$A$ Carnot heat engine has an efficiency of $10 \%$. If the same engine is worked backward to obtain a refrigerator,then the coefficient of performance of the refrigerator is

Freezing compartment of a refrigerator is at $0^{\circ} C$ and room temperature is $27.3^{\circ} C$. Work done by the refrigerator to freeze $1 \ g$ of water at $0^{\circ} C$ is $(L_{\text{ice}} = 80 \ cal \ g^{-1})$. (in $J$)

The door of a working refrigerator is left open in a well-insulated room. The temperature of the air in the room will

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.

The power of a refrigerator that can make $15 \ kg$ of ice at $0^{\circ}C$ from water at $30^{\circ}C$ in one hour is: (in $W$)

Assertion $(A)$: $A$ room can be cooled by opening the door of a refrigerator in it.
Reason $(R)$: Heat always flows from a body at higher temperature to a body at lower temperature.