A. More
B. Less
C. Same
D. More or less ; depending on the system
✅ The correct answer is option C.
Thermodynamics MCQs
High __________ is an undesirable property for a good refrigerant.
A. Specific heat
B. Latent heat of vaporisation
C. Viscosity
D. Specific vapor volume
✅ The correct answer is option C.
For spontaneous changes in an isolated system (S = entropy)
A. Ds = 0
B. Ds <0
C. Ds > 0
D. Ds = Constant
✅ The correct answer is option C.
For a stable phase at constant pressure and temperature, the fugacity of each component in a binary system __________ as its mole fraction increases.
A. Decreases
B. Increases
C. Remains same
D. Decreases linearly
✅ The correct answer is option B.
As the time is passing, entropy of the universe
A. Is increasing
B. Is decreasing
C. Remains constant
D. Data insufficient, can’t be predicted
✅ The correct answer is option A.
In a P-V diagram (for an ideal gas), an isothermal curve will coincide withan adiabatic curve (through a point), when
A. Cp < Cv
B. Cp = Cv
C. Cp > Cv
D. Cp ≥ Cv
✅ The correct answer is option B.
The first law of thermodynamics is a statement of conservation of
A. Heat
B. Momentum
C. Energy
D. Work
✅ The correct answer is option C.
Gibbs free energy at constant pressure and temperature under equilibrium conditions is
A. ∞
B. 0
C. Maximum
D. Minimum
✅ The correct answer is option D.
Any substance above its critical temperature exists as
A. Saturated vapour
B. Solid
C. Gas
D. Liquid
✅ The correct answer is option C.
Helmholtz free energy (A) is defined as
A. A = H – TS
B. A = E – TS
C. A = H + TS
D. None of these
✅ The correct answer is option B.