction always
(a) helps the motion
(b) opposes the motion
(c) both of these
(d) none of these
► (b) opposes the motion
23. If a body moves on the sandy surface, its motion will
(a) Increase
(b) Decrease
(c) Neither increase nor decrease
(d) None of these
► (b) Decrease
24. Why are spikes provided in the shoes of athletes?
(a) As a decoration
(b) To increase friction
(c) To decrease friction
(d) To give shape
► (b) To increase friction
25. Which of the following will offer least friction to run a toy car?
(a) Wet marble
(b) Towel
(c) Dry marble
(d) News paper
► (a) Wet marble