Electric Circuits and Networks

2.2 KIRCHHOFF'S CURRENT LAW (KCL)

The law of conservation of charge states that charges can neither be created nor destroyed in a given volume. Hence, if the positive charge that flows into a volume at any instant t exceeds the positive charge that flows out of the volume at the same instant, then, the net charge stored inside the volume must be increasing at that instant. Similarly, if the positive charge that flows out of the volume exceeds the positive charge that flows into the volume at that instant, then, the net charge stored within must be decreasing at that instant. Therefore, the net positive current that flows into the volume at an instant t must be equal to the rate of change of net charge stored within that volume at that instant. ...