Determine the coefficient of performance for the given temperature limits.
$T_{1} = 27^{\circ}C$ [outside fridge]
$T_{2} = -23^{\circ}C$ [inside fridge]

$A$ refrigerator with a coefficient of performance of $1/3$ releases $200 \ J$ of heat. What is the work done on the working substance in Joules?

$A$ Carnot's engine works as a refrigerator between $250\, K$ and $300\, K$. It receives $500\, cal$ heat from the reservoir at the lower temperature. The amount of work done in each cycle to operate the refrigerator is ..... $J$

If minimum possible work is done by a refrigerator in converting $100 \; g$ of water at $0^{\circ} C$ to ice,how much heat (in calories) is released to the surrounding at temperature $27^{\circ} C$ (Latent heat of ice $= 80 \; cal/g$)? Round to the nearest integer.

An ideal refrigerator has a freezer at a temperature of $-13^{\circ} C$. The coefficient of performance of the refrigerator is $5$. The temperature of the air (to which heat is rejected) is:

Why can the coefficient of performance of a refrigerator never be infinite?