Home › Practice › Class 11 › Physics
Laws of Motion MCQs
Class 11 Physics — questions with answers and worked explanations.
20 free questions
Class 11 Physics
Answers + explanations
No sign-up
These questions are drawn from the Pariksha Sutra question bank for Laws of Motion,
part of the Class 11 Physics syllabus. Each one shows the correct answer and,
where a method helps, the working behind it.
Read the question, decide your answer before looking, then check the explanation — that is what turns practice
into marks. If a question catches you out, the explanation is the part worth re-reading.
Questions
Question 1
Newton's first law of motion is also known as the law of:
- Inertia
- Gravitation
- Acceleration
- Interaction
Question 2
A block of weight 50 N slides on a floor with coefficient of kinetic friction 0.2. The kinetic friction force is:
- 250 N
- 10 N
- 2.5 N
- 0.4 N
Question 3
A body's momentum changes from 5 kg m/s to 15 kg m/s in 2 s. The average force is:
- 2.5 N
- 10 N
- 20 N
- 5 N
Question 4
The SI unit of force, the newton, is equivalent to:
- kg m^2/s^2
- kg m/s^2
- kg m/s
- kg/s
Question 5
Two blocks 2 kg and 3 kg connected by a string are pulled by 10 N (2 kg block leading). The tension in the string is:
- 2 N
- 6 N
- 10 N
- 4 N
Question 6
The maximum static friction force is given by:
- mu_s mg only
- mu_s N
- mu_k N
- N/mu_s
Question 7
In a lift accelerating downward at g, the apparent weight of a body is:
- Zero
- mg
- mg/2
- 2mg
Question 8
Linear momentum is a:
- Vector quantity
- Unit vector
- Dimensionless quantity
- Scalar quantity
Question 9
Two blocks of 2 kg and 3 kg connected by a string are pulled by 10 N on a frictionless surface. Their acceleration is:
- 10 m/s^2
- 2 m/s^2
- 5 m/s^2
- 1 m/s^2
Question 10
The dimensional formula of impulse is:
- [M L T^-2]
- [M L^2 T^-2]
- [M L T]
- [M L T^-1]
Question 11
According to Newton's second law, the net force on a body equals:
- Rate of change of acceleration
- Rate of change of displacement
- Rate of change of momentum
- Product of mass and velocity
Answer: Rate of change of momentum
Question 12
For a body in uniform circular motion, the net force is directed:
- Away from the centre
- Zero
- Along the tangent
- Towards the centre
Answer: Towards the centre
Question 13
A cricketer draws his hands back while catching a ball to:
- Decrease the time of contact
- Increase the impulse
- Increase the momentum
- Increase the time of contact and reduce the force
Answer: Increase the time of contact and reduce the force
Question 14
A block does not move despite an applied horizontal force less than the limiting friction. The static friction equals:
- The weight of the block
- Zero
- The applied force
- The limiting friction
Answer: The applied force
Question 15
A block of mass m rests on a frictionless incline of angle theta. The normal reaction is:
- mg
- mg cos theta
- mg sin theta
- mg tan theta
Question 16
A net force of 20 N acts on a 4 kg block on a frictionless surface. Its acceleration is:
- 80 m/s^2
- 4 m/s^2
- 5 m/s^2
- 0.2 m/s^2
Question 17
The angle of banking theta for a curve of radius r at speed v (ignoring friction) satisfies:
- cos theta = v^2/(r g)
- sin theta = v^2/(r g)
- tan theta = r g/v^2
- tan theta = v^2/(r g)
Answer: tan theta = v^2/(r g)
Question 18
A 3 kg body moving at 4 m/s collides and sticks to a 1 kg body at rest. Their common velocity is:
- 3 m/s
- 12 m/s
- 4 m/s
- 1 m/s
Question 19
A block just stays at rest on an incline of angle theta. The coefficient of static friction equals:
- cos theta
- sin theta
- tan theta
- 1/tan theta
Question 20
The component of gravity acting along a frictionless incline of angle theta on mass m is:
- mg sin theta
- mg cos theta
- mg tan theta
- mg/sin theta
30 more questions on this chapter
The full chapter test is timed, gives an All-India rank and a subject-wise breakdown of where you lost marks.
See the test series →
Other chapters