Explain, using Faraday’s law of induction, how the transformer steps down the voltage.

Faraday's law of electromagnetic induction states that a change in the magnetic field within a closed loop of wire induces an electromotive force (EMF) in the wire. This is the fundamental principle behind the operation of a transformer.

Here's how a transformer steps down voltage:

1. A transformer consists of two coils of wire, known as the primary and secondary windings, wrapped around a common iron core. The primary winding is connected to the input voltage source, while the secondary winding is connected to the load.

2. When an alternating current (AC) is passed through the primary winding, it creates a changing magnetic field around the coil. This changing magnetic field is also linked with the secondary winding because they are both wrapped around the same iron core.

3. According to Faraday's law, the changing magnetic field induces an EMF in the secondary winding. The magnitude of this induced EMF (or voltage) is directly proportional to the rate of change of the magnetic field and the number of turns in the secondary winding.

4. The ratio of the number of turns in the primary winding to the number of turns in the secondary winding determines whether the transformer steps up or steps down the voltage. If the secondary winding has fewer turns than the primary winding (as in a step-down transformer), the induced voltage in the secondary winding will be less than the input voltage in the primary winding.

5. Therefore, by carefully choosing the number of turns in the primary and secondary windings, a transformer can be designed to step down (or step up) the voltage as required.

Remember, a transformer only works with AC voltage because it relies on a changing magnetic field to induce voltage. It will not work with direct current (DC) because the magnetic field created by a DC voltage does not change.