What device operates on the principle of mutual induction to change voltage and current magnitudes?

• A. Rectifier
• B. Inductor
• C. Transformer
• D. Capacitor

Answer: (C)

The correct answer is a transformer, as it operates on the principle of mutual induction to change voltage and current levels in electrical circuits. Transformers are instrumental in the transmission and distribution of electrical power, as they allow for the efficient transfer of electrical energy between circuits.

When alternating current (AC) flows through one coil of wire (the primary coil), it creates a varying magnetic field. This magnetic field then induces an electrical current in a nearby coil of wire (the secondary coil), which allows the transformer to either step up (increase) or step down (decrease) voltage levels depending on the turns ratio of the coils. This capability is crucial for adjusting voltage levels to minimize energy loss during transmission over long distances and to suit the requirements of different electrical devices.

In contrast, rectifiers convert AC to direct current (DC) and do not change voltage and current through mutual induction. An inductor is primarily used for storing energy in a magnetic field and does not inherently change voltage and current as a transformer does. Capacitors store energy in an electric field and also do not operate through the principle of mutual induction. Thus, the function and operational principle of a transformer distinctly align with the process of mutual induction, solidifying its role in voltage and current transformation in