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 12 of 38
- A. ∞
- B. θ
- C. β
- D. α
Explanation: Face β is opposite to δ because it is adjacent to α and not visible in the first cube view. Thus, it is not adjacent to δ in any view.
Correct answer: β- A. A
- B. B
- C. C
- D. D
Explanation: By creating a table and filling in the known cards for each player, we can use a process of elimination to determine the remaining card…
Correct answer: A- A. 45°
- B. 90°
- C. 180°
- D. 0 degree
Explanation: (a) Incorrect. While 45° provides a decent amount of work, it's not the maximum.(b) Incorrect.
Correct answer: 0 degree- A. (a) electric fied
- B. conservative field
- C. electromagnetic field
- D. gravitational field
Explanation: (a) Incorrect. Work can be done in electric fields, especially if the path is not closed.(b) Correct!
Correct answer: conservative field225. When a force is perpendicular to the direction of motion of the body, then work done on the body is:
- A. zero
- B. minimum
- C. infinity
- D. maximum
Explanation: (a) Correct! If the force is perpendicular (θ = 90°) to the displacement, the work done is W = Fd cos θ = 0.(b) Not always true.
Correct answer: zero- A. frictional force
- B. gravitational force
- C. elastic force
- D. centripetal force
Explanation: (a) Not necessarily. Frictional force can do work against the direction of motion, like when slowing down a car.(b) Not true.
Correct answer: centripetal force- A. 38.2 J
- B. 392j
- C. 39.2 J
- D. 3.92 J
Explanation: Reasoning: Work done (W) = Fd cos θ, where F is the force, d is the displacement, and θ is the angle between them.
Correct answer: 39.2 J- A. any rate
- B. variable rate
- C. uniform rate
- D. high rate
Explanation: Reasoning: Average power (P) = W/t and instantaneous power is the rate of work done at any given moment.
Correct answer: uniform rate- A. Proton
- B. Electron
- C. Neutron
- D. Alpha particle
Explanation: Explanation: Kinetic energy (KE) is given by KE = 1/2 mv², where m is mass and v is velocity.
Correct answer: Electron- A. 3 j
- B. 120 j
- C. 720 j
- D. 430 j
Explanation: Explanation: Power (P) is the rate of energy transfer, measured in Joules per second (J/s).
Correct answer: 720 j- A. force into small intervals
- B. displacement into small intervals
- C. both force and displacement into small intervals
- D. force into small and displacement into large intervals
Explanation: Explanation: To calculate the work done by a variable force over a finite distance, we need to account for the changes in both force and…
Correct answer: both force and displacement into small intervals- A. the mass of the object
- B. the angle at which it is thrown
- C. both its mass and the angle at which it is thrown
- D. the gravitational field of Earth
Explanation: Explanation: Escape velocity is the minimum speed an object needs to reach to overcome Earth's gravity and escape its gravitational pull…
Correct answer: the angle at which it is thrown- A. once
- B. twice
- C. four times
- D. eight times
Explanation: Explanation: Tides are caused by the combined gravitational pull of the Moon and the Sun on the Earth's oceans.
Correct answer: twice- A. decay of radioactive elements in the earth
- B. compression of material in the earth
- C. residual heat of the Earth
- D. all as said in a, b and c
Explanation: Explanation: Geothermal energy comes from the Earth's internal heat, which is primarily generated from the decay of radioactive elements…
Correct answer: residual heat of the Earth- A. Earth
- B. Neptune
- C. Jupiter
- D. Moon
Explanation: Correct Answer: (c) JupiterExplanation: Escape velocity is the minimum speed needed for an object to escape a planet's gravitational pull.
Correct answer: Jupiter- A. always positive
- B. always negative
- C. positive only for small frictional force
- D. positive only for large frictional force
Explanation: Correct Answer: (b) always negativeExplanation: Friction is a non-conservative force, meaning it dissipates energy as heat.
Correct answer: always negative- A. Gm/r
- B. mgh
- C. -Gm/r
- D. both "b" and "c"
Explanation: Correct Answer: (b) mghExplanation: Gravitational PE depends on the mass of the object (m), the acceleration due to gravity (g), and the…
Correct answer: mgh- A. momentum and K.E both remain the same
- B. momentum increases to 2 times and K.E remains the same
- C. momentum remains the same and K.E increases to 2 times
- D. momentum increases to 2 times and K.E increases to 4 times
Explanation: Correct Answer: (d) momentum increases to 2 times and K.E increases to 4 timesExplanation:Momentum (p) is directly proportional to…
Correct answer: momentum increases to 2 times and K.E increases to 4 times- A. 3.6 x 10⁶ J
- B. 3.6 x 10¹² J
- C. 3.6 x 10⁸ J
- D. 3.6 x 10⁹ J
Explanation: Correct Answer: (d) 3.6 x 10⁹ J Explanation:1 MW = 10⁶ watts1 Wh = 1 watt-hour = 3.6 x 10³ JTherefore, 1 MWh = 10⁶ Wh x 3.6 x 10³ J/Wh =…
Correct answer: 3.6 x 10⁹ J- A. 0 j
- B. 90 j
- C. 60 j
- D. 40 j
Explanation: Correct Answer: (a) 0 J Explanation:Work (W) = F x dWhile the boy exerts force (40 N), the weight doesn't move any distance (d = 0), so W…
Correct answer: 0 j