Explain how much efficiency of an ideal machine compares with the efficiency of a real machine?

Answer 1

An ideal machine has, by definition, an efficiency of exactly 100%, which means that absolutely none of the energy it consumes is wasted when converted to power (energy per unit of time), hence the name "ideal". A real machine, however, will never reach an efficiency of 100%, as there will always be at least a tiny bit of energy that is lost to the environment. This is because it is practically impossible to create a perfectly closed system in which no energy can leak out. It is possible, however, to build very efficient systems and machines, although this depends on just how well they are made. Therefore, the efficiency of a real machine is quite variable, going easily from 10% to 98%, depending on its quality. A simple example is that of ordinary household voltage Transformers, which generally have efficiencies of around 80%; and of high grade power plant transformers, which have efficiencies of around 98%.