A small electric dipole p→=10−9 i^ N/C is placed at the origin. A(1,0m) and B(0,1m) are two points. Then (VA−VB) is

x-axis is the equatorial line of the dipole and potential of any point on the equatorial line is zero. Hence VB=0 and VA=14π∈0.pr2=9×109×10−9(1)2V=9 volt∴  VA−VB=9 volt.