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 14 of 36
- A. Isochoric process
- B. Isobaric process
- C. Adiabatic process
- D. Isothermal process
Explanation: The correct answer is the isothermal process. In this process, the temperature of the system remains constant, which means there is no…
Correct answer: Isothermal process- A. Working of bicycle pump
- B. Brakes applied by an automobile
- C. Human metabolism
- D. All of the above
Explanation: Human metabolism, brakes applied by an automobile and working of bicycle pump are all examples of first law of thermodynamics.
Correct answer: All of the above- A. A
- B. B
- C. C
- D. D
Explanation: As the gas expands, W is negative, also ∆U decreases and gas expand. There is no heat supplied to the system.
Correct answer: B- A. -600J
- B. 0J
- C. 200J
- D. -200J
Explanation: W = ∆P∆V = 1x105x2x10-3 = 2x102 = 200J W=positive because work done by yz path is more than xw path
Correct answer: 200J- A. To do external work
- B. Internal energy of the gas increases
- C. Both 'A' and 'B'
- D. None of these
Explanation: lsochoric process. When heat is added at constant volume (an isochoric process), it primarily increases the internal energy of the system…
Correct answer: Internal energy of the gas increases- A. Then the work is done by the gas
- B. Internal energy of the gas increases
- C. Both A and B
- D. None of these
Explanation: Properties of isobaric process. When heat is added to a gas in an isobaric process, a part of it is used to do external work while the…
Correct answer: Both A and B- A. Positive in all cases (i) to (iv)
- B. Negative in cases (i), (ii) and (iii) but zero in (iv) case
- C. Positive in cases (i), (ii) and (iii) but zero in (iv) case
- D. Zero in all four cases
Explanation: In case of any cyclic process change in internal energy is zero. Here, the given four diagrams are representing the cyclic process.
Correct answer: Zero in all four cases- A. Totally K.E
- B. Partly K.E and partly P.E
- C. Totally P.E
- D. Neither K.E nor P.E
Explanation: The internal energy changes in an ideal gas can be described solely by change in its kinetic energy.
Correct answer: Totally K.E- A. A
- B. B
- C. C
- D. D
Explanation: For an isothermal process, the heat added to an ideal system versus work performed by that system is represented graphically as a straight…
Correct answer: B- A. γ= Cp/Cv
- B. Cp+Cv=γ
- C. Cp=1+R/Cv
- D. Cp=1-R/Cv
Explanation: Boyle's Law describes the inverse relationship between the pressure and volume of a gas at constant temperature.
Correct answer: γ= Cp/Cv- A. heat capacities
- B. volume
- C. thermal conductivities
- D. co efficient of expensation
Explanation: Heat capacity is the measure of how much heat energy is required to raise the temperature of a substance by a certain amount.
Correct answer: heat capacities- A. Cp = Cv
- B. Cv > Cp
- C. Cv < Cp
- D. Cv ≥ Cp
Explanation: For an ideal gas, during an isochoric (constant volume) process, the specific heat at constant volume (Cv ) is equal to the specific heat…
Correct answer: Cp = Cv- A. Translational
- B. Vibrational
- C. Rotational
- D. All
Explanation: Diatomic molecules possess translational kinetic energy (related to their overall motion), vibrational kinetic energy (due to the…
Correct answer: All- A. R/ NA
- B. NA/R
- C. 1/ R×NA
- D. R×NA
Explanation: Boltzmann's constant (k) is defined as the universal gas constant (R) divided by Avogadro's number (NA ). It is denoted as k= R/ NA .
Correct answer: 1/ R×NA- A. Double
- B. Four times
- C. Half
- D. Remains the same
Explanation: According to the kinetic theory of gases, pressure is directly proportional to the mean square velocity of gas molecules.
Correct answer: Four times- A. Copper
- B. Aluminum
- C. Iron
- D. Ice
Explanation: The specific heat is the amount of heat energy required to raise the temperature of a unit mass of a substance by one degree Celsius.
Correct answer: Ice- A. 4.51 J/g
- B. 4.18 J/g
- C. 4.92 J/g
- D. 4.21 J/g
Explanation: The heat capacity of water is approximately 4.18 joules per gram per degree Celsius (J/g°C).
Correct answer: 4.18 J/g- A. 2/5R
- B. 2/7R
- C. 5/2R
- D. 7/2R
Explanation: For an ideal gas, the relationship between molar specific heats is given by Mayer's formula: Cp - Cv = R.
Correct answer: 7/2R- A. Cp + Cv = R
- B. Cp - R = Cv
- C. Cv - R = Cp
- D. Cp + R = Cv
Explanation: Mayer's formula describes the relationship between the molar specific heats for an ideal gas, which is Cp - Cv = R.
Correct answer: Cp - R = Cv- A. 24.9 J/mol·K
- B. 12.9 J/mol·K
- C. 15 J/mol·K
- D. 16 J/mol·K
Explanation: For a non-linear polyatomic gas, there are 3 translational and 3 rotational degrees of freedom (f=6).
Correct answer: 24.9 J/mol·K