Physics

Friction and Inclined Planes

58 Questions

Friction and inclined plane problems focus on calculating forces, coefficients of static and kinetic friction, and motion on rough surfaces. Questions cover blocks on horizontal tables, angled planes, and simple harmonic motion systems. These physics concepts are strictly evaluated in engineering entrance and civil services tests.

Static friction coefficientKinetic friction forceInclined plane blocksDamped vibrations systemHorizontal table motion

Friction and Inclined Planes Questions

Multiple choice general knowledge science & technology

There is a friction force of 10 Newtons between a box and a table top. In order to move the box at a constant velocity, you would have to supply a force of:

  1. 10 Netwons

  2. > 10 Newtons

  3. < 10 Newtons

  4. Nonsense! No force is required to move the box
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

To move at constant velocity (zero acceleration), the applied force must exactly balance the friction force. Since friction = 10 N, the applied force must also be 10 N to achieve net force = 0 (Newton's First Law).

Multiple choice general knowledge

There is a friction force of 10 Newtons between a box and a table top. In order to move that box at constant velocity, you would have to supply a force.

  1. slightly less than 10 newtons.

  2. slightly greater than 10 newtons.

  3. Nonsense! No force is required to move the box.

  4. of 10 Newtons

  5. Cant tell
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

To move the box at constant velocity, the applied force must exactly balance the friction force (10 N). When velocity is constant, acceleration is zero, so net force must be zero according to Newton's second law (F=ma). If you applied slightly more than 10 N, the box would accelerate. Slightly less than 10 N wouldn't overcome friction. Exactly 10 N makes net force zero, maintaining constant velocity.

Multiple choice

Tie a string of spring balance around brick. Pull it with spring balance and note down the reading when brick just begins to move. Now repeat by placing the brick in polythene and then by placing the brick wrapped in a newspaper. In which of the following cases do we get small value of force of friction?

  1. When we pull brick

  2. When we pull brick wrapped in newspaper

  3. When we pull brick wrapped in polythene

  4. Same value in all cases
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

 When we pull brick wrapped in polythene because it reduces force of friction.

Multiple choice

What is the main cause of friction?

  1. Irregularities and interlocking of the two surfaces in contact.

  2. Heat is produced when two surfaces rub each other.

  3. When two surfaces come in contact, they exert pressure on each other which causes friction.

  4. Irregularities on the upper surface only cause friction when two surfaces comes in contact.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Friction arises primarily from microscopic irregularities on both contacting surfaces that interlock and resist sliding. Even apparently smooth surfaces have roughness at the atomic level that creates resistance. Heat (option B) is a RESULT of friction, not a cause. Pressure (option C) affects normal force but not the friction mechanism itself. Option D is incorrect because irregularities on BOTH surfaces contribute to friction.

Multiple choice

Make an inclined plane on a smooth floor. Now put a mark with pen at any point A on the inclined plane. Let the pencil cell moves down from this point and note down distance. Now spread a piece of woollen cloth on the floor and repeat the experiment and note down distance. Now repeat this activity by spreading sand paper over it. In which of the following cases does pencil cell cover maximum distance?

  1. In all cases, distance covered would be same.

  2. When woollen cloth is spread over the floor.

  3. When sand paper is spread on the floor.

  4. When nothing is spread on the floor.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

 When nothing is spread on the floor the force of friction of minimum.

Multiple choice

The formula for the mechanical advantage of an inclined plane is

  1. load arm divided by effort arm

  2. distance divided by height

  3. height divided by distance

  4. effort arm multiplied by load arm

  5. half of the input arm divided by output arm
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The mechanical advantage of an inclined plane is the ratio of the length of the plank to the vertical height of the load raised.

Multiple choice

Three boxes of the same material filled with oil, sand and graphite, respectively have the same weight. The surface area of the box which is filled with oil is larger than the other two. If the three boxes are allowed to push simultaneously, then which of the following statements is true?

  1. Force of friction will be more on the oil box.

  2. Force of friction will remain the same on all boxes.

  3. Force of friction will be more on the sand and graphite box than the oil box.

  4. Force of friction will be more on the sand box only.

  5. Force of friction will be less on the oil box.

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Force of friction will remain the same for all the boxes because friction is independent of the area in contact, its only depends upon weight.

Multiple choice

Which of the following statements is/are false? a. A smaller block moves over a bigger block only when the pulling force applied becomes greater than the force of friction holding them together. b. In case of static friction, the object is not actually moving or sliding over the other object, it only tends to move or slide. c. Force of friction is lesser, if very rough surfaces are involved.

  1. Only a

  2. Only a and b

  3. Only b

  4. Only b and c

  5. Only c
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

This is the correct option, as this statement is false. Force of friction is greater, if very rough surfaces are involved.