Kirchhoff’s Laws
Kirchhoff came up with two (some may say rather obvious) laws concerning conservation in electrical circuits.
Captain Obvious’ First Law
Electric charge is conserved in all circuits, all the charge that arrives at a point must leave it.
Current going in = current going out.
In the diagram we can say that: I1 = I2+ I3 + I4
Captain Obvious’ Second Law
Energy is conserved in all circuits, for any complete circuit the sum of the emfs is equal to the sum of the potential differences.
Energy givers = energy takers.
In the diagram we can say that: ε = pd1 + pd2 + pd3 + pd4.