What are practical applications of electromagnetic induction?

Electromagnetic induction is used in power generation, transformers, induction motors, wireless charging, and induction cooking.

Electromagnetic induction is the principle behind the generation of electricity in power plants. In a typical power plant, a turbine is used to rotate a large magnet inside a coil of wire. As the magnet rotates, it creates a changing magnetic field which induces an electric current in the wire. This is known as Faraday's law of electromagnetic induction, a cornerstone concept that you can explore in greater detail here. The electric current is then transmitted through power lines to homes and businesses.

Transformers, which are used to increase or decrease the voltage of alternating current (AC), also operate on the principle of electromagnetic induction. A transformer consists of two coils of wire, the primary coil and the secondary coil, wound around a common iron core. When an AC voltage is applied to the primary coil, it creates a changing magnetic field in the core. This changing magnetic field induces a voltage in the secondary coil. The ratio of the number of turns in the primary coil to the number of turns in the secondary coil determines whether the transformer increases or decreases the voltage. Discover more about how transformers work by visiting this page.

Induction motors, which are commonly used in industrial applications, also utilise electromagnetic induction. In an induction motor, a rotating magnetic field is created in the stator (the stationary part of the motor) by applying an AC voltage. This rotating magnetic field induces a current in the rotor (the rotating part of the motor), which creates its own magnetic field. The interaction between these two magnetic fields causes the rotor to rotate. This application is a practical demonstration of electromagnetic induction, further detailed here.

Wireless charging technology, such as that used in some smartphones and electric toothbrushes, is another application of electromagnetic induction. In wireless charging, a changing magnetic field is created by passing an AC current through a coil in the charging base. This changing magnetic field induces a current in a second coil in the device being charged, which is used to charge the device's battery.

Finally, induction cooking hobs use electromagnetic induction to heat pots and pans. In an induction hob, a coil of wire is energised with a high-frequency AC current, creating a changing magnetic field. This magnetic field induces eddy currents in the pot or pan, which heat it up. The hob itself remains cool, making induction cooking safer and more energy-efficient than traditional cooking methods. For an in-depth look at how electromagnetic induction facilitates this process, refer to electromagnetic induction in cooking.