Asolid sphere of radius r carries charge q distributed uniformly throughout its volume. find the potential difference from the sphere's surface to its center.

The potential difference from the sphere's surface to its center is zero.

Explanation:

The expression for the potential difference due to charge is as follows;

Here, is the potential difference, q is the charge, r is the position and is the absolute permittivity of free space.

In the given problem, a solid sphere of radius r carries charge q distributed uniformly throughout its volume.

To find the potential difference from the sphere's surface to its center. Put r=0 in the expression of the potential difference.

Therefore, the  potential difference from the sphere's surface to its center is zero.

two charges are fixed in place on the x-axis as shown. the charge at x = 0 is negative and has magnitude q = 2 μcoulombs (1 μcoulomb = 10-6 coulombs). the charge at x = d, (d = +12 cm), is positive and has magnitude q = 4 μcoulombs. find a point x = xo along the x-axis at which the electric field is zero.