Tag: friction

Quizzes (10) Questions (79)

Questions Related to friction

Multiple choice physics friction increasing and reducing friction advantages and disadvantages of friction merits and demerits of friction and methods to reduce it

The force of friction on a static body ________ , if It is on a rough surface then.

  1. is always zero

  2. may be gravity.

  3. may be zero

  4. both B & C
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The force of friction f is always opposite the direction the object that is moving . If the object would move, then the direction of the force of friction f will be opposite the movement. If the object would not move when there is no friction, then the force of friction is zero.Hence, though the surfaces of the object are rough the force of friction can be zero if the object would not move.

Multiple choice physics friction increasing and reducing friction advantages and disadvantages of friction merits and demerits of friction and methods to reduce it

Powder is used in carrom board for

  1. Increasing friction

  2. Decreasing friction

  3. Decoration

  4. Fragrance
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Answer is B.

The surface well powdered to stay away from harm to board surface due to scratch.It reduces the friction and helps in smoothing of the board and thereby allows the carom coins to go through in that flow which helps in fast play.
Powder is used in carom board for decreasing friction.

Multiple choice physics friction increasing and reducing friction advantages and disadvantages of friction merits and demerits of friction and methods to reduce it

Friction depends upon ................. of surfaces.

  1. mass.

  2. nature of body.

  3. both A & B

  4. none
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Friction depends upon mass and nature of the body of surfaces.
Friction depends partly on the smoothness of the contacting surfaces, a greater force being needed to move two surfaces past one another if they are rough than if they are smooth. However, friction decreases with smoothness only to a degree; friction actually increases between two extremely smooth surfaces because of increased attractive electrostatic forces between their atoms. 
Friction does not depend on the amount of surface area in contact between the moving bodies or (within certain limits) on the relative speed of the bodies. It does, however, depend on the magnitude of the forces holding the bodies together. 
When a body is moving over a horizontal surface, it presses down against the surface with a force equal to its weight, i.e., to the pull of gravity upon it; an increase in the weight of the body causes an increase in the amount of resistance offered to the relative motion of all the surfaces in contact.

Multiple choice physics friction increasing and reducing friction advantages and disadvantages of friction merits and demerits of friction and methods to reduce it

Graphite powder is used in machines to _________.

  1. enhance friction

  2. enhance profit

  3. reduce friction

  4. reduce efficiency
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Graphite powder is used in machines to reduce friction
Graphite is the only non-metal element that is a good conductor of electricity. Crystal structures rarely occur and easily break down. This is the reason for the material's greasy feeling despite being a dry lubricant.

Multiple choice physics friction increasing and reducing friction advantages and disadvantages of friction merits and demerits of friction and methods to reduce it

The substance that helps to ______ friction are called lubricants.

  1. increase

  2. decrease

  3. create

  4. eliminate
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Oils, grease, graphite, etc., are examples of lubricants. These form a thin layer between the two surfaces in contact thus avoiding them from scrubbing directly against each other. This makes the movement smooth and reduces friction.

Multiple choice physics friction increasing and reducing friction advantages and disadvantages of friction merits and demerits of friction and methods to reduce it

Why are the tyres of automobiles grooved?

  1. To improve the design

  2. To increase friction

  3. To make it durable

  4. To make it strong
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

If the tyres of automobiles were smooth, the friction produced would be minimal and thus, it would be difficult to stop or turn the automobile, increasing the risk of accidents. Hence, the tyres are grooved so as to increase the friction between the tyre and the surface of the road.

Multiple choice physics friction increasing and reducing friction advantages and disadvantages of friction merits and demerits of friction and methods to reduce it

Kabaddi players rub their hands with soil so that they can :

  1. make their skin dry

  2. moisture the hands

  3. get a better grip while holding the opponent

  4. soil the opponent
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

By rubbing their hands with soil, they make their hands rough. A rough surface has more friction which enhances their grip while holding the opponent.

Multiple choice physics friction increasing and reducing friction advantages and disadvantages of friction merits and demerits of friction and methods to reduce it

Which of the following are done to reduce friction?
a) Making grooves in the shoes
b) Polishing rough surfaces
c) Using wheels, ball bearings
d) Creating an air cushion

  1. a, b and c

  2. c and d

  3. b, c and d

  4. All of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
Making grooves in the shoes increases friction.
Polishing rough surfaces makes it smooth, thus reducing friction. 
Wheels and ball bearings create rolling friction which has the least magnitude compared to sliding and static friction.
Air cushion makes a layer of air between two surfaces, which helps in reducing friction.
Multiple choice physics friction increasing and reducing friction advantages and disadvantages of friction merits and demerits of friction and methods to reduce it

How do brake pads help in stopping an automobile?

  1. Brake pads press on the wheel and increase friction.

  2. Due to braking, the air pressure increases and the wheels stop.

  3. Both A and B

  4. None of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The brake pads press on the wheels and increase the friction since the surface of the brake pads and the wheels are irregular, and the rough surface increases friction that opposes the motion of the wheel.