Question

What do you understand by the term drift velocity of electrons. How is this diffferent from the velocity of current in a conductor?

Answer 1

• In any conductor, there are positively charged ions at rest and negatively charged electrons which are free.
• When an emf is applied to such a conductor, the electrons start moving from the negative terminal to the positive terminal. However, the speed of their free flow is reduced by the postive ions along their path and thus are said to be drifting.
• The average velocity acquired by electrons in a current carrying conductor is referred to as drift velocity.
• It is usually of the order of 0.001 m/s and is different from the velocity of current in the conductor, which is almost equal to the speed of light.