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 15 of 36
- A. Diatomic
- B. Mixture of diatomic and polyatomic
- C. Monoatomic
- D. Polyatomic
Explanation: Ratio R/Cv is related to degrees of freedom (f) by Cv = (f/2)R, so R/Cv = 2/f.
Correct answer: Monoatomic- A. ∞
- B. Zero
- C. Finite but not zero
- D. 0 < C < ∞
Explanation: This question is conceptually tricky. Specific heat is a property of a substance, but in an adiabatic process, heat transfer Q is zero by…
Correct answer: Zero- A. Entropy
- B. General gas constant
- C. Internal energy
- D. Pressure
Explanation: Unit for molar specific heat (C) is J/mol·K. The unit for the general gas constant (R) is also J/mol·K, as seen in the ideal gas law.
Correct answer: General gas constant- A. 5R/2
- B. 3R/2
- C. 7R/2
- D. R
Explanation: For a diatomic gas, Cv = 5R/2. Using the relation Cp = Cv + R, we get Cp = (5R/2) + R = 7R/2, where R is the gas constant.
Correct answer: 7R/2- A. Zero
- B. Infinite
- C. Cᵥ
- D. Cₚ
Explanation: In an isobaric process, pressure is constant, and the specific heat capacity used is Cp (specific heat at constant pressure), which…
Correct answer: Cₚ- A. R
- B. 3R/2
- C. 5R/2
- D. 7R/2
Explanation: For a monoatomic gas, with three translational degrees of freedom, the molar specific heat at constant volume is Cv = (3/2)R, where R is…
Correct answer: 3R/2- A. Its mass only
- B. Its temperature only
- C. Its material properties
- D. Its volume only
Explanation: Specific heat capacity is an intrinsic property of a material, varying based on its chemical composition and structure, not on mass…
Correct answer: Its material properties- A. nCvΔT
- B. nCpΔT
- C. PΔV
- D. Zero
Explanation: Internal energy change for an ideal gas depends only on temperature, ΔU = nCvΔT, regardless of the process.
Correct answer: nCvΔT- A. Cp = Cv
- B. Cp = Cv + R
- C. Cp = Cv - R
- D. Cp = 2Cv.
Explanation: For an ideal gas, molar specific heat at constant pressure is related to that at constant volume by Cp = Cv + R, where R is the gas…
Correct answer: Cp = Cv + R- A. Carnot engine
- B. Molar specific heat
- C. Kinetic specific heat
- D. General gas law
- E. Boyle's law
Explanation: Specific heat is the amount of heat needed to raise the temperature of one kilogram of mass by 1 degree.
Correct answer: Molar specific heat291. "The heat required to raise the temperature of one mole of the substance through 1 K" is called:
- A. Specific latent heat
- B. Heat capacity
- C. Molar specific heat
- D. Specific heat capacity
Explanation: Molar specific heat capacity is the heat energy required to raise the temperature of 1 mole of a substance by.
Correct answer: Molar specific heat- A. H2
- B. He
- C. CH2
- D. Mixture of H2 and He
Explanation: The correct answer is hydrogen gas (H2) because it is a diatomic molecule that adheres to the equation P^y = T^z, where y = 4 and z = 1…
Correct answer: H2- A. 3 / 2
- B. 1 / 2
- C. 4 / 2
- D. None
Explanation: The molar specific heat capacity of a gas at constant volume (Cv) is the amount of heat required to raise the temperature of 1 mole of the…
Correct answer: 3 / 2- A. Cp = Cv
- B. None of these
- C. Cp > Cv
- D. Cv > Cp
Explanation: CV is the specific heat at constant volume, and CP is the specific heat at constant pressure.When a gas is heated at a constant volume…
Correct answer: Cp > Cv- A. 0.8
- B. 1.29
- C. 1.42
- D. 1.66
Explanation: The ratio of the specific heats γ=CP/CV is a factor in adiabatic engine processes and in determining the speed of sound in a gas.This…
Correct answer: 1.29- A. PV=nRT
- B. Cp-Cv=R
- C. Cp/Cv=R
- D. W= F.d
Explanation: All of the other options have formulae that are correct. Cp-Cv=R indicates the relationship of specific heat constants with a gas.
Correct answer: Cp/Cv=R- A. 3/2R
- B. 2R
- C. 2/3R
- D. 3R
Explanation: The amount of energy required to raise the temperature of gas through 1°C /1 K at constant pressure is greater than the amount of energy…
Correct answer: 3R- A. ΔU + Cv = ΔT
- B. ΔU = Cv-ΔT
- C. ΔU = CvΔT
- D. ΔU=Cv+ΔT
Explanation: Isochoric Process:The thermodynamics process during which the volume of the system remains constant is called isochoric process.As the…
Correct answer: ΔU = CvΔT- A. More for (i)
- B. More for (ii)
- C. Same for both
- D. Independent of the number of moles
Explanation: Change in internal energy will be ΔU = nCvΔT for both process (at constant volume and constant pressure).
Correct answer: Same for both- A. 935J
- B. 934J
- C. 967J
- D. 954J
Explanation: Given: Mass = m = 0.02 kg Temperature = ∆T = 45°CSolution: n = m/M = 20/28 = 0.714 mol Cp = 7/2 R = 7/2 × 8.3 = 29.05 J/mol.KAs we know…
Correct answer: 934J