Question

How does drift velocity of electrons in a metallic conductor vary with the rise of temperature?

Answer 1

Drift velocity is defined as the average velocity with which a free electron reach the positive terminal of the external electric field applied to the conductor.On the way, the electron has to face collisions with the positive ions of the conductor. When temperature of the conductor is increased; amplitudes of oscillations of positive ions increase, which in turn makes an electron to face more and more collisions with the positive ions of the conductor, resulting decrease in its drift velocity.Hence an increase in temperature implies decrease in the drift velocity of free electrons in a metallic conductor and vice versa.Obviously, increase in temperature will also increase the resistivity of the conductor.

Answer 2

Explanation:

As the temperature increases more electrons collide with each other in less time and hence relaxation time(T) decreases. Drift velocity(vd) is directly propotional to relaxation time from the formula vd=eET/m. so as T decreases vd also decreases.

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