A refrigerator works by
Correct answer: B. using work to move heat from a cold interior to the warmer room
- A. creating cold and pumping it into the cabinet
- B. using work to move heat from a cold interior to the warmer room
- C. destroying heat inside the cabinet
- D. lowering the entropy of the universe
Explanation
Heat does not flow from cold to hot on its own, so a compressor does work to drive it that way, which is why the pipes at the back of the fridge feel warm. There is no such thing as cold to pump; only heat is moved. The room as a whole ends up warmer, because the energy removed plus the work done is all dumped into it.
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About First Law of Thermodynamics
The first law relates heat supplied, work done and the change in internal energy through energy conservation. Problems use sign conventions and apply the law to isothermal, adiabatic, isobaric and isochoric processes. Internal energy is a state function, while heat and work depend on the path followed.
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