What is a Live Circuit?

A live circuit is a circuit which has power actively passing through it.

This means that the power source which is the powering the circuit is turned on, and the circuit has current passing through it.

Live circuits have a notorious reputation as being seen as dangerous circuits, because there is great risk of receiving a shock from them because of the current actively going through them. This is why electricians and even electronic technicians do not operate on live circuits. Normally, they will shut off or disconnect the power source which powers the circuit. This eliminates the risk of being shocked by current, because once the power source is disconnected, there is no longer any curren t passing through the circuit to receive a shock from.

An example of a live circuit is the circuit below:

As long as the voltage source is turned on, the circuit is live, because the switch is closed. Because the switch is closed, current can flow through it and the load that needs to be powered will receive its power.

The same circuit as above, only with the switch now open, is shown below:

This circuit is not live, because the switch is open. Therefore, current cannot flow through it, since it has a break.