Switches

What happens when you walk into a dark room and flip the light switch? The light turns on because you have completed the circuit! A switch is a device that opens or closes a circuit and either prevents or allows the current to flow through the circuit. 

Here’s another way to think about it … a switch uses conductors and insulators to make and break the circuit.  When the switch is on, the two conductors touch and the path is complete. When the switch is off, the path is broken.