Question

A refrigerator placed in a room at 300 k has inside temperature 200k.How many calories of heat shall be delivered to the room for each 2 kilocal of energy consumed by the refrigerator ideally

Answer 1

first of all, we have to find cop e.g., coefficient of performance.

we know, $cop=\frac{T_2}{T_1-T_2}$
where $T_1$ is the temperature in refrigerator and $T_2$ is the temperature of room.

so, cop = 200/(300 - 200) = 2

now, cop = Q2/W
here W = 2Kcal
2 = Q2/2kcal
Q2 =4kcal

now, heat delivered to the room , Q1 = Q2 + W
= 4kcal + 2kcal = 6kcal