Question

What is the function of a transformer in an a.c. circuit? How do the input and output power in a transformer compare?

Answer 1

Electric circuit is the path for the transmission of electric current. It includes a battery, the connecting wires, or the transmission lines.

Complete solution:
A transformer is a device that trades voltage for the current in a circuit and it does not affect the total electrical power. It takes high-voltage electricity with a small current and then changes it into low-voltage with a large current or else vice versa.
Thus the function of a transformer is to step-up or step-down the alternating voltage by maintaining the power at the same level. Thus the change in voltage causes reverses the change in the current Hence if the voltage becomes doubled then the current becomes halved.
The ideal transformer will not change the input waveform and also will not cause any power loss.
The main purpose of the transformer is in the transmission of electrical power over long distances. This is the main reason for which AC was adopted universally.
The voltage is stepped up at the sending end thereby transmitting the power by the thin wires. Moreover, power will be the same on the primary and secondary sides. Thus the increase in the voltage causes a reduction in the current. Similarly, at the receiving end, the voltage is stepped down to the usable levels.
Thus a step-up transformer changes low voltage electricity into high voltage electricity and a step-down transformer turns high voltage electricity into low voltage electricity.

Note: 1. There are two types of current namely Alternating Current (AC) and direct current (DC). In Alternating Current, the electrons will flow in both directions while in the case of the Direct Current, the electrons will flow in one direction.
2. The transmission of electrical power over long distances can be made more economical by using AC.