Where transformer is used?

A transformer is an electrical machine whose purpose is to either 'step up' or 'step down' a voltage. For example, the voltage generated by an alternator in a power station is far too low for transmission, so a 'step up' transformer is used to increase that voltage to transmission levels. Transmission voltages are then gradually reduced, using 'step down' Transformers at load centres (e.g. towns) where the electricity is to be used.