If a refrigerator of coefficient of performance of $5$ has a freezer at a temperature of $-13^{\circ} C$,then the room temperature is (in $^{\circ} C$)

$A$ refrigerator works between $4^{\circ}C$ and $30^{\circ}C$. It is required to remove $600 \, cal$ of heat every second in order to keep the temperature of the refrigerated space constant. The power required is ....... $W$ (Take $1 \, cal = 4.2 \, J$)

The coefficient of performance of a Carnot refrigerator working between temperatures $30 \, ^\circ\text{C}$ and $0 \, ^\circ\text{C}$ is:

If the sink and source temperatures of a refrigerator are $4^{\circ} C$ and $15^{\circ} C$ respectively,then the efficiency of the refrigerator is:

In a refrigerator,one removes heat from a lower temperature and deposits it to the surroundings at a higher temperature. In this process,mechanical work has to be done,which is provided by an electric motor. If the motor is of $1\,kW$ power and heat is transferred from $-3\,^{\circ}C$ to $27\,^{\circ}C$,find the heat taken out of the refrigerator per second,assuming its efficiency is $50\%$ of a perfect engine.

$A$ refrigerator is to maintain eatables kept inside at $9^{\circ} C$. If room temperature is $36^{\circ} C$,calculate the coefficient of performance.