When no current pass through the conductor:

see full answer

Your Exam Success, Personally Taken Care Of

1:1 expert mentors customize learning to your strength and weaknesses – so you score higher in school , IIT JEE and NEET entrance exams.

An Intiative by Sri Chaitanya

The free electron do not move

The average speed of a free electron over a large period of time is zero

The average velocity of free electron over a large period of time is zero

The average velocities of free electrons at an instant is zero

answer is C.

(Unlock A.I Detailed Solution for FREE)

Best Courses for You

JEE

NEET

Foundation JEE

Foundation NEET

CBSE

Detailed Solution

Concept- Even when no current is flowing through the conductor, electrons are in random motion due to thermal excitation. As a result of the random motion, their net velocity is 0.
Even when no current is flowing through them, free electrons do not move because the conductor has the thermal energy that excites the electron.
Because speed is a scalar variable, the electron's average speed will not be 0. So it does not cancel out even after all random motion.
When no electric field is provided, electrons move at random. As a result, the net electron displacement is zero. As a result, the sum of the velocities attained by the electrons while in motion is also zero. The average velocity of one electron over a longer period will also be zero.
Because the average velocity of one free electron is zero, the total of average velocities is also zero. As a result, the average velocity of all electrons will be zero. Another way to put it is that because the net current in the conductor is zero, the displacement for all electrons is also zero. This implies that they have no drift velocity. As a result, the average velocity of free electrons at any time is zero.
Hence, the correct option is 3,4.

Watch 3-min video & get full concept clarity