Free Thermodynamics MCQs with Answers
714 Thermodynamics MCQs from Physics, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Thermal equilibrium and heat explain how temperature and energy transfer are related, while molar specific heats describe the heat required by a gas at constant volume or constant pressure. The first law connects heat supplied, work done and change in internal energy, with sign conventions kept distinct from temperature changes.
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Read the Thermodynamics notesFree MDCAT chapter notes with key terms714 questions · page 4 of 36
- A. solid
- B. liquid
- C. both
- D. none
Explanation: Linear expansion is the change in length caused by heating and is normally defined for solids, which have a definite shape and length.
Correct answer: solid- A. K
- B. K-1
- C. K -2
- D. none
Explanation: The coefficient of linear expansion is α = change in length/(original length x change in temperature), so its unit is 1/K, written K^-1.
Correct answer: K-1- A. c-32/9
- B. f -32/9 =c/5
- C. f-32/9=c/9
- D. none
Explanation: The temperature scales are related by (F - 32)/9 = C/5, because 32°F corresponds to 0°C and the intervals 180°F and 100°C give the ratio…
Correct answer: f -32/9 =c/5- A. Specific heat of Vaporization
- B. Specific heat capacity
- C. Caloric heat
- D. Both Options A and B are correct
Explanation: Specific heat capacity is the quantity of heat needed to raise the temperature per unit mass (the amount of heat needed to raise the…
Correct answer: Specific heat capacity- A. 8g, 100 degree centigrade
- B. 100g ,90 degree centigrade
- C. 92g, 100 degree centigrade
- D. 82g, 100 degree centigrade
Explanation: Given, heat supplied = 22320 calmass of ice = 100glatent heat of fusion of ice = 80 cal/glatent heat of vaporization of water = 540…
Correct answer: 92g, 100 degree centigrade- A. reversible isothermal processes
- B. reversible adiabatic processes
- C. reversible processes during which no work is done
- D. reversible isobaric processes
Explanation: During a reversible isothermal process, where the temperature remains constant, and the process is carried out reversibly, the change in…
Correct answer: reversible isothermal processes- A. rapid escape of air from a burst tyre
- B. rapid expansion of air
- C. cloud formation in the atmosphere
- D. conversion of water into ice in refrigerator
Explanation: When water turns into ice in a refrigerator, heat is typically removed from the water to lower its temperature.
Correct answer: conversion of water into ice in refrigerator- A. 40K, 20K
- B. 100K, 80K
- C. 20K, 30K
- D. 60K,40K
Explanation: The efficiency of a Carnot engine is determined by the temperature difference between the hot and cold reservoirs.
Correct answer: 40K, 20K- A. 10%
- B. 20%
- C. 25%
- D. 44%
Explanation: The efficiency of a Carnot engine is determined by the temperature difference between the hot and cold reservoirs.
Correct answer: 20%- A. work
- B. energy
- C. heat
- D. All of these
Explanation: The first law of thermodynamics is a consequence of the conservation of energy, which states that energy cannot be created or destroyed…
Correct answer: All of these- A. Increases
- B. Decreases
- C. Remains the same
- D. Cannot be predicted
Explanation: At constant pressure (isobaric process), the graph between volume (V) and temperature (T) is typically a straight line.
Correct answer: Remains the same- A. Mass
- B. Heat
- C. Energy
- D. All
Explanation: The first law of thermodynamics states that energy cannot be created or destroyed in an isolated system. It can only change forms.
Correct answer: Energy- A. Isobaric
- B. Adiabatic
- C. Isothermal
- D. Isochoric
Explanation: An adiabatic process is one in which no heat enters or leaves the system.
Correct answer: Adiabatic- A. Increases
- B. Decreases
- C. Zero
- D. Remains constant
Explanation: In the Carnot cycle, the internal energy of the working substance remains constant throughout the cycle.
Correct answer: Remains constant- A. W=−Δ(U)
- B. Entropy of system remains the same
- C. Δ(Q)=0
- D. All of these
Explanation: In an adiabatic process, no heat exchange (Δ(Q)=0) occurs between the system and its surroundings (Q=0).
Correct answer: All of these- A. Decreases
- B. Increases
- C. Remains the same
- D. 0
Explanation: During adiabatic expansion, the system performs work on its surroundings without exchanging heat.
Correct answer: Decreases- A. Temperature
- B. Internal energy
- C. Heat
- D. Pressure
Explanation: Heat (Q) is not a state function. It depends on the path taken during a process, whereas state functions like temperature, internal…
Correct answer: Heat- A. P(V2 −V1 )
- B. P(V1 −V2 )
- C. P(V1^γ −V2^γ )
- D. P(1/V1 −1/V2 )
Explanation: The work done by a gas under constant pressure P) during expansion or compression is given by P×(change in volume).
Correct answer: P(V2 −V1 )- A. Volume
- B. Temperature
- C. Pressure
- D. Path followed
Explanation: According to the ideal gas law, the internal energy of an ideal gas depends only on its temperature.
Correct answer: Temperature- A. 100 J
- B. -100 J
- C. 200 J
- D. 1/100 J
Explanation: For an adiabatic process, the change in internal energy (ΔU) is related to the work done (W) by the equation ΔU=−W.
Correct answer: -100 J