Question

The absolute potential at the center of a square is 3. V when a charge of +Q is located at one of the square's corners. What is the absolute potential at the square's center when a second charge of -Q is placed at one of the remaining corners?

A) -6 V
B) -12 V
C) 6 V
D) Zero
E) 12 V

Answer 1

The correct answer is D, V =0

Step-by-step explanation:

The electrical potential due to a point charge is given by

V = k ∑
`q_(i) / r_(i)`

Let's apply this equation to our case

V = k (Q / r - Q / r)

V = 0

Since the two charges have the same magnitude and are of opposite signs and the distance from any corner to the center of the square from side to is

r = √2 a/2

Therefore all distances are equal

The correct answer is D