Heat Pump MCQs : This section focuses on the "Heat Pump" in Refrigeration and Air Conditioning. These Multiple Choice Questions (MCQs) should be practiced to improve the Refrigeration and Air Conditioning skills required for various interviews (campus interview, walk-in interview, company interview), placement, entrance exam and other competitive examinations.
A heat pump is basically a heat engine run in the _______________.
A. forward direction
B. reverse direction
C. Both direction
D. None of the above
Explanation: A heat pump is basically a heat engine run in the reverse direction. In other words, a heat pump is a device that is used to transfer heat energy to a thermal reservoir. They are often used to transfer thermal energy by absorbing heat from a cold space and releasing it to a warmer one.
Heat pumps transfer heat from ____________ to a ______________ by the expense of mechanical energy supplied to it by an external agent.
A. hot body, hot body
B. hot body, cold body
C. cold body, cold body
D. cold body, hot body
Explanation: Heat pumps transfer heat from cold body to a hot body by the expense of mechanical energy supplied to it by an external agent.
A heat pump generally comprises ______ key components.
Explanation: A heat pump generally comprises four key components which include a condenser, a compressor, an expansion valve and an evaporator.
The working substance used in these components is called refrigerant.
C. Can be true or false
D. Can not say
Explanation: The working substance used in these components is called refrigerant.
The performance of the heat pump is expressed by the?
Explanation: The performance of the heat pump is expressed by the coefficient of performance (K).
From 1st law of thermodynamics for the cyclic process ΔU equal to?
D. None of the above
Explanation: From 1st law of thermodynamics for the cyclic process ΔU = 0.
What is the difference between Heat Pump and Refrigerator?
A. Heat Pump Gives efficiency and refrigerator gives C.O.P.
B. Both are similar
C. Both are almost similar, just the desired effect is different
D. Work is output in refrigerator and work is input in heat pump
Explanation: Heat Pump and Refrigerator work on the same principle. Work needs to be given to get the desired effect. The characteristic which differentiates both of them is the temperature of the desired effect, heat pump desires for higher temperature whereas Refrigerator desires for lower temperature than atmospheric temperature.
How is the Relative coefficient of performance represented?
A. Theoretical C.O.P. / Actual C.O.P.
B. Actual C.O.P. / Theoretical C.O.P.
C. Theoretical C.O.P. x Actual C.O.P.
D. 1 / Theoretical C.O.P. x Actual C.O.P.
Explanation: Relative C.O.P. is the ratio of an actual to the theoretical coefficient of performance. It is used to show the deviation of C.O.P. due to the ideal state and real state conditions.
C.O.P. of the heat pump is always _____
B. less than One
C. greater than One
Explanation: The second law of Thermodynamics states that a 100% conversion of heat into work is not possible without ideal conditions. So, efficiency will be less than 1. As C.O.P. is the reciprocal of efficiency, it tends to be more than 1.
If a heat pump has a higher number then it will be more efficient and it will consume less energy.
C. Can be yes or no
D. Can not say
Explanation: Yes, If a heat pump has a higher number then it will be more efficient and it will consume less energy.