or Kirchhoff's laws
Two statements, developed by Gustav Kirchhoff , about complex circuits that embody the laws of conservation (see conservation law ) of electric charge and energy.
They are used to determine the value of the electric current in each branch of the circuit. The first law states that the sum of the currents into a junction in the circuit equals the sum of the currents out of the junction. The second law states that around each loop in an electric circuit, the sum of the electromotive force is equal to the sum of all the potential drops (changes in voltage) across components in the loop. Using these rules, algebraic equations can be formulated to determine the value of currents in different loops in a circuit.