Contacts are the conducting elements that open and shut the circuit. Take a simple circuit comprising a battery, a swap, and a bulb. As soon you turn the switch on, the bulb adjustments from brilliant to dim. On the other hand, when the change is turned off, it turns into very brilliant, just for a fraction of a second before turning off utterly. It is probably the best element, comprising just a coil of copper wire. The inductance is directly proportional to the variety of turns in the coil.