Question
By defining conduction current, explain why Maxwell propounded the idea of displacement current?
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Answer
Conduction current : Current flowing by the wires joining the circuit, in the circuit is known as conduction current. Let a capacitor is charged by a current I by a battery. It is clear from the figure that during charging conduction current is flowing from left to right outside the plates of the capacitor and there is no conduction current I between the plates of the capacitor.
To remove this contradiction, Maxwell introduced a new concept of displacement current $\left(I_D\right)$ and its source to be the changing electric field between the plates of the capacitor. It has been introduced to show that current flowing outside the capacitor (conduction current, $I _{ C }$ ) is equal to the current flowing in the capacitor (displacement current, $I_D$ ). According to condition put by Maxwell, conduction current ( $I_C$ ) flows in the left plate of the capacitor and displacement current $\left(I_D\right)$ flows towards the right plate in the capacitor.
To remove this contradiction, Maxwell introduced a new concept of displacement current $\left(I_D\right)$ and its source to be the changing electric field between the plates of the capacitor. It has been introduced to show that current flowing outside the capacitor (conduction current, $I _{ C }$ ) is equal to the current flowing in the capacitor (displacement current, $I_D$ ). According to condition put by Maxwell, conduction current ( $I_C$ ) flows in the left plate of the capacitor and displacement current $\left(I_D\right)$ flows towards the right plate in the capacitor.
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