What is the main function of a transformer in an electrical circuit?

• A. To convert AC to DC
• B. To change the voltage level
• C. To store electrical energy
• D. To measure electrical current

Answer: (B)

The primary function of a transformer in an electrical circuit is to change the voltage level of alternating current (AC) electricity. Transformers utilize electromagnetic induction to transfer electrical energy between two or more coils of wire, known as windings. By varying the number of turns in the primary coil compared to the secondary coil, a transformer can increase (step-up) or decrease (step-down) the voltage reaching the load.

This ability to adjust voltage levels is crucial for efficient power transmission over long distances, ensuring that electricity can be delivered at higher voltages, which reduces energy losses due to resistance in the conductors, and then transformed back down to safer, usable levels for end-users.

While the other options describe processes or devices that are important in electrical engineering, they do not directly relate to the core function of a transformer. Converting AC to DC is the role of a rectifier, storing electrical energy typically pertains to capacitors or batteries, and measuring electrical current is the job of an ammeter. Understanding the specific role of a transformer highlights its importance in electrical distribution systems and helps clarify its distinct function compared to other electrical components.