Induction furnace Wikipedia
Power supplies range from 10 kW to 42 MW, with melt sizes of 20 kg to 65 tonnes of metal respectively. [citation needed] An operating induction furnace usually emits a hum or whine (due to fluctuating magnetic forces and magnetostriction), the pitch of which can be used by operators to identify whether the furnace is operating correctly or at what power level. [citation needed] See also