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 33 of 36
- A. Temperature remains constant
- B. Pressure remains constant
- C. Volume remains constant
- D. There is no transfer of heat
Explanation: In an adiabatic process, there is no transfer of heat between the system and the surroundings i.e.
Correct answer: There is no transfer of heat- A. Hot reservoir is at 0K
- B. Hot reservoir is at 0C
- C. Cold reservoir is at 0C
- D. Cold reservoir is at 0 Kelvin
Explanation: Cold reservoir at 0K: This is the only option that could theoretically allow for an ideal reversible heat engine to be 100% efficient.
Correct answer: Cold reservoir is at 0 Kelvin- A. 70J
- B. 150J
- C. 190J
- D. 180J
Explanation: Since heat is being added, so work is being done by system. ΔU = Heat supplied - Work done by the system= 110 - 40 = 70J
Correct answer: 70J- A. No heat is added to or taken out of a system
- B. No change of temperature takes place
- C. Boyle's law is applicable
- D. Pressure and volume remains constant
Explanation: In an adiabatic process, no energy is added to or removed from the system in the form of heat.
Correct answer: No heat is added to or taken out of a system- A. A
- B. B
- C. C
- D. D
Explanation: The average translational energy of a molecule is given by the equipartition theorem as, E=3kT2 where k is the Boltzmann constant and T is…
Correct answer: A- A. Cp < Cv
- B. Cp = Cv
- C. Cp > Cv
- D. Cp = Constant
Explanation: So, Cp is greater than Cv, and Cp - Cv = R is a representation of this relationship for ideal gases.
Correct answer: Cp > Cv- A. 1.5
- B. 44319
- C. 44257
- D. 44289
Explanation: Answer: 1.5Given that, p∝T³ or pT^-3 = constant .....(i) Also for adiabatic process pV^Γ = constant but pV=RT (ideal gas law) or V= RT/p…
Correct answer: 1.5- A. 32°C
- B. 100°C
- C. 273°C
- D. 0°C
Explanation: The Celsius scale has an upper fixed point and a lower fixed point. The upper fixed point is 100°C and the lower fixed point is 0°C.
Correct answer: 0°C- A. The temperature of the sink is 0°C.
- B. The temperature of the sink is 0 K.
- C. The temperature of the source is 0.
- D. The temperature of the sink is equal to the temperature of the source.
Explanation: Heat engines can't achieve 100% thermal efficiency according to the Second law of thermodynamics.
Correct answer: The temperature of the sink is 0 K.- A. Red
- B. Green
- C. Blue
- D. White
Explanation: Its color depends only on its temperature. By definition, a black body does not reflect light, and only emits light by radiation because…
Correct answer: White- A. Rmc
- B. R/me
- C. me/R
- D. Rm/c
Explanation: We know that Q = mcΔTDividing both sides of the equation by time gives:Q/t = mcΔT/tQ/t = rate of heat transferΔT/t = RTherefore: rate of…
Correct answer: Rmc- A. Bad conductivity
- B. Good conductivity
- C. Low temperature
- D. None of these options are correct
Explanation: Since air is a bad conductor of heat, it prevents the loss of heat from the body, thus keeping it warm.
Correct answer: Bad conductivity653. If the engine is supposed to work between 727°C and 227°C, then the maximum possible efficiency is:
- A. 1/2
- B. 1/4
- C. 3/4
- D. 1
Explanation: T1 = 727 + 273 = 1000 K T2 = 227 + 273 = 500 K Efficiency of engine = 1 - (T2/T1) = 1 - (500/1000) = 1 - ½ = ½ Hence, option A is the…
Correct answer: 1/2- A. 4 g
- B. 40 g
- C. 240 g
- D. 24 g
Explanation: An explanation for this question is given below: We know that P = 100W, t = 5 x 60 = 300s, T = 30 C, and c = 4.2 We will use the formula Q…
Correct answer: 240 g- A. Absorbs
- B. Releases
- C. First absorbs than releases
- D. First releases than absorbs
Explanation: The process of evaporation followed by condensation result in cloud formation.
Correct answer: First absorbs than releases- A. Internal energy
- B. Temperature of a body
- C. Kinetic energy
- D. Heat energy
Explanation: Correct option is D. Heat energy is another name for thermal energy. Its sources are the same as that of heat energy.
Correct answer: Heat energy- A. 700C
- B. 600C
- C. 500C
- D. 400C
Explanation: Since the container has negligible thermal capacity, the heat lost by the hot water (80°C) will be equal to the heat gained by the cold…
Correct answer: 500C- A. 4.98J
- B. 7.98J
- C. 4.l8J
- D. 8.21J
Explanation: One kilocalorie is equal to 4.184 joules so one calorie would be equal to "4.18" joules hence the answer C.
Correct answer: 4.l8J- A. Slow compression of a gas into a cylinder
- B. Changes due to friction
- C. Explosion
- D. Dissipation of energy
Explanation: The correct answer is Option A: Slow compression of a gas into a cylinder.
Correct answer: Slow compression of a gas into a cylinder- A. Option A
- B. Option B
- C. Option C
- D. Option D
Explanation: In the context of thermodynamics and gas behavior, an "isotherm" refers to a curve or line on a graph representing a process that occurs…
Correct answer: Option D