Apoint charge, magnitude q, is at the origin of a coordinate system. a second charge q is brought to distance r from the charge from a very large distance away, then is taken in a semicircle around the charge so that it is opposite where it was but at the same distance, then brought out to distance 2r. what is the work done on the moving charge by the electric field of the first charge?
(a)
w=qq/(8 pi epsilon_0 r)
(b)
w = qq/(4 pi epsilon_0 r)
(c)
w = qq/(16 pi epsilon_0 r)
(d)
w=0