If the door of a refrigerator is kept open in an insulated room,the temperature of the air in the room will . . . . . .

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:

The temperature of the freezer compartment of an ideal refrigerator is $-13 \, ^\circ C$. If the coefficient of performance of the refrigerator is $5$,then the temperature of the surroundings (to which heat is rejected) is:

$A$ household refrigerator with a coefficient of performance $1.2$ removes heat from the refrigerated space at the rate of $60 \ kJ/min$. What would be the cost of running this fridge for one month $(30 \ days)$, assuming it is used for $4 \ hours$ each day and the cost of one electrical unit is $6 \ Rs.$?

Draw a schematic representation of a refrigerator.

$A$ Carnot engine,having an efficiency of $\eta = 1/10$ as a heat engine,is used as a refrigerator. If the work done on the system is $10 \ J$,the amount of energy absorbed from the reservoir at a lower temperature is ....... $J$.