75. Steam expands adiabatically in a turbine from 2000 kPa, 400°C to 400 kPa, 250°C. What is

the effectiveness of the process in percent assuming an atmospheric pressure of 18°C? Neglect

changes in kinetic and potential energy.

Steam properties:

@ 2000 kPa and 400°C: h = 3247.6 kJ/kg s = 7.1271kJ/kg-K

@ 400 kPa and 250°C: h = 2964.2 kJ/kg s = 7.3789 kJ/kg-K

A. 82 B. 84 C. 79.60 D. 79.46