Answer:
15.65 °C
Step-by-step explanation:
cold temperature (Tc) = -15.5 degree C = 273.15 - 15.5 = 257.65 kelvin
minimum coefficient of performance (η) = 8.25
find the maximum hot reservoir temperature of such a generator (Th)
η = \frac{Tc}{Th-Tc}
Th = Tc x (\frac{1}{η} + 1)
Th = 257.65 x (\frac{1}{8.25} + 1)
Th = 288.8 K
Th = 288.8 - 273.15 = 15.65 °C