Two charges -q and +q are located at points (0, 0, –a) and (0, 0, a), respectively.
(a) What is the electrostatic potential at the points (0, 0, z) and (x, y, 0) ? (b) Obtain the dependence of potential on the distance r of a point from the origin when `r//a gt gt 1`.
(c) How much work is done in moving a small test charge from the point (5,0,0) to (–7,0,0) along the x-axis? Does the answer change if the path of the test charge between the same points is not along the x-axis?

Two point charges -q and +q are located at points (0,0-a) and (0,0,a) resepctively.The electric potential at point (0,0,z) is (Z gt a)

Two point charges q and –q are at positions (0,0,d) and (0,0, –d) respectively . What is the electric field at (a,0,0 ) ?

Two point charges q and - q are located at points (0 , 0 , - a ) and (0 , 0 , a) respectively : (a) Find the electrostatic potential at (0 , 0 , z) and ( x , y , 0). (b) How much work is done in moving a small test charge from the point (5 , 0 , 0 , ) to (-7 , 0 , 0 ) along the x - axis ? (c) How would your answer change if the path of the test charge between the same points is not along the x axis but along any other random path ? (d) If the above point charges are now placed in the same position in a uniform external electric field vecE , what would be the potential energy of the charge system in its orientation of unstable equilibrium ? Justify your answer in each case .

Two charges +q and -q are located at points A(0,0. -2) and B(0,0,2) respectively. How much work will be done in moving a test charge from point P (4,0,0) and Q(-5,0,0) ?

Two charges -q and + q are located at points A (0, 0, -a ) and B(0, 0 + a ) . How much work is done in moving a test charge from point (b, 0, 0 ) to Q (-b, 0, 0) ?