![A gas turbine with air as the working fluid has an isentropic efficiency of 0.70 when operating at a pressure ratio of 3](https://www.gkseries.com/blog/wp-content/uploads/2023/09/A-gas-turbine-with-air-as-the-working-fluid-has-an-isentropic-efficiency-of-0.70-when-operating-at-a-pressure-ratio-of-3.jpg)
Q. A gas turbine with air as the working fluid has an isentropic efficiency of 0.70 when operating at a pressure ratio of 3. Now, the pressure ratio of the turbine is increased to 5, while maintaining the same inlet conditions. Assume air as a perfect gas with specific heat ratio g = 1.4 . If the specific work output remains the same for both the cases, the isentropic efficiency of the turbine at the pressure ratio of 5 is (round off to two decimal places)
Ans: 0.514
Sol:
![](https://www.gkseries.com/blog/wp-content/uploads/2023/09/Screenshot-685.png)
Consider it is asked only for turbine portion as for full cycle,data is not sufficient