According to BBC History, Michael Faraday is best known for his discovery of electromagnetic inductance, which is the principle behind the electric transformer, generator and motor. His ideas on electricity developed into what is known as Faraday's law. His work was crucial in transforming electricity from a curiosity to a powerful new technology.
Faraday's law describes how a magnetic field in an electric circuit produces a voltage. This is typically demonstrated by wrapping two wires on opposite sides of an iron ring, then applying a current through one wire, which creates a magnetic field, causing an electrical effect in the other wire.
An electrical transformer works in a similar manner, based on the same principle. It uses the magnetic field from a current flowing through a primary winding device to create either a larger or a smaller voltage in a secondary winding mechanism. In power grids, this function increases the voltage from the power station in order to transmit it through the power wires. As the electricity reaches its destination, the voltage decreases to a safe level to power homes and businesses.
Electric generators and motors both have a wire coil in a magnet field, according to Boston University Physics Department. In the motor, current is passed through the coil, generating a magnetic field that causes the coil to spin. In the generator, the coil is spun mechanically, which induces a current and a voltage in the coils.