Kirchhoff's Rules

Ohm's law by itself, $V=IR$, is only directly useful for simple circuits containing a single loop and a single source of emf. Real circuits are frequently far more complex, with multiple loops, multiple junctions and possibly multiple emf sources, and for these, Kirchhoff's rules provide a complete, systematic method for finding every unknown current and voltage. There are two such generalised rules: (i) Kirchhoff's current rule (also called the junction rule), which applies at every branch point of a circuit, and (ii) **Kirchhoff's …