Work & Heat Transfer in Engineering Thermodynamics by PK NAG (Chapter 03)

A: The correct answer lands in the few hundred kJ/kg range, consistent with ideal-gas polytropic work using R·T and a moderate pressure ratio. Option B collapses the magnitude by confusing isothermal limits with actual polytropic behaviour. Option C over-scales linearly with pressure ratio and ignores the logarithmic/exponent relationship. Option D mixes up closed-system work with internal energy accounting.

A: The correct answer identifies shaft work as the source term that converts to internal energy when heat loss is constrained. Option B ignores insulation and assumes an external reservoir. Option C misreads the first law as enforcing equality rather than balance. Option D imports an incompressibility assumption that doesn't nullify viscous dissipation.

A: The correct answer reflects that small volume change in liquids collapses boundary work to a rounding error. Option B invents a restriction that doesn't exist in testing practice. Option C assumes ideal equipment rather than physical properties. Option D confuses accounting convenience with physical behaviour.

A: The correct answer captures direct conversion of shaft work into internal energy under adiabatic conditions. Option B confuses geometric constraint with energy balance. Option C invents a pressure response not dictated by the first law. Option D drags in second-law data that isn't required here.