Frictional Force

Q. Why is powder sprinkled on the carrom board while playing carrom?

1. To increase the brightness of the surface of the carrom board.
2. To make the surface of the carrom board rough.
3. To decrease the distance covered by the carrom coins.
4. To reduce the friction of the carrom board.

Q.

We are likely to slip while walking on a wet floor. What is the reason behind this?

1. Decrease in friction

2. Increase in friction

3. Increase in weight of the body

4. Decrease in weight of the body

Q. Friction always opposes the direction of motion of an object.

1. False
2. True

Q. Whenever the surfaces in contact tend to move or move with respect to each other, the force of friction comes into play. This happens ___.

1. only if the objects are solid
2. only if one of the two objects is liquid
3. only if one of the two objects is gaseous
4. irrespective of whether the objects are solids, liquids or gases

Q. Sprinkling of powder on the carrom board ___ friction.

1. Decreases
2. Increases
3. Has no effect on
4. Can’t say

Q. A speeding car will stop if the brakes are applied, even if there is no friction.

1. True
2. False

Q.

Force acts on an object may change

Q. Question 4
A toy car released with the same initial speed will travel farthest on

(a) muddy surface
(b) polished marble surface
(c) cemented surface
(d) brick surface

Q. Friction can be reduced on a road by _______.

1. making the surface wet

2. making the surface dry

3. sprinkling sand on the surface

4. making the surface rubbery

Q. 'A machine is 75% efficient'. What do you understand by this statement?

Q.

A meteor starts burning when it enters Earth's atmosphere. Which of the following correctly explains this?

1. Gravitational force produces heat.

2. Frictional force produces heat.

3. Magnetic force produces heat.

4. Electrostatic force produces heat.

Q. Which of the following statement is incorrect?

1. Friction acts on a boat moving on water.
2. Friction acts on a bicycle moving on a road.
3. Friction does not act on a ball moving through air.
4. Friction acts on a ball rolling along the ground.

Q. A ball rolling on ground comes to rest by itself after a while. Which force opposes its motion?

1. Gravitational Force
2. Frictional force
3. Magnetic Force
4. Muscular force

Q. Frictional force between two surfaces can be increased or decreased by making the surfaces rougher or smoother.

1. True
2. False

Q.

You might have noticed that when used for a long time, slippers with rubber soles become slippery. Explain the reason.

Q.

Is friction an impulsive force?

Q.

Iqbal has to push a lighter box and Seema has to push a similar heavier box on the same floor. Who will have to apply a larger force and why?

Q. If a box is moving rightwards on a rough horizontal floor, then what is the direction of friction acting on the box?

1. Leftwards
2. Rightwards
3. Upwards
4. Downwards

Q.

Name three different types of forces?

Q. A block sliding on a horizontal rough surface comes to rest after travelling some distance on it. The force which is responsible for stopping the block is:

1. Gravitational force
2. Magnetic force
3. Electrostatic force
4. Frictional force

Q. Humans are able to walk and hold objects in hands because of _______.

1. magnetic force
2. gravitational force
3. mechanical force
4. frictional force

Q. Which type of force helps in making grip on an object?

1. Frictional force
2. Gravitational force
3. Electrostatic Force
4. Magnetic force

Q.

Which of the following statements are correct about the force of friction?

1. It acts on all moving objects.

2. It opposes the relative motion between two objects in contact with each other.

3. It is a contact force.

1. 1 and 3

2. 2, 3 and 4

3. All of the above

4. 1, 3 and 4

Q. A ball rolled along a horizontal surface, comes to stop after some time. force is responsible for stopping the ball.

1. Gravitational
2. Nuclear
3. Frictional
4. Electrostatic

Q. A ball is rolled on the sand, on road, and on an ice surface. On it will move the farthest.

1. sand
2. road
3. ice

Q. What is the value of frictional force acting on body, when no external force is acting on the body?

1. $>0$
2. $0$
3. Either $>0$ or $<0$
4. $<0$

Q.

Friction does not depend on the nature of the surface in contact.

1. True
2. False

Q. Which of the following methods cannot be used to increase friction?

1. Polishing the surfaces
2. Using dry surfaces
3. Increasing weight of the body
4. Using lubricants like oil and grease

Q. What are the forces of cohesion and adhesion?

Q. What kind of forces are involved with the character shown below while hanging upside down?

1. Muscular force
2. Gravitational force
3. Frictional force
4. Electrostatic force