Question

A refrigerator uses 40.0 J of work to extract heat from a heat reservoir at 0.00°C. If the coefficient of performance of the refrigerator is 2.10, then how much heat is discharged out of the refrigerator at a higher temperature?

Answer 1

Heat discharged out of the refrigerator = 84 J

Explanation:

Coefficient of performance:

Ratio of work output to the amount of work or energy input. Coefficient of performance used generally as a measure of the energy ratio of air conditioners, space heaters. etc

Generally, Coefficient of performance (COP) = Wok output/ work input

Work output = Heat discharged out of the refrigerator, Work input = Electrical energy used by the refrigerator.

∴ Coefficient of performance (COP) = Heat discharged out of the refrigerator/ Electrical energy used by the refrigerator.

The energy used by the refrigerator = 40.0 J and

Coefficient of performance (COP) =2.10.

Heat discharged out of the refrigerator = 40 × 2.10 = 84 J

∴ Heat discharged out of the refrigerator = 84 J