Engines, Heat Pumpts and Refrigerators Formula

Question 1

efficiency of a heat engine

Answer 1

e = |W| / |Q[h]|

where |W| = magnitude of work done, and |Q[h]| = magnitude of input heat energy

Question 2

maginitude of heat energy (assuming no othter losses)

Answer 2

|Q[h]| = |W| + |Q[c]|

where |Q[h]| = magnitude of input heat energy, |W| = magnitude of work done, and |Q[c]| = magnitude of rejected heat

Question 3

efficiency of heat engine (assuming no heat lost)

Answer 3

e = 1 - |Q[c]| / |Q[h]|

Question 4

efficient of Carnot Engine

Answer 4

e = 1 - |Q[c]| / |Q[h]| = 1 - T[c] / T[h]

where T[c] = temperature of cold reservoir, and T[h] = temperature of hot reservoir

Question 5

efficiency of reverse heat engine

Answer 5

e = |Q[c]| / |W|

Question 6

energy deposited in hot reservoir (for refrigeration process)

Answer 6

|Q[h]| = |W| + |Q[c]|