Question

Find the electric field due to charge density of 1/18 and distance from a point P is 0.5 in air(in 10^9 order)

(a) 0

(b) 1

(c) 2

(d) 3

This question was posed to me in an interview for internship.

Origin of the question is Method of Images in section Electrostatic Boundary Value Problem of Electromagnetic Theory

Answer 1

Right choice is (c) 2

The best I can explain: The electric field for this case is given by, E = ρl/2πεd. Put ρl = 1/18 and d = 0.5. We get E = 2 x 10^9 units.