Science - Friction
Exam Duration: 45 Mins Total Questions : 30
What type of a force is friction?
- (a)
Contact force
- (b)
Non-contact force
- (c)
Electrostatic force
- (d)
Magnetic force
Which of the following materials is likely to have the least friction?
- (a)
Wood
- (b)
Cardboard
- (c)
Glass
- (d)
Paper
Which of the following reduces friction in a rotating machine?
- (a)
Wheels
- (b)
Rollers
- (c)
Ball bearings
- (d)
Handle
In which of the following cases is friction desirable?
- (a)
Movement of piston in a cylinder
- (b)
A vehicle speeding
- (c)
Running on a track
- (d)
All of the above
Why is a carrom board usually powdered before playing?
- (a)
For increasing friction
- (b)
For decreasing friction
- (c)
For decoration
- (d)
For fragrance
Which of the following statements is correct?
- (a)
Rolling is easier than sliding.
- (b)
Sliding is easier than rolling.
- (c)
Dragging is easier than sliding.
- (d)
Dragging is easier than rolling.
What is the frictional force exerted by fluids called?
- (a)
Lift
- (b)
Drag
- (c)
Rolling friction
- (d)
Dynamic Friction
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
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
Why are the head of a match stick and the sides of a match box deliberately made rough?
- (a)
To increase friction
- (b)
To decrease friction
- (c)
To increase the amount of heat
- (d)
To decrease the amount of heat
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
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
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.
Which of the following is a disadvantage of friction?
- (a)
It enables the brakes of a car to work
- (b)
It allows us to hold a pen
- (c)
It helps us to sandpaper a table
- (d)
It wears out our shoes
Which of the following is NOT an effect of frictional force?
- (a)
The grooves of tyres flattened due to use
- (b)
A rolling ball coming to a halt
- (c)
Leaves falling from a tree
- (d)
The holding of a pencil
Why are tyres made circular in shape?
- (a)
It is easy to inflate circular tyres.
- (b)
Rolling friction is less than sliding friction.
- (c)
Circular tyres dissipate less heat.
- (d)
Circular tyres easily slow down or stop a vehicle.
Sudhakar's bicycle was making a lot of squeaking noise. What should he do to stop the squeaking noise?
- (a)
Water
- (b)
Oil
- (c)
Sand
- (d)
Powder
While walking on ice, why should one take small steps to avoid slipping?
- (a)
Smaller steps ensure larger friction
- (b)
Smaller steps ensure smaller friction
- (c)
Smaller steps ensure larger distance covered
- (d)
Smaller steps ensure smaller distance covered
How can friction be decreased?
- (a)
By using smooth surfaces
- (b)
By using dry surfaces
- (c)
By increasing the weight of the body
- (d)
All of the above
Which of the following activities will not be possible in the absence of friction?
- (a)
Holding a glass
- (b)
Writing on a paper
- (c)
Sitting on a chair
- (d)
All of the above
Which of the following is reduced by the correct measure of air pressure in the tyres?
- (a)
Static friction
- (b)
Sliding friction
- (c)
Rolling friction
- (d)
All of the above
Which of the following makes it difficult to quickly stop a ship moving in a sea by applying brakes?
- (a)
Low friction
- (b)
Excess friction
- (c)
High speed
- (d)
External force
Why do the soles of our shoes easily wear out?
- (a)
Due to the difference in the material of the sole
- (b)
Due to poor design
- (c)
Due to friction
- (d)
Due to their size
Harish rolled a small steel ball at one edge of the glass bowl as shown below,
If there is no friction between the surfaces of the ball and the bowl, what will happen to the ball?
- (a)
The ball will roll out of the glass bowl near edge 'Q'.
- (b)
It will stop at centre point 'R' after a number of to-and-fro motions.
- (c)
It will keep moving between point 'P' and 'Q' and will never stop.
- (d)
It will not move at all since friction is required for movement.
When does a body have zero force of friction?
- (a)
When no force is applied on a body at rest
- (b)
When a large force is applied on a body
- (c)
When a body is rolling on the surface
- (d)
When a body is sliding on the surface
Look at the figure given below.
Which of the following forces is necessary for a person to climb the mountain?
- (a)
Gravitational force
- (b)
Electrical force
- (c)
Frictional force
- (d)
Magnetic force
Observe the figure given below.
Identify X and Y.
- (a)
X Y Motion Weight - (b)
X Y Motion Friction - (c)
X Y Friction Weight - (d)
X Y Weight Motion
Anoop and Sohail while studying about friction decided to perform an experiment. They placed equal masses of an ice block and sand paper block on an inclined plastic tray as shown below.
What happens when both the blocks start moving?
- (a)
Ice block reaches the bottom of the tray first.
- (b)
Sand paper block reaches the bottom of the tray first.
- (c)
Both the blocks reach the bottom of the tray at the same time.
- (d)
Both the blocks offer the same amount of friction.
In which of the following does friction playa helpful role?
(i) Striking a match stick
(ii) Playing snooker
(Hi) Writing on the blackboard
- (a)
Only (i) and (ii)
- (b)
Only (ii) and (iii)
- (c)
Only (i), and (iii)
- (d)
(i), (ii) and (iii)
Which of the following shows that friction exists between the two bodies?
- (a)
When the movement is decreased or prevented
- (b)
When there is a constant movement
- (c)
When electromagnetic charges are produced
- (d)
When there is a constant increase in weight