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 `prop(1)/(r^(3))` for large `r`, where `r` is the distance from a origin in this region
D. the work done to move a charged particle along a closed path ,away form the region will be zero

Answer

C,D

Explanation

The electric field at points outside the origin is due to all the lndividual charges and their distribution over the region.As the total charge is zero ,the region can be supposed to contain a number of dipoles .For a point outside the region ,the dominant electric field is due to dipoles.ie.e `prop (1)/(r^(3)` for large `r`. Also as the electric field is conservation ,the work done to move a charged particle along a closed path is zero.options (c ) and (d) are correct.