Question

Two point charges have a charge of +1.7 microcoulumbs each. One of the charges is placed in the upper left corner of a square and the other is placed in the lower right corner of the square. A third charge is then fixed at the center of the square. The third charge causes the electric potentials at the empty corners of the square to change signs without changing magnitudes.
a. Draw a diagram.
b. Determine the electric potential at one of the empty corners before the third charge is inserted (find your answer in terms of variables).
c. Find the sign and magnitude of the third charge.

Answer 1