Electricity transformers

Electricity transformers are used to "transform", or change, electricity from one voltage to another. Voltages can be increased or decreased.

A transformer consists of two or more coils of wire wound around an iron core. The coils are usually contained in an oil-filled tank, which insulates and cools them.

When electricity is supplied to the primary coil, it magnetises the core and produces a voltage in the secondary coil. The voltage produced depends on the ratio of the number of turns in each coil. If the ratio of the number of turns on the primary coil to the number of turns on the secondary coil is 1:5, then the voltage produced across the secondary coil will be five times the voltage of the primary coil. If the ratio of the number of turns on the primary coil to the number of turns on the secondary coil is 10:1, then the voltage produced across the secondary coil will be one-tenth the voltage of the primary coil.

An iron core has ten turns of a primary coil and two turns of a secondary coil of wire

An iron core has three turns of a primary coil and six turns of a secondary coil of wire