Relays are used for?

• A. To increase power outputs
• B. To store electrical charge
• C. Remote control of circuits
• D. To measure voltage directly

Answer: (C)

Relays are used to control circuits remotely by acting as a switch that’s driven by a separate, low-power signal. When the control side energizes the relay coil, it activates the switching contacts to open or close the high-power circuit. This lets a small control circuit safely and remotely manage a larger load, while also providing electrical isolation between the control side and the load.

This is the best fit because it captures the core purpose of a relay: using a small input to control a larger circuit, enabling remote operation and automation. It isn’t about increasing power, storing charge, or measuring voltage directly—functions better handled by other components like power amplifiers, capacitors, or voltmeters.