71. Which of the following is not correct for a reversible adiabatic process?
A. TVγ-1 = constant
B. P1-γ.TY = constant
C. PVγ = constant
D. None of these
✅ The correct answer is option D.
Thermodynamics MCQs
72. Which of the following is not an extensive property?
A. Free energy
B. Entropy
C. Refractive index
D. None of these
✅ The correct answer is option C.
73. The activity of an ideal gas is numerically __________ its pressure.
A. More than
B. Less than
C. Equal to
D. Data insufficient, can’t be predicted
✅ The correct answer is option C.
74. All gases except __________ shows a cooling effect during throttling process at atmospheric temperature and pressure.
A. Oxygen
B. Nitrogen
C. Air
D. Hydrogen
✅ The correct answer is option D.
75. In an isothermal process on an ideal gas, the pressure increases by 0.5 percent. The volume decreases by about __________ percent.
A. 0.25
B. 0.5
C. 0.75
D. 1
✅ The correct answer is option B.
76. Chemical potential (an intensive property) of a substance is a force that drives the chemical system to equilibrium and is equal to its partial molar properties. The reatio of chemical potential to free energy of a pure substance at oconstant temperature and pressure is
A. 0
B. 1
C. ∞
D. None of these
✅ The correct answer is option B.
77. Which of the following liquid metals has the highest thermal conductivity?
A. Molten sodium
B. Molten lead
C. Mercury
D. Molten potassium
✅ The correct answer is option A.
78. The value of Cp & Cv respectively for monoatomic gases in Kcal/kg Mole . °K are
A. 5 & 3
B. 3.987 & 1.987
C. 1.987 & 0.66
D. 0.66 & 1.987
✅ The correct answer is option A.
79. In the equation, PVn = Constant, if the value of n = 0, then it represents a reversible __________ process.
A. Isobaric
B. Isothermal
C. Isentropic
D. Isometric
✅ The correct answer is option A.
80. Degree of freedom of the system ice-water-vapour will be
A. 0
B. 1
C. 2
D. 3
✅ The correct answer is option A.