Consider a region inside which there are various types of charges but the total charge is zero ,.At points outside the region

Options

A. the electric field is necessarily zero.
B. the electric field is due to the dipole moment of the charge distribution only.
C. the dominant electric field is inversely proportional to `r^(3), for large r (distance from origin).
D. the work done to move a charged particle along a closed path, away from the region will not be zero.

Answer

C

Explanation

When there are various types of charges in a region, but the total charge is zero, the region can be supposed to contain a number of electric dipoles. Therefore, at point outside the region, the dominant electric field `prop1/r^(3)` for large r.