The electric potential field V at a point, due to two charged particles, is given by

 

where q₁ and q₂ are the charges of the particles in coulombs (C), r₁ and r₂ are the distances of the charges from the point (in meters), and ,0 is the permittivity of free space, whose value is

Suppose the charges are q₁ = 2 × 10^-10 C and q₂ = 4 × 10^-10 C. Their respective locations in the xy plane are (0.3, 0) and (-0.3, 0) m. Plot the electric potential field on a three-dimensional surface plot with V plotted on the z axis over the ranges -0.25 ≤ x ≤ 0.25 and -0.25 ≤ y ≤ 0.25. Create the plot in two ways:

(a) By using the surf function

(b) By using the meshc function.

1 92 V 4TE0 r2