T1=T2=500°C
Explanation:
Given-
Pressure, P1 = 500 bar
Temperature, T1 = 500°C
P2 = 1 bar
T2 after expansion, = ?
We know,
P1/T1 = P2/T2
500/ 500 = 1/T2
T2 = 1°C
If the steam were replaced by an ideal gas, since enthalpy of ideal gas is a function of temperature only, we easily obtain T2 = T1 = 500°C