Why US uses 120V

UK outlets provide a frequency of 50 Hz. Transformers do not provide a conversion to US 60 Hz ; you are stuck with UK 50 Hz. The only electrical products that need concern you regarding this frequency mismatch are products that contain motors (i.e. things that run fans, spin wheels, rotate things, etc.

At the end of the day, however, there are no major differences between 50Hz and 60Hz . They’re both equally valid power supply standards, and whether you use one over the other will depend more on your circumstances rather than the pros and cons of either.

Originally Answered: What happen if I use a 60 hz appliance in 50 hz? Generally 60 hz appliance are designed for 110v and 50 hz appliance are for 220-240. In this case if you use 60 hz appliance in 50 hz, it’ll burn(if there is no over voltage protection circuit) .

In Great Britain, the grid frequency is 50Hz . In the US, it’s 60Hz. In Japan, the western half of the country runs at 60Hz, and the eastern half of the country runs at 50Hz – a string of power stations across the middle of the country steps up and down the frequency of the electricity as it flows between the two grids.