(A) isothermal h.p. to the BHP of motor ()
(B) isothermal h.p. to adiabatic h.p. (X)
(C) power to drive compressor to isothermal h.p. (X)
(D) work to compress air isothermally to work for actual compression (X)
(E) isothermal work to ideal work (X)
Answers: The overall isothermal eiffciency of compressor is defined as the ratio of isothermal h.p. to the BHP of motor.