2.12 A charge of 8 mC is located at the origin. Calculate the work done in taking a small charge of from a point P (0, 0, 3 cm) to a point Q (0, 4 cm, 0), via a point R (0, 6 cm, 9 cm).
Given,
The initial distance between two charges
The final distance between two charges
Hence total work is done
The path of the charge does not matter, only initial and final position matters.