can we use frequency above or less than 50hz for machines

Any machine is designed to run on a particular frequency, current and voltage. Any variation in these parameters may not provide the desired output. Although current and voltage will not be sharp values, but a range. So it is better to operate the machine at right frequency itself.

thk u ...😁

The normal 50Hz convention we use is a compromise between the needs of lighting and of electromechanical applications.Let me make it straight. Using low frequencies(15-25Hz) in motors can give the best efficiency. That's because the electrical humming is reduced(Please view a detailed explanation in Wikipedia, search for AC machines, electric hum, and related topics). But if we use the same low frequency for lighting applications, we can get flickering(poor) light. For light, we have to use high frequency for good quality light. So, a compromise is done by bringing the frequency to a value of 50Hz(in India). All the machines are designed accordingly(so as to give maximum efficiency at 50Hz). I believe this answer sheds in more light. I will be happy if this answer has come to use for you.