Acharge q of magnitude 6.4 × 10^-19 coulombs moves from point a to point b in an electric field of 6.5 × 10^4 newtons/coulomb. the distance between a and b is 1.2 × 10^-2 meters and the path between a and b is parallel to the field. what is the magnitude of the difference in potential energy?

a. 1.2 × 10^-15 joules
b. 2.3 × 10^-15 joules
c. 3.2 × 10^-15 joules
d. 6.4 × 10^-15 joules
e. 6.4 × 10^-14 joules

Explanation:

The potential difference between point A and point B is given by:

where

is the electric field strength

is the distance between point A and B

Substituting, we find

Now we can calculate the difference in potential energy, which is given by

where

is the charge.

Substituting, we find

the answer is the first electromagnet (a). this is because it has more coils around the ferromagnetic material. increasing the number of coils increases the surface area in which the metal interacts with the current in the coil. this enables more atoms in the metal to become aligned hence becoming more magnetized.