Define and explain Kirchhoff's Junction Rule. Provide three (3) examples of its use

Kirchhoff's Junction Rule, also known as Kirchhoff's First Law or Kirchhoff's Current Law (KCL), states that the total current entering a junction or a node in a circuit must equal the total current leaving the same junction or node. This law is a consequence of the conservation of electric charge.

In other words, the sum of currents in a network of conductors meeting at a point (node or junction) is always zero. This is because a junction or node in a circuit is a point of connection for two or more paths in the circuit, and the current has no other place to go but to follow these paths.

Here are three examples of its use:

1. Simple Series Circuit: In a simple series circuit with a battery and two resistors, the current flowing from the battery is the same current flowing through each resistor. This is because there is only one path for the current to flow. This is a direct application of Kirchhoff's Junction Rule.

2. Parallel Circuit: In a parallel circuit with a battery and two resistors, the current from the battery splits at the junction to flow through each resistor. The current through each resistor may be different, but the total current leaving the battery is the sum of the currents through each resistor. This is an application of Kirchhoff's Junction Rule at the junction where the current splits.

3. Complex Circuit: In a more complex circuit with multiple junctions and paths, Kirchhoff's Junction Rule can be used at each junction to solve for unknown currents. By setting up a system of equations based on the Junction Rule, you can solve for the unknowns. This is a more advanced application of Kirchhoff's Junction Rule.