A. Increases
B. Decreases
C. Remains unchanged
D. Decreases linearly
✅ The correct answer is option A.
Thermodynamics MCQs
An irreversible process
A. Is the analog of linear frictionless motion in machines
B. Is an idealised visualisation of behaviour of a system
C. Yields the maximum amount of work
D. Yields an amount of work less than that of a reversible process
✅ The correct answer is option D.
Gibbs-Duhem equation
A. States that n₁dμ₁ + n₂dμ₂ + ….njdμj = 0, for a system of definite composition at constant temperature and pressure
B. Applies only to binary systems
C. Finds no application in gas-liquid equilibria involved in distillation
D. None of these
✅ The correct answer is option A.
Gibbs free energy (F) is defined as
A. F = E – TS
B. F = H – TS
C. F = H + TS
D. F = E + TS
✅ The correct answer is option B.
The efficiency of an Otto engine compared to that of a diesel engine, for the same compression ratio will be
A. More
B. Less
C. Same
D. Data insufficient to predict
✅ The correct answer is option A.
Boyle’s law for gases states that
A. P ∝ 1/V, when temperature is constant
B. P ∝ 1/V, when temperature & mass of the gas remain constant
C. P ∝ V, at constant temperature & mass of the gas
D. P/V = constant, for any gas
✅ The correct answer is option B.
The internal energy of an incompressible fluid depends upon its
A. Pressure
B. Temperature
C. Both A & B
D. Neither A nor B
✅ The correct answer is option B.
Entropy of an ideal gas depends upon its
A. Pressure
B. Temperature
C. Both A & B
D. Neither A nor B
✅ The correct answer is option C.
Pressure-enthalpy chart is useful in refrigeration. The change in internal energy of an ideal fluid used in ideal refrigeration cycle is
A. Positive
B. Negative
C. Zero
D. Infinity
✅ The correct answer is option C.
The principle applied in liquefaction of gases is
A. Adiabatic expansion
B. Joule-Thomson effect
C. Both A and B
D. Neither A nor B
✅ The correct answer is option C.