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

Obtain the formula for the coefficient of performance of a Carnot refrigerator.

The temperature inside a refrigerator is $t_2 \, ^\circ C$ and the room temperature is $t_1 \, ^\circ C$. The amount of heat delivered to the room for each joule of electrical energy consumed ideally will be:

If the door of a refrigerator is kept open,then which of the following is true?

Explain the working of refrigerators/heat pumps and their coefficient of performance.

$A$ Carnot freezer takes heat from water at $0\,^{\circ}C$ inside it and rejects it to the room at a temperature of $27\,^{\circ}C$. The latent heat of ice is $336 \times 10^3\, J\,kg^{-1}$. If $5\, kg$ of water at $0\,^{\circ}C$ is converted into ice at $0\,^{\circ}C$ by the freezer,then the energy consumed by the freezer is close to