Kirchoff's 1st Law

Key Stage 5

Kirchoff's 1st Law states that the total current entering a junction is equal to the total current leaving the junction.

Also known as the current law or junction rule.
Kirchoff's 1st Law is based on the conservation of charge.
Kirchoff's 1st Law is essential for analyzing complex electrical circuits.
In Kirchoff's 1st Law the algebraic sum of currents at a junction is equal to zero.
Kirchoff's 1st Law helps in solving circuit problems by setting up equations based on current conservation.
Kirchoff's 1st Law is used in network analysis techniques such as mesh analysis and nodal analysis.
Kirchoff's 1st Law applies to both DC and AC circuits.

In a parallel circuit, the sum of currents through each branch equals the total current entering the junction.
Used to determine unknown currents in electrical network problems.