The thermal efficiency of an ideal gas turbine plant is given by (where r = Pressure ratio)
A
$${{\text{r}}^{\gamma - 1}}$$
B
$$1 - {{\text{r}}^{\gamma - 1}}$$
C
$$1 - {\left( {\frac{1}{{\text{r}}}} \right)^{\frac{\gamma }{{\gamma - 1}}}}$$
D
$$1 - {\left( {\frac{1}{{\text{r}}}} \right)^{\frac{{\gamma - 1}}{\gamma }}}$$
Correct Answer: $$1 - {\left( {\frac{1}{{\text{r}}}} \right)^{\frac{{\gamma - 1}}{\gamma }}}$$