Electric Current

Drift velocity is defined as the average velocity that a particle attains due to an electric field.

v_%7Bd%7D%3D%5Cfrac%7Bi%7D%7Bne%20%5C%2CA%7D

where

i

is current,

n

the number of electrons,

e

the electron charge and

A

the area of crosssection of wire.
Number of electrons per unit volume

n%3D%5Cfrac%7B2%20%5Ctimes%2010%5E%7B21%7D%7D%7BA%20%5Ctimes%20100%7D

Hence, current in the wire

i%3Dne%20%5C%2CA%20v_%7Bd%7D

i%3D%5Cfrac%7B2%20%5Ctimes%2010%5E%7B21%7D%7D%7BA%20%5Ctimes%20100%7D%20%5Ctimes%201.6%20%5Ctimes%2010%5E%7B-19%7D%20%5Ctimes%20A%20%5Ctimes%200.25

i%3D0.8%5C%2C%20A

Chapter Questions
1 MCQs