nothing
No
It is possible that the waffle maker will operate on a 220v 50hz power supply, but there is a risk that it may not function optimally or may overheat. It is recommended to check the manufacturer's specifications or contact them directly to confirm compatibility.
Yes, you can use a voltage converter to step up the voltage from 110V to 220V. However, changing the frequency from 50Hz to 60Hz is more complex and may require a frequency converter, which can be costly and may not be practical for all applications.
you can't
The voltage and frequency range depends on the individual appliance, but each appliance should have a small plaque on it near where the power cord enters, telling you the working range.
Yes, no problem.
220v 50Hz
Nothing happens. The stereo has a transformer that converts the power to DC, and 50 or 60 Hz input makes no difference.
There should be no problem at all.
220V , 50Hz
One way would be to hook it up to a supply (by itself, with no load) and measure the speed with a contact tachometer. If your supply is 60Hz, and the motor speed corresponded to one of the standard motor speeds, it would be a pretty safe bet you had a 60Hz motor. If the speed was about 20% faster than a standard speed, the motor is probably a 50Hz motor. Or 20% slower if you were running a 60Hz motor on 50Hz For instance, a 1750 RPM 50Hz motor would spin at about 2100 RPM if you ran it on 60Hz.