• A fictitious machine that produces net work in a complete cycle by exchanging heat with only one reservoir is called the PMM2.
• It violates the Kelvin-Plank statement.
• Thus, it violates the second law of thermodynamics and It is a hypothetical machine.

Perpetual motion machine of the first kind (PMM1):

• The first law of thermodynamics states that energy can neither be created nor be destroyed. It can only get transformed from one form to another form.
• An imaginary device which would produce work continuously without absorbing any energy from its surroundings is called a Perpetual Motion Machine of the First kind, (PMMFK).
• A PMMFK is a device which violates the first law of thermodynamics. It is impossible to devise a PMMFK.
• The converse of the above statement is also true, i.e., there can be no machine that would continuously consume work without some other form of energy appearing simultaneously.
• PMM-I violates the first law of thermodynamics.