Kirchhoff's Current Law at Circuit Nodes

Kirchhoff's Current Law explains how current behaves at a circuit node. A node is the point where two or more circuit elements meet. The law says the current entering a node equals the current leaving it. That balance follows the rule of charge conservation, which means electric charge is not lost at the junction.

Kirchhoff's current law, or KCL, is based on the law of charge conservation. It states that the total current entering and leaving a node in a circuit is equal.

Currents leaving the node have a minus sign, while currents entering the node have a plus sign.

By algebraically summing the currents at a node and integrating both sides w...