Behaviour of AC Circuits

In dc circuits, voltage and current are constant w.r.t time. The solution of the circuit may be attemted simply by applying ohm's law i.e. I=V/R. In ac circuits, voltage applied to the circuit (V) and current flowing through it (I) change from instant to instant. Thus, the above simple relation will not hold good in these circuits. The Variation of current w.r.t time set up magnetic effects and variation in emf set up electrostatic effects. Both these effects, must be taken into account while dealing with ac circuits. Magnetic effects will be appreciably large with low voltage, heavy current circuits. Electrostatic effects are usually appreciable with high voltage circuits.