The potential at a point x (measured in mm) due to some charges situated on the x-axis is given by V(x) = 20/(x2 – 4) volt The electric field E at x = 4μm is given by
(a) (10/9) volt/μm and in the +vex direction
(b) (5/3) volt/μm and in the –vex direction
(c) (5/3) volt/μm and in the +vex direction
(d) (10/9) volt/μm in the –vex direction
