# MCQ Questions for Class 11 Physics Chapter 5 Laws of Motion with Answers

Do you need some help in preparing for your upcoming Class 11 Physics exams? We’ve compiled a list of MCQ on The Laws of Motion Class 11 MCQs Questions with Answers to get you started with the subject. You can download NCERT MCQ Questions for Class 11 Physics Chapter 5 Laws of Motion with Answers Pdf free download, and learn how smart students prepare well ahead with MCQ Questions for Class 11 Physics with Answers.

## Laws of Motion Class 11 MCQs Questions with Answers

Solving the Laws of Motion Multiple Choice Questions can help you understand the concepts better.

Question 1.
A body is sliding down a rough inclined plane which makes an angle of 30 degree with the horizontal. If the co-efficient of friction is 0.26, the acceleration in m/s² is
(a) 1.95
(b) 2.78
(c) 3.47
(d) 4.6

Question 2.
Two forces 6 N and 8 N act at a point O. If the angle between the lines of action of the force is 90°, then their resultant is
(a) 14 N
(b) 12 N
(c) 10 N
(d) 48 N

Question 3.
A body of mass 15 kg moving with a velocity of 10 m/s has its velocity reduced to 6 m/s in two seconds. The force that produced this change in velocity is
(a) 60 N
(b) 30 N
(c) 45 N
(d) 20 N

Question 4.
The frame of reference attached to a satellite of the earth is
(a) an inertial frame
(b) an absolute frame at rest with respect to the stars
(c) a non – inertial frame
(d) a gravitational frame

Answer: (c) a non – inertial frame

Question 5.
A machine gun fires a bullet of mass 40 g with a velocity of 1200 ms-1. The man holding it can exert a maximum force on 144 N on the gum. How many bullets can he fire per second at the most?
(a) one
(b) four
(c) two
(d) three

Question 6.
A block of mass M is placed on a flat surface. A force is applied to move it parallel to the surface. The frictional force f developed is proportional to the
(a) square of the mass of the body
(b) mass of the body
(c) reciprocal of the mass of the body
(d) reciprocal of the square of the body

Answer: (b) mass of the body

Question 7.
A passenger in a moving bus is thrown forward when the bus is suddenly stopped. This is explained
(a) by Newtons first law
(b) by Newtons second law
(c) by Newtons third law
(d) by the principle of conservation of momentum

Answer: (a) by Newtons first law

Question 8.
A rocket with a lift-off mass of 3.5 × 10 kg is blasted upwards with an acceleration of 10 m/s². The initial thrust of the blast is (take g = 10 m/s²)
(a) 1.75 × 105N
(b) 3.5 × 105N
(c) 7.0 × 105N
(d) 14 .0 × 105N

Projectile motion calculator finds the initial and final velocity, initial and final height, maximum height, the horizontal distance

Question 9.
A gun of mass 1000 kg fires a projectile of mass 1 kg with a horizontal velocity of 100 m/s. The velocity of recoil of the gun in the horizontal direction is
(a) 5 m/s
(b) 0.1 m/s
(c) 15 m/s
(d) 20 m/s

Question 10.
A spring balance is attached to the ceiling of a lift. A man hangs his bag on the spring and the spring reads 49 N, when the lift is stationary. If the lift moves downwards with an acceleration of 5 m/s, the reading of the spring balance will be
(a) 15 N
(b) 24 N
(c) 49 N
(d) 74 N

Question 11.
A block of mass M is placed on a flat surface. A force is applied to move it parallel to the surface. The frictional force f developed is proportional to the
(a) square of the mass of the body
(b) mass of the body
(c) reciprocal of the mass of the body
(d) reciprocal of the square of the body

Answer: (b) mass of the body

Question 12.
A force of 12 N acts on a body of mass 2 kg. The acceleration produced on the body is
(a) 24 m/s²
(b) 6 m/s²
(c) 14 m/s²
(d) 10 m/s²

Question 13.
The mass of a body is 2 kg. It weight is
(a) 19.6 N
(b) 20 N
(c) 30 N
(d) 40 N

Question 14.
A gun of mass 1000 kg fires a projectile of mass 1 kg with a horizontal velocity of 100 m/s. The velocity of recoil of the gun in the horizontal direction is
(a) 5 m/s
(b) 0 .1 m/s
(c) 15 m/s
(d) 20 m/s

Question 15.
A body of mass 15 kg moving with a velocity of 10 m/s has its velocity reduced to 6 m/s in two seconds. The force that produced this change in velocity is
(a) 60 N
(b) 30 N
(c) 45 N
(d) 20 N

Question 16.
A heavy uniform chain lies on horizontal table top. If the coefficient of friction between the chain and the table surface is 0.25, then the maximum fraction of the length of the chain that can hang over the edge of the table is
(a) 20%
(b) 25%
(c) 30%
(d) 35%

Question 17.
A body is sliding down a rough inclined plane which makes an angle of 30 degree with the horizontal. If the co-efficient of friction is 0.26, the acceleration in m/s² is
(a) 1.95
(b) 2.78
(c) 3.47
(d) 4.6

Question 18.
The mass of a body which is equal to the ratio of the force acting on a body to the acceleration produced in the body is
(a) the gravitational mass
(b) the electromagnetic mass
(c) the internal mass
(d) the inertial mass

Question 19.
A machine gun fires a bullet of mass 40 g with a velocity of 1200 ms-1. The man holding it can exert a maximum force on 144 N on the gum. How many bullets can he fire per second at the most?
(a) one
(b) four
(c) two
(d) three

Question 20.
A passenger in a moving bus is thrown forward when the bus is suddenly stopped. This is explained
(a) by Newtons first law
(b) by Newtons second law
(c) by Newtons third law
(d) by the principle of conservation of momentum