A refrigerator has to transfer an average of $263J$ of heat per second from temperature $-10°C$ to $25°C$. Calculate the average power consumed, assuming no energy losses in the process.

Here, $T_1=25+273=298K$

$T_2=-10+273=263K$

$Q_2=263J/s$

Coefficient of performance is given by

$\beta =\frac{Q_2}{Q_1-Q_2}=\frac{T_2}{T_1-T_2}$

$\therefore \frac{Q_1}{Q_2}=\frac{T_1}{T_2}$

$\therefore Q_1=\frac{T_1}{T_2}\times Q_2=\frac{298}{263}\times 263$

$=298J{s}^{-1}$

Average power consumed,

$=298-263=35J{s}^{-1}=35W$