301. An isolated system can exchange __________ with its surroundings.
A. Matter
B. Energy
C. Neither matter nor energy
D. Both matter and energy
✅ The correct answer is option C.
Thermodynamics MCQs
302. The specific heat of saturated water vapour at 100°C is
A. ∞
B. -ve
C. 0
D. +ve
✅ The correct answer is option B.
303. The efficiency of a Carnot heat engine operating between absolute temperatures T₁ and T₂ (when, T₁ > T₂) is given by (T₁ – T₂)/T₁. The co-efficient of performance (C.O.P.) of a Carnot heat pump operating between T₁ and T₂ is given by
A. T₁/(T₁-T₂)
B. T₂/(T₁-T₂)
C. T₁/T₂
D. T₂/R1
✅ The correct answer is option A.
304. Entropy change in case of reversible adiabatic process is
A. Minimum
B. Zero
C. Maximum
D. Indeterminate
✅ The correct answer is option B.
305. In an irreversible process
A. Tds = dE – dW = 0
B. DE – dW – Tds = 0
C. Tds – dE + dW< 0
D. Tds – dT + dW< 0
✅ The correct answer is option C.
306. With increase in temperature, the atomic heat capacities of all solid elements
A. Increases
B. Decreases
C. Remains unchanged
D. Decreases linearly
✅ The correct answer is option A.
307. 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.
308. 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.
309. 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.
310. 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.