In the rectangle shown below, the two comers have charges q1 = -5 μC and q2 = +2.0 μC. The work done in moving a charge +3.0 μC from B to A is (take1/4πε0=1010 N-m2/C2)
2.8 J
3.5 J
4.5 J
5.5 J
Work done W=3×10-6VA-VB; where VA=1010-5×10-615×10-2+2×10-65×10-2=115×106 volt and VB=10102×10-615×10-25×10-65×10-2=-1315×106 volt ∴ W=3×10-6115×106--1315×106=2.8 J