Question

Why the net current is conduction current plus drift current? Basically in the previous chapter we learnt about impedence is R+iX.As such why should it be not = ic+ I.d or square root of Ic square plus I'd square, just like impedence?

Answer 1

In a circuit with a capacitor,conduction current and displacement current are equal.
Note that conduction current: current in conductors due to flow of electron under applied electric potential.
Also displacement current: current b/w two plates of capacitors, due to electric field.

So in the wires of the circuit we have condution current and no displacement current.
But inside the capacitor we have displacement current but no conduction current.
So overall we are having a constant current.

We take their sum only when we take loop to find magnetic field using ampere's cicuit law.
In the loop we have both wire and capacitor,hence both condution and displacement current.
So the net current is their sum.

Hope it's clear.