When reactive elements such as capacitors , inductors , or transmission lines are involved in a circuit to which AC or time-varying voltage or current is applied , the relationship between voltage and current becomes the solution to a differential equation , so Ohm 's law ( as defined above ) does not directly apply since that form contains only resistances having value R , not complex impedances which may contain capacitance ( `` C '' ) or inductance ( `` L '' ) .
Ohm 's Law shows the relationship between the voltage ( V ) , current ( I ) and resistance ( R ) .