Summary
Highlights
Transformers are crucial for the national grid. Electricity generated at large power stations is passed through step-up transformers, increasing the voltage to about 400,000 volts to minimize energy loss during transmission across the country. Once it reaches its destination, like a town, step-down transformers reduce the voltage to around 230 volts for safe use in homes.
A transformer consists of an iron core connecting a primary coil on one side to a secondary coil on the other. The key function of a transformer is to increase or decrease the voltage of electricity.
An alternating potential difference applied to the primary coil creates a current and an alternating magnetic field. This alternating magnetic field induces an alternating magnetic field in the iron core. Finally, the iron core's magnetic field induces a potential difference across the secondary coil, causing current to flow. The current is transferred through induced magnetic fields, not direct electrical conduction because the wires are insulated.
The number of turns in the coils determines whether a transformer steps up or steps down the voltage. A step-up transformer has more turns in the secondary coil than the primary coil, increasing the voltage. Conversely, a step-down transformer has fewer turns in the secondary coil, decreasing the voltage.