Real heat pumps never reach the ideal coefficient of performance found for a Carnot cycle between the same two temperatures. According to the source, what range of COPhp values do real heat pumps typically achieve?
AAbout 1 to 2
BAbout 2 to 4
CAbout 5 to 8
DAbout 8 to 12
Answer & Solution
Correct answer: B. About 2 to 4
1. The ideal, Carnot-based heat pump in the source's worked example reaches a COPhp of 5.30, well above what real hardware achieves.
2. It is stated that real heat pumps do not perform quite as well as this ideal case.
3. It gives the typical range for real heat pumps directly: values of COPhp range from about 2 to 4.
4. The other listed ranges, 1 to 2, 5 to 8 and 8 to 12, do not match this stated range.
_Source: OpenStax College Physics (CC BY 4.0), Ch 15 "Thermodynamics", section 15.5 Applications of Thermodynamics: Heat Pumps and Refrigerators_
Related questions
A perfect crystal at 0 K has W equal to 1, which makes its entropy:Boltzmann's model related the entropy of a system to which quantity?An endothermic process that involves an increase in system entropy is spontaneous when temA process whose enthalpy and entropy changes share the same arithmetic sign will show:At minus 10.00 degrees Celsius the entropy change of the universe for melting is negative,Melting is described as spontaneous at 10.00 degrees Celsius because at that temperature:Free energy is described as the energy available to do useful work, being the difference bBesides indicating spontaneity, the free energy change gives information about the amount