Question

A house requires 60 Mcal/hr in winter for heating. Heat pump absorbs heat from cold air outside and requires 8 Mcal/hr of work. The COP will be
1. 0.75
2. 7.5
3. 6.5
4. 10

Answer 1

Correct Answer - Option 2 : 7.5

Concept:

The Coefficient of performance for any device calculated by,

\(COP = \frac{{Desired\;effect}}{{work\;input}}\;\;\; \)

Calculation:

Given:

Here the desired effect is heating a house in winter with the help of a heat pump.

Desired effect = 60 Mcal/hr, Work input = 8 Mcal/hr 

\(COP = \frac{{Desired\;effect}}{{work\;input}}\;\; =\frac{60}{8}= 7.5\; \)