It is<em> impossible</em> to construct a machine which produces the<em>work output greater than the work input.</em>
Let us consider the II law of thermodynamics.
According to Kelvin Plank's statement any engine/machine does not give hundred percent efficiency. And violating the PMM-II(Perpetual motion of machine II kind), Always some amount of energy transferred to the sink or surroundings.
Therefore
W(ouput) = Q₁-Q₂
There are many reasons to lower the work output, just for an example friction between the mating parts reduces the work output.
A machine makes are work easier. The mechanical advantage of a machine tells us the ability of machine to multiply the input force. No machine is 100% efficient. It means it cannot convert all the input completely to output, let alone give a greater output. Some of the work that is input into the machine is always lost in overcoming friction produced.
