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 15 of 38
- A. 3
- B. 1/3
- C. 9
- D. 1/9
Explanation: The energy content of food is typically measured in calories. A calorie is a unit of energy.
Correct answer: 1/3- A. Electrical Energy
- B. Thermal Energy
- C. Kinetic Energy
- D. All of these
Explanation: Mechanical energy is the energy associated with the motion and position of an object.
Correct answer: Kinetic Energy- A. increase by 4 times
- B. Decrease by 4 times
- C. First increase then decrease
- D. Remain the same
Explanation: Kinetic energy (KE) is given by the formula:KE = 1/2 * mv^2Where:KE is the kinetic energym is the mass of the objectv is the velocity of…
Correct answer: increase by 4 times- A. +1 J
- B. -1 J
- C. 0 J
- D. Either a or b
Explanation: Work done is given by the dot product of force and displacement:W = F .
Correct answer: +1 J- A. 2.38 km/s
- B. 3.38 km/s
- C. 4.38 km/s
- D. 5.38 km/s
Explanation: Escape velocity is the minimum velocity an object needs to escape the gravitational pull of a celestial body.
Correct answer: 2.38 km/s- A. Positive
- B. Negative
- C. Zero
- D. None of these
Explanation: A retarding force opposes the motion of an object. Work done by a force is given by:W = F * d * cos θWhere:W = Work doneF = Forced =…
Correct answer: Negative- A. 10 watts
- B. 5 watts
- C. 8 watts
- D. 9 watts
Explanation: Power is defined as the rate of doing work.Power = Work Done / TimeWork done is defined as the change in kinetic energy.Work = 1/2 * m *…
Correct answer: 8 watts- A. -20 J
- B. 20 J
- C. 40 J
- D. -40 J
Explanation: Work done is given by the formula:W = F * d * cos(theta)where:W is the work doneF is the forced is the displacementtheta is the angle…
Correct answer: -20 J- A. Gravitational field
- B. Conservative field
- C. Non-conservative field
- D. None of these
Explanation: A conservative force is a force that does not depend on the path taken.
Correct answer: Non-conservative field- A. 37
- B. 61
- C. 25.4
- D. 22.4
Explanation: The escape velocity of a planet is the minimum velocity that an object must have to escape the gravitational pull of the planet.
Correct answer: 61- A. sun
- B. Earth
- C. moon
- D. water
Explanation: Geothermal energy is heat energy from within the Earth. It is a renewable source of energy that can be used to generate electricity or to…
Correct answer: Earth- A. Object moves in the direction of Force
- B. Object moves in opposite direction of Force
- C. Object moves at Right Angle to the Force
- D. Both a and c
Explanation: Work done by a force is defined as the product of the force and the displacement of the object in the direction of the force.
Correct answer: Object moves in the direction of Force293. Power developed by a person on eating 100g of ice per minute is (Latent heat of ice is 80 cal/g):
- A. 130 W
- B. 560 cal/sec
- C. 560 J/sec
- D. None of these
Explanation: Power = (mass per second) × latent heat.m = 100 g / 60 s = 5/3 g/s, so energy rate = (5/3×80) cal/s = 400/3 cal/s.Converting to joules…
Correct answer: 560 J/sec- A. 35 KJ
- B. 55 KJ
- C. 45 KJ
- D. 65 KJ
Explanation: At 'Q' P.E is 50KJ less than P.E at 'P'; at 'P' K.E=5KJ and workdone against friction is 10KJ. ΔU=-50KJ, friction removes10KJ.
Correct answer: 45 KJ- A. 0°
- B. 30°
- C. 60°
- D. 90°
Explanation: Work W = F d cosθ ⇒ cosθ = W/(F d) = 25/(5×10) = 1/2, so θ = arccos(1/2) = 60°.Therefore the force makes a 60° angle with the displacement.
Correct answer: 60°- A. 40 J
- B. 4x2π (10)J
- C. 20 J
- D. Zero
Explanation: In uniform circular motion the centripetal force is always perpendicular to instantaneous displacement, so the instantaneous work done by…
Correct answer: Zero- A. 18J
- B. 9J
- C. 13.5J
- D. 4.5J
Explanation: W= area under the F-x graph; W= 1/2 (sum of parallel sides)(perpendicular distance between parallel sides) = 1/2 (6+3)(3)= 13.5J.
Correct answer: 13.5J298. 1 MWh is equal to:
- A. 3.6 kJ
- B. 3.6 J
- C. 3.6 MJ
- D. 3.6 GJ
Explanation: 1 MWh = 106 W × 3600 s = 3.6×109 J = 3.6 GJ. Thus option D is the correct conversion.
Correct answer: 3.6 GJ- A. Change in K.E
- B. Change in P.E
- C. Change in elastic P.E
- D. All of these
Explanation: Work can change various forms of energy depending on the context; it equals a change in kinetic energy (work-energy theorem) and can also…
Correct answer: All of these- A. Acceleration
- B. Momentum
- C. Power
- D. Work
Explanation: Slope d(E)/dt is the rate of change of energy with time, which by definition is power. Therefore energy‑time graph slope represents power.
Correct answer: Power