What is the role of relays in electrical circuits?

• A. To regulate voltage
• B. To enable low current to control high current
• C. To store energy
• D. To convert AC to DC

Answer: (B)

Relays act as electromechanical switches that let a small, low-current control signal govern a much larger current in a separate circuit. When the relay coil is energized, its magnetic field moves contacts to open or close the load circuit, so the high-current device—like a motor or heater—can be turned on or off without running that heavy current through the control wiring. This setup also provides isolation between the control side and the high-power side, protecting sensitive control electronics. Relays don’t regulate voltage, store energy, or convert AC to DC, so the description about enabling low current to control high current best captures their function.