WHY CURRENT LAGS IN INDUCTIVE LOAD?

Inductor stores the electrical energy in magnetic field in other words the current passing into the inductor is not equal to the current coming out of the inductor meanwhile the voltage across the output terminal remains constant or unaltered due to which the voltage across the load develops before the current reaches the end of the load. It therefore lags the voltage by some angle called "phi"

By physical realization when a voltage is applied across an inductor, the inductance is proportional to the ratio of 'time rate of change of magnetic flux' to the 'time rate of change of electric current'. This is the rate of change of flux with respect to the current. According to Lenz law in electro-magnetism, this inductance will oppose the change of the quantity which create it. Hence the inductance prevents the change in current passing through the inductor and this will leave the current lagging the voltage. The more the inductance, the larger is the time-lag angle...