Define Drift speed. Also we know that the drift speed of a steady current carrying conductor is about 1mm/s. Then how we observe lightening fast speed of current in a typical circuit?

Asked by Akshit Wahi | 12th Sep, 2011, 12:00: AM

Expert Answer:

In a conductor, the electrons undergo frequent collisions with the ions of the material. Hence, the direction of the electrons undergoes a random change. See figure below, the net effect is that in addition to the random motion of the electrons, there is also a very slow net motion or drift of the electrons. This drift or flow with a constant velocity (in a direction opposite to ) is called the drift velocity VD.

The drift velocity of the electrons Vd is (using E = V / l)

In a circuit, when potential difference is applied, the electrons gets attracted towards the positive terminal and acquire a faster speed.

Answered by  | 13th Sep, 2011, 10:34: AM

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