Each of the following heat engines is missing one of the thr

Each of the following heat engines is missing one of the three energy flows necessary. Explain why each one is physically impossible or otherwise undesirable. (a) (b) (c)

Solution

Case 1.

The first case is physically impossible because with out any heat gain from higher reservoir how a heat engine produced work.This is practically or physically impossible.

Case 2.

The second case also be physically impossible because It is impossible to construct a device which operating on a single reservoir and continously producing work.Minimum two reservoir is compulsory for produce work.because

!!There is nothing like a 100% efficient heat engine!!

Perpetual motion machine of the second kind is not possible.

Case 3.

The third case is undesirable. because in third case the heat is gain from higher temperature reservoir totaly goes to lower reservoir there zero work produce so that such kind of heat engine is undesirable which is not producing work or we can se who zero efficiency.