Question

Explain the term ‘drift velocity’ of electrons in a conductor. Hence obtain the expression for the current through a conductor in terms of ‘drift velocity’.

Answer 1

The modified velocity gained by the accelerating electrons in uniform electric field inside the conductor is called drift velocity.

The average velocity, acquired by free electrons along the length of a metallic conductor, due to existing electric field is called drift velocity.
Let n be the number density of free electrons in a conductor of length l and area of cross-section ‘A’.

Total charge in the conductor, Q=Ne
=(n Al) e
Time taken at average velocity Vd is t = 1/vd