In Frame 1, Two Identical Conducting Spheres, a and B

Multiple Choice

In Frame 1, two identical conducting spheres, A and B, carry equal amounts of excess charge that have the same sign. The spheres are separated by a distance d; and sphere A exerts an electrostatic force on sphere B that has a magnitude F. A third sphere, C, which is handled only by an insulating rod, is introduced in Frame 2. Sphere C is identical to A and B except that it is initially uncharged. Sphere C is touched first to sphere A, in Frame 2, and then to sphere B, in Frame 3, and is finally removed in Frame 4. Determine the magnitude of the electrostatic force that sphere A exerts on sphere B in Frame 4.

A) F/2
B) F/3
C) 3F/4
D) 3F/8
E) zero