A temperature difference between two bodies is useful because:

  1. it makes mass
  2. it allows a heat engine to do work
  3. it destroys energy
  4. it increases entropy
Answer

B) it allows a heat engine to do work

Once equalised, no work can be extracted. SLO P-11-C-19 · Understanding

Physics MCQ · More Heat Engines, Second Law and Entropy MCQs · Practise