What component in a solenoid returns the plunger to its original position?

The plunger spring is the component that returns the plunger to its original position in a solenoid. When the solenoid is activated, an electromagnetic field is generated that pulls the plunger into the coil. Once the power is removed and the electromagnetic field dissipates, the plunger is no longer held in place by the magnetic force. The plunger spring then provides the mechanical force necessary to move the plunger back to its starting position. This mechanical action is essential for the solenoid to function effectively in applications such as switching devices, where it is important for the plunger to return reliably after activation.

Choosing the plunger spring highlights the importance of mechanical components in solenoid operation, as it complements the electromagnetic aspect by providing the necessary return force when the solenoid is deactivated.