Real-Life Application

Electrical current traveling through coils creates a magnetic field within the coils. This principle is used regularly in the operation of mechanical doors and valves. A solenoid is a device that consists of an electric coil and a metal bar resting just outside of the coil. When a current is applied to the coil, a magnetic field forms and pulls the metal bar into the center of the coil. Any mechanical door that unlocks when a button is depressed operates by use of a solenoid. The metal bar is the deadbolt and the magnetic field pulls it out of place.