A transformer works on the principle of electromagnetic induction, which states that a changing magnetic field induces an electromotive force (EMF) in a conductor.
A transformer consists of two coils of wire, known as the primary and secondary winding, which are wound around a laminated iron core. When an alternating current (AC) flows through the primary winding, it creates a magnetic field that constantly changes direction, and this magnetic field induces an EMF in the secondary winding. The voltage induced in the secondary winding depends on the ratio of the number of turns in the primary and secondary windings.
If the secondary winding has more turns than the primary winding, the voltage in the secondary winding will be higher than the voltage in the primary winding. If the secondary winding has fewer turns than the primary winding, the voltage in the secondary winding will be lower than the voltage in the primary winding.
Transformers are used to change the voltage of an AC power supply, by stepping the voltage up or down to the required level. This is achieved by using a transformer with the appropriate ratio of primary to secondary turns. Transformers are used in power transmission and distribution, as well as in electronic devices, such as power supplies and audio equipment.