Question

Why is the efficiency of a machine always less than 100 percent?

Answer 1

Because of friction.

Step-by-step explanation:

Efficiency is always less than 100% because there is always energy loss in each and every process. This loss is in the form of friction. Also, since friction is the core reason that the mechanical world exist. We even can't walk on the road if the friction is not present. Hence, we can't deny from the fact that

it also reduces the efficiency from 100%.

Answer 2

The efficiency of a machine is always less than 100 percent because there is always loss of energy in every process. It is impossible to achieve a 100 percent efficiency in all processes that we have. The energy lost is in the form of light or heat energy.