Answer:

Explanation:
The electrostatic potential energy is given by the following formula

Now, we will apply this formula to both cases:

So, the change in the potential energy is

This problem uses the relationships among current
I, current density
J, and drift speed
vd. We are given the total of electrons that pass through the wire in
t = 3s and the area
A, so we use the following equation to to find
vd, from
J and the known electron density
n,
so:

<span>The current
I is any motion of charge from one region to another, so this is given by:
</span>

The magnitude of the current density is:

Being:

<span>
Finally, for the drift velocity magnitude vd, we find:
</span>
Notice: The current I is very high for this wire. The given values of the variables are a little bit odd
The direction of magnetic field lines get reversed as the direction of magnetic field lines is from north pole to south pole
Average speed = distance travelled / time used