Work Energy and Power Practice Questions
JEE · Physics · 1413 free MCQs with instant results and detailed explanations.
1413
Total
332
Easy
564
Medium
517
Hard
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Topics in Work Energy and Power
Power
179
Collisions
432
Conservation of Energy
262
Work-Energy Theorem
213
Variable Force Problems
327
Sample Questions from Work Energy and Power
Here are 10 sample questions. Start a quiz to get randomized questions with scoring.
Q1
Easy
If 200 J of work is done to lift a mass of 10 kg to a height of 'h', what is the height 'h'?
A.
2 m
B.
3 m
C.
4 m
D.
5 m
Show Answer & Explanation
Correct Answer: A
Using the work-energy principle, Work = mgh, we rearrange to find h = Work/(mg) = 200 J / (10 kg * 9.8 m/s²) â 2 m.
Q2
Easy
A car accelerates from rest to a speed of 20 m/s. If its mass is 1000 kg, what is the kinetic energy gained by the car?
A.
200 kJ
B.
300 kJ
C.
400 kJ
D.
500 kJ
Show Answer & Explanation
Correct Answer: A
Kinetic energy (KE) is given by KE = 1/2 mv². Here, KE = 1/2 * 1000 kg * (20 m/s)² = 200 kJ.
Q3
Easy
A cyclist does 300 J of work to climb a hill. If the mass of the cyclist is 75 kg, what is the change in height?
A.
1 m
B.
2 m
C.
3 m
D.
4 m
Show Answer & Explanation
Correct Answer: B
Using Work = mgh, we can rearrange to find height h = Work/(mg) = 300 J / (75 kg * 9.8 m/s²) â 2 m.
Q4
Medium
A car of mass 1000 kg accelerates from rest to a speed of 20 m/s. What is the work done by the engine if the car travels 50 m during this acceleration?
A.
200,000 J
B.
400,000 J
C.
100,000 J
D.
150,000 J
Show Answer & Explanation
Correct Answer: A
To find the work done, calculate the change in kinetic energy: KE_final = (1/2) * m * v^2 = (1/2) * 1000 kg * (20 m/s)^2 = 200,000 J. Assuming no other forces are acting, the work done by the engine equals this change in kinetic energy.
Q5
Medium
If a particle moves in a circular path at a constant speed, how does the work done by the net force compare to zero?
A.
Positive work
B.
Negative work
C.
Zero work
D.
Depends on radius
Show Answer & Explanation
Correct Answer: C
In uniform circular motion, the net force acts perpendicular to the displacement, resulting in zero work done.
Q6
Medium
An object gains 100 J of kinetic energy. How much work was done on it?
A.
50 J
B.
100 J
C.
150 J
D.
200 J
Show Answer & Explanation
Correct Answer: B
According to the work-energy theorem, the work done on an object is equal to its change in kinetic energy.
Q7
Medium
In which case is the work done by a conservative force non-zero?
A.
Moving in a circular path
B.
Lifting an object vertically
C.
Sliding down a frictionless incline
D.
All of the above
Show Answer & Explanation
Correct Answer: B
The work done by a conservative force is non-zero only when there is a height change, such as lifting an object vertically.
Q8
Hard
A body of mass 5 kg is moving with a velocity of 10 m/s. Calculate the work done by a net force that brings the body to rest. What is the work done?
A.
-250 J
B.
250 J
C.
-500 J
D.
500 J
Show Answer & Explanation
Correct Answer: A
The initial kinetic energy is (1/2)mv² = 0.5 * 5 * 10² = 250 J. The work done to bring the body to rest is equal to the negative of the initial kinetic energy.
Q9
Hard
A car accelerates uniformly from rest to a speed of 30 m/s in 10 seconds. If the mass of the car is 1200 kg, what is the work done by the engine during this time?
A.
180000 J
B.
90000 J
C.
360000 J
D.
540000 J
Show Answer & Explanation
Correct Answer: A
The work done is equal to the change in kinetic energy. The final kinetic energy can be calculated using KE = (1/2)mv².
Q10
Hard
An object is lifted vertically against gravity. If a force of 200 N is applied to lift a 15 kg object to a height of 10 m, what is the work done against gravity?
A.
1500 J
B.
2000 J
C.
1000 J
D.
1800 J
Show Answer & Explanation
Correct Answer: B
The work done against gravity is calculated using W = mgh, where g = 9.81 m/s². The total height is considered.
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Work Energy and Power â JEE Physics Practice Questions Online
This page contains 1413 practice MCQs for the chapter Work Energy and Power in JEE Physics. The questions are organized by difficulty â 332 easy, 564 medium, 517 hard â 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.