Question

Define the term 'drift velocity' of charge carriers in a conductor and write its relationship with the current flowing through it.

Answer 1

In a current-carrying conductor, a charged particle is accelerated by an electric field. It also undergoes frequent collisions with the stationary ions of the wire material. These two effects result in a very slow net motion (drift) of moving charged particles in the direction of the electric force. This motion is described by the drift velocity(v_d).
The relationship of drift velocity with current is given by \[v_d = \frac{I}{neA}\]

Here:
I is the current following through the conductor.
n is the number density of an electron.
A is the area of the conductor.
e is the charge of the electron.