Free Work and Energy MCQs with Answers
748 Work and Energy MCQs from Physics, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Work transfers energy when a force causes displacement, while kinetic energy, gravitational potential energy and power describe motion, position and the rate of energy transfer. The work-energy theorem links net work with change in kinetic energy, and efficiency accounts for energy losses rather than treating them as energy destruction.
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Read the Work and Energy notesFree MDCAT chapter notes with key terms748 questions · page 30 of 38
- A. Maximum
- B. Zero
- C. Minimum
- D. Negative
Explanation: This is correct because W = F·d·cosθ; when θ = 90°, cosθ = 0 ⇒ W = 0.
Correct answer: Zero- A. Nm
- B. kg·m²/s²
- C. J
- D. W
Explanation: This is correct because watt is the unit of power, not energy. Power is the rate of doing work.
Correct answer: W- A. 9:4
- B. 3:2
- C. 4:9
- D. 2:3
Explanation: Formula for kinetic energy is given as ½ mv2. As the masses are the same so, the kinetic energy will be in the ratios of the square of…
Correct answer: 4:9- A. 1/2
- B. 1/4
- C. 1/8
- D. 1/6
Explanation: If the speed is halved (keeping the mass same), the kinetic energy decreases, it becomes one-fourth (since kinetic energy is proportional…
Correct answer: 1/4- A. Mv2
- B. 2mv2
- C. ½ mv2
- D. 4mv2
Explanation: If the speed of a body is doubled, its kinetic energy becomes four times its original value.
Correct answer: 2mv2- A. 2 time increased
- B. 2 time decreased
- C. 4 time decreased
- D. 4 time increased
Explanation: Kinetic energy is proportional to the square of velocity, so if velocity doubles, K.E increases 4 times.
Correct answer: 4 time increased- A. 10 J
- B. 0 J
- C. 200 J
- D. 1000 J
Explanation: m=1kg h=10m v=14m/sK.Ef = K.Ei + loss in GP.EK.Ef = 1/2mv2 + m.g.hK.Ef = ½ (1)(14)2 + (1)(10)(10)K.Ef = (0.5)(196) + 100K.Ef =…
Correct answer: 200 J- A. 125 J
- B. 250 J
- C. 500 J
- D. 255 J
Explanation: m=10 kgv=5 ms^-1Kinetic energy K.E= ½ mv^2 K.E= ½ [10][5]^2 K.E= 5*25 K.E= 125 J
Correct answer: 125 J- A. 200 %
- B. 300 %
- C. 400 %
- D. 800 %
Explanation: Momentum P = mv Kinetic energy K.E= 1 /2 mv^2 K.E= p^2/ 2mIf p is increased vy 200% ,then new p will be.
Correct answer: 800 %- A. 100 J
- B. 1000 J
- C. 10 J
- D. none of these
Explanation: Kinetic energy = ½ mv^2 Mass = 5x10^-5 Velocity = 200 K.E = ½ (5x10^-5) (200^2) K.E = ½ (0.00005) (40000) K.E= 2/2 K.E= 1 Since the answer…
Correct answer: none of these- A. 1 J
- B. 3 J
- C. 30 J
- D. 2 J
Explanation: Work done to stop the disc = change in total kinetic energy of disc Final KE = 0 Initial KE = Translational K.E + Rotational K.EInitial…
Correct answer: 3 J- A. 1J
- B. 2J
- C. 3J
- D. 4J
Explanation: The Kinetic Energy is related to Momentum as;K.E. = P²/2mBy substituting values of 'P' and 'm' into the equation, we get;K.E.
Correct answer: 1J- A. 0.44
- B. 0.55
- C. 0.66
- D. 0.77
Explanation: If momentum is increased by 20%, then the kinetic energy increases by 44% or 0.44 The kinetic energy of an object is given by the equation…
Correct answer: 0.44- A. increases 4 times
- B. increases 6 times
- C. increases 8 times
- D. increases 10 times
Explanation: The kinetic energy of an object is given by the formula: KE = ½ mv²If both mass (m) and speed (v) are doubled, the new kinetic energy…
Correct answer: increases 8 times- A. 30J
- B. 55J
- C. 50J
- D. 22.5J
Explanation: Correct Option:DThis option is correct because we know from the formula of kinetic energyK.E=1/2mv²...(1)From the formula of momentum, we…
Correct answer: 22.5J- A. 200%
- B. 300%
- C. 400%
- D. 800%
Explanation: Kinetic Energy can also be expressed as p2/2m. Hence, KE is directly proportional to the square of momentum.
Correct answer: 800%- A. 0.44
- B. 0.55
- C. 0.66
- D. 0.77
Explanation: The increase in momentum is given as 20%, which can be expressed as a factor of 1.2.
Correct answer: 0.44- A. Insufficient information
- B. 10 m/s
- C. 100 m/s
- D. 20 m/s
Explanation: We shall need to assume that friction and air resistance are to be ignored.
Correct answer: 10 m/s- A. 2E
- B. 4E
- C. 6E
- D. 10E
Explanation: E = ½ kx2 E= ½ k(0.1)2 For second situation, E'= ½ kx'2 E'= ½ k(0.2)2 Comparing E and E', we get E'= 4E
Correct answer: 4E- A. Kinetic energy
- B. Potential energy
- C. Gravitational potential energy
- D. Absolute potential energy
Explanation: The work done in moving a body from a certain point in a gravitational field to a position of zero potential without acceleration is…
Correct answer: Gravitational potential energy