Fig. 23-1 shows equipotentials surrounding a pair of charges QA and QB. The value of the potential half-way between the charges is indicated. Which of the statements below applies to the charges?
Nothing can be said about the charges.
The two charges have opposite signs and different magnitudes.
The two charges have opposite signs and equal magnitudes.
The two charges have the same sign and equal magnitudes.
The two charges have the same sign but different magnitudes.