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 36 of 38
- A. 1 : 1
- B. 2 : 1
- C. 4 : 1
- D. 1 : 2
Explanation: Correct option is A. Correct option is 1:1
Correct answer: 1 : 1- A. 45-degree
- B. 90 degree
- C. 0-degree
- D. 180 degree
Explanation: Work done is the dot product of force and displacement. Hence,Work done = F d cos θ.Since cos θ is maximum at 0 radians or degrees,the…
Correct answer: 0-degree- A. 20 J
- B. 21 J
- C. 22 J
- D. 23 J
Explanation: Explanation is given below.Small amount of work done dW in giving a small displacement dx is given by dW=x or dW=Fdxcos0∘ or…
Correct answer: 21 J- A. 0 J
- B. 10 J
- C. 45 J
- D. 20 J
Explanation: W=F.SW=(2i+3j+4k) . (5k)W= 4x5 = 20J Options A, B and C are incorrect
Correct answer: 20 J- A. 2000 J
- B. -2000 J
- C. 0 J
- D. 200 J
Explanation: The work done by a force on an object is given: W = F x d x cosθ where: W = work done by the force (in joules, J) F = magnitude of the…
Correct answer: -2000 J- A. It depends on time
- B. It is independent of time
- C. Both of these
- D. None of these
Explanation: The work done on an object is given by the equation: W = Fd cosθ where W is the work done, F is the force applied, d is the displacement…
Correct answer: It is independent of time- A. 11.4 m/s.
- B. 19.6 m/s.
- C. 22.8 m/s.
- D. 9.8 m/s.
Explanation: The problem involves applying the conservation of energy principle. Initially, the disc is at rest at the top of the hill, possessing only…
Correct answer: 19.6 m/s.- A. (P2 t2)/m
- B. (P2 t2)/2m
- C. (P2 t2)/3m
- D. (P2 t2)/4m
Explanation: The kinetic energy of a particle is given by the formula: KE = ½ mv² In this case, the particle is initially at rest, so its initial…
Correct answer: (P2 t2)/2m- A. P.E. = 300 J and K.E. = 180 J
- B. P.E. = 180 J and K.E. = 300 J
- C. P.E. = 230 J and K.E. = 250 J
- D. P.E. = 250 J and K.E. = 230 J
Explanation: Explanation:At point A, P.E = 480 JSince, P.E = mgh 480 = 6 × 10 × h h = 480 / 60 h = 8m above groundAt B, having fallen 3m, height above…
Correct answer: P.E. = 300 J and K.E. = 180 J- A. 5 m/s
- B. 10 m/s
- C. 15 m/s
- D. 20 m/s
Explanation: Given: Distance = S = 5m Acceleration = a = g = 10ms-2 Initial velocity = Vi = 0 ms-1 Final velocity = Vf = ?
Correct answer: 10 m/s- A. 0.15 J
- B. 4.3 J
- C. 4.4 J
- D. 4.6 J
Explanation: Potential Energy Gain:The fish gains potential energy due to its change in height.
Correct answer: 4.6 J- A. 1000 watt
- B. 100 watt
- C. 10 watt
- D. 0.10 watt
Explanation: Power is the amount of energy transferred or converted per unit time.Power = energy / timeGiven that,Work done = 100JTime taken= 10sPower…
Correct answer: 10 watt- A. 20 J
- B. 120 J
- C. 30 J
- D. 0.02 J
Explanation: The energy consumed by a 60-watt bulb in 2 seconds can be calculated using the power formula: P = E/t.
Correct answer: 120 J- A. VI
- B. I2R
- C. V2/R
- D. All of the above
Explanation: The correct answer is D, 'All of the above', because each option provides a valid formula for calculating power in an electrical circuit.
Correct answer: All of the above715. 1KWh= _ J?
- A. 3.6J
- B. 3.6KJ
- C. 3.6MJ
- D. 3.6 GJ
Explanation: C is the correct option since 1 MJ = 10⁶ J, and we calculated 1 kWh = 3.6 × 10⁶ J = 3.6 MJ.
Correct answer: 3.6MJ- A. 25 W
- B. 0.5 W
- C. 0.75 W
- D. 1 W
Explanation: W=2.0N×1.0m=2.0JNext, the time taken to lift the weight is 4 seconds. Now we can find the power:P =work/time=2/4=0.5Watt
Correct answer: 0.5 W- A. 92.5 J
- B. 97.5 J
- C. 65 J
- D. 130 J
Explanation: Explanation:Final Kinetic energy (K.Ef) = 130 JInitial Kinetic energy (K.Ei) = 65 JWorkdone = W = ?As we know that: W = K.Ef - K.Ei = 130…
Correct answer: 65 J- A. -10
- B. +10
- C. -18
- D. +18
Explanation: Work is a scalar quantity and work done is a dot product of force and displacement.The difference between the two pints will be our…
Correct answer: +10- A. 1500 J
- B. 3000 J
- C. 4500 J
- D. 5000 J
- E. 9, 500 J
Explanation: The thermodynamic work done is W = PdVAs dV = 0 for path b to c it will not contribute any work.The work done will come from path a to b…
Correct answer: 4500 J- A. 0°
- B. 60°
- C. 270°
- D. 360°
Explanation: The formula for work done is displacement multiplied by the force in the direction of the displacement thus we incorporate the angle…
Correct answer: 270°