The drift velocity of electron in a metal conductor under effective of elecrtic field applied is

The value of drift velocity of electrons in a metal is about

How does drift velocity of electrons in a metallic conductor change, if the length of the conductor is doubled by stretching it, keeping the applied voltage constant?

Derive the expression for drift velocity of free electron in terms of relaxation time and electric field applied across a conductor.

Derive the expression for drift velocity of free electron in terms of relaxation time and electric field applied across a conductor.