An inventor claims to have developed an engine that takes in 1000 J of heat and produces 1500 J of work during each cycle.The proposed engine claims to produce more work in a cyclic process than the amount of heat that is supplied, so it is in violation of the first law of thermodynamics.
The first law of thermodynamics is a version of the law of conservation of energy, adapted for thermodynamic systems. The law of conservation of energy states that the total energy of an isolated system is constant; energy can be transformed from one form to another, but can be neither created nor destroyed. The first law is often formulated.
ΔU=Q−W.