Question

The coefficient of performance of a refrigerator is 5 .If the temperarture inside freezer is - 20${}^0$C, the temperature of the surroundings to which it rejects heat is

Answer 1

$5=\frac{heat}{workdone}$

$5=\frac{T\left(fr\right)}{T\left(surr\right)-T\left(fr\right)}$

$5=\frac{253K}{T-253}$

$5T-1265=253$

$5T=1518$

$T=303.6Kor{30.6}^{0}C$

We get, $T={30.6}^{0}C.$