The overall thermal efficiency of an ideal gas turbine plant is (where r = Pressure ratio)

The overall thermal efficiency of an ideal gas turbine plant is (where r = Pressure ratio)

(A) r ^ɣ-1

(B) 1 – r ^ɣ-1

(C) 1 – (1/r) ^ɣ-1/ɣ         (Ans)

• (D) 1 – (1/r) ɣ/ɣ-1