Domestic: 240 V AC, 50 Hz
Industrial: 400 V AC, 50 Hz
Plugs used for 240 V: BS-546 and BS-1363
the voltage of the mains electricity in the UK
In the UK the mains voltage is 240 volts
The mains voltage is 230 volts, and the frequency is 50Hz.
The main function of an electric circuit is to provide a path for electrons to flow. The electrons are from a current source flow or voltage.
To supply the bell, because the latter has a rated voltage that's lower than the mains.
220V
A 'service mains' is not associated with an electricity 'transmission' system, but with a low-voltage 'distribution' system. The service mains is the name given to the cable that connects a building to the low-voltage mains supply.
You get power, which is voltage * current (so both!).
230 V
Less likelihood of electrocotion.
3 Point (british)
Desktop computers all come with a power supply that changes the mains voltage in your country's electricity supply to that needed inside the PC. Thus the Voltage used by your PC is the mains voltage in the country where the PC was sold.