Thermodynamic Relations In Engineering Thermodynamics by Pk NAG (Chapter 11)

A: A follows dh = Tds + vdp; at constant T, entropy change is small but vdp stays. B imports an isentropic compressor idea. C confuses throttling with upstream state. D exaggerates, ignoring real-gas compressibility.

A: B applies dP/dT = h_fg / [T(vg−vf)] with units intact. A drops a zero converting kJ to J. C inverts the relation. D forgets to divide by temperature.

A: A sits upstream; throttling doesn't stop compression heating. B is the expected effect. C is the defining assumption, not a hazard. D is a consequence, not a protected risk.

A: A uses CvΔT directly. B swaps Cp. C rounds Cv incorrectly. D divides by temperature as if entropy were asked.

A: A matches second-law relation. B confuses steady with reversible. C looks only at one control mass. D assumes ideal reversibility that isn't there.

A: A matches the partial derivatives exactly. B is an isotherm, wrong constraint. C mixes variables, wrong hold. D drops pressure entirely.

A: A is outside equilibrium thermodynamics. B and D are exactly what ΔG addresses. C is the explicit output of the equation.

A: B follows directly from rearranging the relation. A flips the derivative. C assumes ideal gas without stating it. D overcomplicates; Cp isn't required for the sign.

A: A flags a real deviation needing root cause. B violates property relations. C discards the governing equation. D ignores trend risk; that's how fleets get grounded.