Question

Efficiency of a Carnot cycle is 75%. If temperature of the hot reservoir is 727ºC, calculate the temperature of the cold reservoir.

Answer 1

Given : η = 75% = 0.75, T_H = (273 + 727) K = 1000 K

η = \(1−\frac{T_C}{T_H}\) ∴  \frac{T_C}{T_H}= 1− η

T_C = T_H (1 − η ) = 1000(1 - 0.75)

= 250 K = (250 − 273)°C

= −23°C

This is the temperature of the cold reservoir.