Question

give me four conditions for a machine to be ideal machine?

Answer 1

A machine which is 100% efficient is called an ideal machine.
When total input energy is converted in to work, machine is said to be ideal machine.
When heat produced by the machine is zero, machine is said to be ideal machine.
When frictional force is reduced to zero, then there is no energy loss , machine is said to be ideal machine.
When input power is equal to the output power then machine is said to be ideal machine.