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 7 of 38
- A. Upward and its gravitational potential energy increased.
- B. Downward and its gravitational potential energy decreased.
- C. Downward and its gravitational potential energy increased.
- D. Upward and its gravitational potential energy decreased.
- E. None of the above.
Explanation: The correct answer is that the center of gravity moved upward and its gravitational potential energy increased.
Correct answer: Upward and its gravitational potential energy increased.122. As we move up a body, above the surface of Earth, the change in potential energy will always be:
- A. Negative
- B. Zero
- C. Positive
- D. Infinity
Explanation: Option C is correct.The change in potential energy is positive when we move a body upward above the surface of the Earth.
Correct answer: Positive- A. 0 J
- B. 196 J
- C. 4.9 J
- D. 98 J
Explanation: W horizontal = mgh cos 90 = 0W vertical = mgh = (1)(9.8)(10) = 98 JW total = W horizontal + W vertical= 0 + 98 = 98J
Correct answer: 98 J- A. 1260 W
- B. 12.6 kW
- C. 210 W
- D. 12.6 W
Explanation: To find : the power of the heater if the specific heat capacity of water is 4.2 J/g/C is..solution : first we should find the energy…
Correct answer: 210 W- A. 3000 N
- B. 30000 N
- C. 300000 N
- D. 300 N
Explanation: To find the pushing force exerted by the motorbike engine, we can use the equation: Power = Force × Velocity (P = W/T = Fd/T = Fv as d/T…
Correct answer: 3000 N- A. 45 Js-1
- B. 35 Js-1
- C. 25 Js-1
- D. 195 Js-1
Explanation: The instantaneous power applied to a particle can be calculated using the formula:Power = Force · VelocityGiven that the velocity of the…
Correct answer: 45 Js-1- A. 1 sec
- B. 4 sec
- C. 8 sec
- D. 10 sec
Explanation: As P=W/t , Therefore,t=W/PUsing valuest= 20/20t= 1 secSo, this option is right.
Correct answer: 1 sec- A. 3 times
- B. 9 times
- C. 27 times
- D. 81 times
Explanation: Option A is correct.We know thatPower is given byP,=mgh/tPis directly proportional to m (For same height and time)P,=3mgh/t=3P (m,=3m)
Correct answer: 3 times- A. 500 J
- B. 5000 J
- C. 3750 J
- D. 475 J
Explanation: Work done against friction = Loss in Kinetic EnergyLoss in Kinetic Energy (ΔKE) = 1/2 x m (u2 - v2)Where 'u' is the initial velocity and…
Correct answer: 3750 J- A. S1=S2
- B. S1<S2
- C. S1>S2
- D. None of these
Explanation: According to Work-Energy PrincipleChange in K.E= W frictionChange in K.E = FdcosStopping distance = dSince both cars have same K.E, so…
Correct answer: S1=S2- A. Total
- B. Potential
- C. Kinetic
- D. All of these
Explanation: Since the type of work that is being done isn't specified, a body can have either kinetic energy due to motion or potential energy due to…
Correct answer: All of these- A. ½mv²=mgh+fh
- B. mgh=½mv²-fh
- C. fh=mgh+½mv²
- D. mgh=½mv²+fh
Explanation: Throughout the course of this fall, we would be having the gravitational potential energy converted to kinetic energy and the energy…
Correct answer: mgh=½mv²+fh- A. at any instant
- B. averagely
- C. during its operation
- D. during one cycle
Explanation: The enclosed area in a PV diagram for a thermodynamic cycle represents the net work done by the system during one cycle.
Correct answer: during one cycle- A. Isothermal expansion
- B. Adiabatic expansion
- C. Isobaric process
- D. Isochoric processIn an isochoric (constant volume) process, no work is done because there is no change in volume. However, the other processes listed involve some work done by the system, but the maximum work is done in an isobaric process, where pressure remains constant.
Explanation: In an isochoric (constant volume) process, no work is done because there is no change in volume.
Correct answer: Isochoric processIn an isochoric (constant volume) process, no work is done because there is no change in volume. However, the other processes listed involve some work done by the system, but the maximum work is done in an isobaric process, where pressure remains constant.- A. Gradient of the tangent of the curve of P-V graph
- B. Gradient of the tangent of the curve of P-T graph
- C. Area of the curve under the P-V graph
- D. Area of the curve under the P-T graph
Explanation: The work done (W) in a thermodynamic process can indeedbe calculated by finding the area under the P-V graph (pressure-Volume…
Correct answer: Area of the curve under the P-V graph- A. Adiabatic
- B. Isobaric
- C. Isochoric
- D. Isothermal
Explanation: For given expansion from V₁ to V₂, the work done is the area under the P-V curve.
Correct answer: Isobaric- A. Free expansion
- B. An isothermal expansion
- C. Isobaric
- D. An expansion at constant temperature
Explanation: The formula W = PΔV = P(V₂-V₁) calculates work done under the condition that pressure (P) is constant throughout the process.
Correct answer: Isobaric- A. PΔV
- B. VΔP
- C. nRT ln(V₂/V₁)
- D. Zero
Explanation: In isobaric process, pressure is constant, work done is W = PΔV, where P is constant pressure and ΔV is change in volume.
Correct answer: PΔV- A. Zero
- B. P/V
- C. -P/V
- D. V/P
Explanation: For isothermal process, PV = constant. Differentiating, P dV + V dP = 0, so dP/dV = -P/V, which is slope of the PV curve.
Correct answer: -P/V- A. During the process AB work done by the gas is positive
- B. During the process AB work done by the gas is negative
- C. During the process BC internal energy of the gas is increasing
- D. None of these
Explanation: We know that,f(density)=nM/V [Mass=moles×Molar mass](Volume)so,V= nM/V (i)In process AB f is constant,Also, V→constant [By eq -…
Correct answer: During the process AB work done by the gas is positive