Electricity and Magnetism - SS1 Physics Past Questions and Answers - page 4

A transformer works on the principle of electromagnetic induction. It consists of two coils, the primary coil and the secondary coil, which are wound around a common magnetic core. When an alternating current (AC) is applied to the primary coil, it generates a changing magnetic field. This changing magnetic field induces an alternating voltage in the secondary coil through electromagnetic induction. The voltage induced in the secondary coil is directly proportional to the turn ratio between the two coils. This allows the transformer to step up or step down the voltage based on the ratio of turns in the coils.

Transformers have numerous applications in various industries and everyday life. Some common examples include:

• Power transmission and distribution: Transformers are used in power grids to step up the voltage for efficient long-distance transmission and step it down for distribution to homes and industries.

• Electrical appliances: Transformers are used in electronic devices such as televisions, computers, and mobile phone chargers to provide the required voltage levels for their operation.

• Industrial applications: Transformers are used in industrial equipment.