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

Question

Consider a region inside which, there are various types of charges but the total charge is zero. At points outside the region (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 r3, 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

Tardigrade Admin · Accepted Answer

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 points outside the region, the dominant electric field propto (1/r3) for large r.

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

the electric field is necessarily zero

the electric field is due to the dipole moment of the charge distribution only

the dominant electric field is inversely proportional to $r^{3}$ , for large $r$ (distance from origin)

the work done to move a charged particle along a closed path, away from the region will not be zero

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 points outside the region, the dominant electric field $\propto \frac{1}{r ^{3}}$ for large $r$ .