Question

(i) Derive an expression for drift velocity of free electrons.

(ii) How does drift velocity of electrons in a metallic conductor vary with increase in temperature ? Explain.

Answer 1

(i) When a potential difference is applied across a conductor, an electric field is produced and free electrons are acted upon by an electric force. Due to this, electrons accelerate and keep colliding with each other and acquire a constant (average) velocity v_d

(ii) Decreases, as time of relaxation decreases