The equation $\beta = \frac{Q_2}{Q_1 - Q_2}$ is true or false?

$A$ 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?

Define and write the formula for the coefficient of performance of a refrigerator.

$A$ 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 ..... $J$

Why does the coefficient of performance of a refrigerator become infinity?

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