Vidaara.orgClass 8 · Mathematics
CodeVID-M8-WS
Friction — Practice Worksheet
Name: ____________________
Roll No.: __________
Date: ____________
General Instructions
- All questions are compulsory.
- Choose the correct option (A, B, C or D) for each question.
- The answer key is at the end — try the paper first!
Section A — Multiple Choice (1 mark each)
25 × 1 = 25 marks
1.
Friction is a force that:
- A.Helps motion
- B.Opposes relative motion
- C.Has no direction
- D.Increases speed
2.
Friction is mainly caused by the ______ of surfaces.
- A.Colour
- B.Roughness
- C.Temperature
- D.Weight
3.
The friction acting on an object that is sliding over a surface is:
- A.Static friction
- B.Sliding friction
- C.Rolling friction
- D.No friction
4.
Which type of friction is the smallest?
- A.Static
- B.Sliding
- C.Rolling
- D.All equal
5.
The correct order of friction from greatest to least is:
- A.Rolling > sliding > static
- B.Static > sliding > rolling
- C.Sliding > static > rolling
- D.Static > rolling > sliding
6.
Friction between two surfaces depends mainly on their nature and the force:
- A.Of gravity only
- B.Pressing them together
- C.Of the wind
- D.Of the sun
7.
Rougher surfaces generally produce ______ friction.
- A.Less
- B.More
- C.No
- D.Zero
8.
A heavier object on a surface experiences ______ friction than a lighter one.
- A.Less
- B.More
- C.The same
- D.No
9.
Polishing a surface usually ______ the friction.
- A.Increases
- B.Decreases
- C.Doubles
- D.Has no effect on
10.
For ordinary surfaces, the area of contact has ______ effect on friction.
- A.A very large
- B.Little
- C.The greatest
- D.An infinite
11.
Friction between our shoes and the ground allows us to:
- A.Fly
- B.Walk without slipping
- C.Float
- D.Swim
12.
We tend to slip on a wet floor because it has:
- A.Too much friction
- B.Very little friction
- C.No surface
- D.High pressure
13.
Friction makes writing possible because it lets a pencil:
- A.Float above paper
- B.Leave marks on paper
- C.Melt
- D.Stay dry
14.
Grooves and treads on tyres are used to:
- A.Reduce friction
- B.Increase friction (grip)
- C.Remove the tyre
- D.Add weight
15.
Spreading sand on an icy road helps by:
- A.Reducing friction
- B.Increasing friction
- C.Melting the ice instantly
- D.Removing the road
16.
Which of these is a disadvantage of friction?
- A.It lets us walk
- B.It causes wear and tear
- C.It helps braking
- D.It helps writing
17.
Friction between rubbing surfaces produces:
- A.Light only
- B.Heat
- C.Sound only
- D.Electricity
18.
Applying oil or grease between surfaces to reduce friction is called:
- A.Streamlining
- B.Lubrication
- C.Polishing
- D.Welding
19.
Ball bearings reduce friction by changing sliding friction into:
- A.Static friction
- B.Rolling friction
- C.More sliding friction
- D.Heat
20.
Giving a vehicle a smooth, tapered shape to reduce fluid friction is called:
- A.Lubrication
- B.Streamlining
- C.Polishing
- D.Braking
21.
The resistance a fluid offers to an object moving through it is called:
- A.Static friction
- B.Fluid friction (drag)
- C.Rolling friction
- D.Pressure
22.
As the speed of an object through a fluid increases, the drag on it:
- A.Decreases
- B.Increases
- C.Stays the same
- D.Becomes zero
23.
Giving an object a smooth, tapered shape to reduce drag is called:
- A.Lubrication
- B.Streamlining
- C.Polishing
- D.Braking
24.
Aeroplanes and fast trains are streamlined mainly to:
- A.Increase drag
- B.Reduce fluid friction (drag)
- C.Add weight
- D.Increase friction with rails
25.
Which of these is a naturally streamlined animal?
- A.Elephant
- B.Fish
- C.Hippopotamus
- D.Tortoise
Answer Key
Section A — Multiple Choice (1 mark each)
- (B) Opposes relative motion
- (B) Roughness
- (B) Sliding friction
- (C) Rolling
- (B) Static > sliding > rolling
- (B) Pressing them together
- (B) More
- (B) More
- (B) Decreases
- (B) Little
- (B) Walk without slipping
- (B) Very little friction
- (B) Leave marks on paper
- (B) Increase friction (grip)
- (B) Increasing friction
- (B) It causes wear and tear
- (B) Heat
- (B) Lubrication
- (B) Rolling friction
- (B) Streamlining
- (B) Fluid friction (drag)
- (B) Increases
- (B) Streamlining
- (B) Reduce fluid friction (drag)
- (B) Fish
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