Laws of Motion Practice Questions
JEE · Physics · 1396 free MCQs with instant results and detailed explanations.
1396
Total
330
Easy
546
Medium
520
Hard
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Topics in Laws of Motion
Friction
264
Newton's Laws
246
Circular Motion Dynamics
237
Pseudo Forces
370
Constraint Equations
279
Sample Questions from Laws of Motion
Here are 10 sample questions. Start a quiz to get randomized questions with scoring.
Q1
Easy
What does Newton's First Law of Motion state?
A.
An object in motion stays in motion unless acted upon.
B.
Force equals mass times acceleration.
C.
For every action, there is an equal reaction.
D.
The acceleration of an object is directly proportional to the net force.
Show Answer & Explanation
Correct Answer: A
This law explains inertia, the tendency of an object to remain at rest or in uniform motion.
Q2
Easy
Which of the following represents Newton's Third Law of Motion?
A.
Objects in motion stay in motion.
B.
Force is mass times acceleration.
C.
For every action, there is an equal and opposite reaction.
D.
Acceleration is caused by unbalanced forces.
Show Answer & Explanation
Correct Answer: C
Newton's Third Law states that forces always occur in pairs.
Q3
Easy
An object weighing 10 N is on a frictionless surface. What is required to keep it moving at a constant speed?
A.
A force greater than 10 N
B.
A force of 10 N
C.
No force is required
D.
A force of less than 10 N
Show Answer & Explanation
Correct Answer: C
According to Newton's First Law, no force is required to maintain constant speed on a frictionless surface.
Q4
Medium
A block of mass 5 kg is placed on a frictionless inclined plane making an angle of 30ยฐ with the horizontal. What is the acceleration of the block down the incline?
A.
4.9 m/sยฒ
B.
5.0 m/sยฒ
C.
3.0 m/sยฒ
D.
6.1 m/sยฒ
Show Answer & Explanation
Correct Answer: A
The acceleration can be calculated using the formula a = g * sin(ฮธ). With g โ 9.8 m/sยฒ and ฮธ = 30ยฐ, a = 9.8 * 1/2 = 4.9 m/sยฒ.
Q5
Medium
A car of mass 1000 kg is moving with a velocity of 20 m/s. It suddenly applies brakes and comes to rest in 5 seconds. What is the magnitude of the average force applied by the brakes?
A.
4000 N
B.
2000 N
C.
3000 N
D.
5000 N
Show Answer & Explanation
Correct Answer: A
Using impulse-momentum theorem, the change in momentum is equal to the force multiplied by the time. The change in momentum = m(v_f - v_i) = 1000*(0 - 20) = -20000 kgยทm/s. Thus, F = ฮp/t = -20000/5 = -4000 N.
Q6
Medium
A car of mass 1000 kg accelerates from rest to a speed of 25 m/s in 10 seconds. What is the net force acting on the car?
A.
250 N
B.
1000 N
C.
500 N
D.
2000 N
Show Answer & Explanation
Correct Answer: B
First, calculate acceleration: a = (v - u)/t = (25 - 0)/10 = 2.5 m/sยฒ. Now, using F = ma, net force F = 1000 kg ร 2.5 m/sยฒ = 2500 N.
Q7
Medium
A 15 kg object is acted upon by three forces: 10 N to the right, 5 N to the left, and 2 N downwards. What is the net force acting on the object in the horizontal direction?
A.
5 N left
B.
5 N right
C.
7 N right
D.
3 N left
Show Answer & Explanation
Correct Answer: B
Net force horizontally = 10 N (right) - 5 N (left) = 5 N (right). The vertical force does not affect horizontal net force.
Q8
Hard
In a system where three blocks A, B, and C are placed on a frictionless surface, block A (mass 2 kg) exerts a force of 10 N to the right on block B (mass 3 kg), which in turn exerts a force on block C (mass 5 kg) to the right. What is the acceleration of block C?
A.
1 m/sยฒ
B.
2 m/sยฒ
C.
3 m/sยฒ
D.
4 m/sยฒ
Show Answer & Explanation
Correct Answer: B
The total mass of the entire system is the sum of the masses of blocks A, B, and C. The acceleration of the system can be found using F = ma, where F is the total force applied by block A. Thus, a = F / total mass.
Q9
Hard
A particle moves along a straight line under the influence of a constant force. If the particle's velocity changes from 5 m/s to 20 m/s in 10 seconds, what is the magnitude of the force acting on the particle if its mass is 4 kg?
A.
6 N
B.
8 N
C.
12 N
D.
15 N
Show Answer & Explanation
Correct Answer: B
Using Newton's second law, we first find the acceleration using a = (v - u) / t, where v is the final velocity, u is the initial velocity, and t is the time duration. Then we apply F = ma to find the force.
Q10
Hard
Two blocks of masses 3 kg and 6 kg are connected by a light inextensible string over a frictionless pulley. If the 3 kg block is hanging and the system is released from rest, what is the acceleration of the system?
A.
1 m/sยฒ
B.
2 m/sยฒ
C.
3 m/sยฒ
D.
4 m/sยฒ
Show Answer & Explanation
Correct Answer: A
The acceleration can be found using Newton's second law. The net force on the system is the difference in weights of the two blocks. The total mass of the system can be used to find the acceleration.
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Laws of Motion โ JEE Physics Practice Questions Online
This page contains 1396 practice MCQs for the chapter Laws of Motion in JEE Physics. The questions are organized by difficulty โ 330 easy, 546 medium, 520 hard โ so you can choose the right level for your preparation.
Every question includes a detailed explanation to help you understand the concept, not just memorize answers. Take a timed quiz to simulate exam conditions, or practice at your own pace with no time limit. This chapter covers 5 topics, giving you comprehensive coverage of the entire chapter.