Question

Consider the four cases of a heat engine satisfies the first law (energy equation) and if it violates the second law and determine if any of those are perpetual machines of the first or second kind.

Answer 1

| | 1st law | 2nd law |
| a | Yes | Yes (possible) |
| b | Yes | No, impossible Kelvin - Planck Perpetual machine second kind It violates the 2nd law converts all Q to W |
| c | No | Yes, but energy not conserved Perpetual machine first kind It generates energy inside |
| d | Yes | Yes (Irreversible Q. over ∆T) |