How do transformers change voltage levels in circuits?

Transformers change voltage levels in circuits by using electromagnetic induction to step up or step down the voltage.

A transformer is a device that uses the principle of electromagnetic induction to change the voltage level in an electrical circuit. It consists of two coils of wire, known as the primary coil and the secondary coil, which are wound around a common iron core. The primary coil is connected to the input voltage source, while the secondary coil is connected to the load.

When an alternating current (AC) flows through the primary coil, it creates a changing magnetic field around the coil. This changing magnetic field induces a voltage in the secondary coil. The amount of voltage induced in the secondary coil depends on the ratio of the number of turns in the primary coil to the number of turns in the secondary coil, known as the turns ratio.

If the secondary coil has more turns than the primary coil, the transformer is called a step-up transformer. In this case, the voltage induced in the secondary coil is greater than the input voltage. This is because the increased number of turns in the secondary coil allows for more of the magnetic field to be captured and converted into electrical energy, resulting in a higher voltage.

On the other hand, if the secondary coil has fewer turns than the primary coil, the transformer is called a step-down transformer. In this case, the voltage induced in the secondary coil is less than the input voltage. This is because the reduced number of turns in the secondary coil captures and converts less of the magnetic field into electrical energy, resulting in a lower voltage.

In summary, transformers change voltage levels in circuits by using the principle of electromagnetic induction and the turns ratio of the primary and secondary coils to either step up or step down the voltage.