What effect does energizing a relay coil have on the connected load side of the circuit?

• A. It decreases supply voltage to the motor.
• B. It increases current draw on control side.
• C. It pulls in associated contacts to control other devices, providing isolation and signal amplification.
• D. It stores energy for later release.

Answer: (C)

Energizing the relay coil creates a magnetic field that moves the armature, pulling the relay contacts on the load side to change the state of the load circuit. This allows a small control signal to switch a larger load current, providing isolation between the control and load circuits and enabling signal amplification. The coil’s action doesn’t change the supply voltage to the load directly, and while the coil does draw current on the control side, that describes control-side consumption rather than what happens to the load. It’s not about storing energy for later release; the coil’s magnetic field is used to actuate the contact now.