Question

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

1. the electric field is necessarily zero.
2. the electric field is due to the dipole moment of the charge distribution only.
3. the dominant electric field is `∞ 1/r^3`, for large r, where r is the distance from a origin in this region.
4. the work done to move a charged particle along a closed path, away from the region, will be zero.

विकल्प

• b and d

• a and c

• b and d

• c and d

Answer 1

c and d

Explanation:

From Gauss’ law, we know `oint_s` E.dS = `q_(enclosed)/ε_0` in left side equation.

The electric field is due to all the charges present both inside as well as outside the Gaussian surface. Hence if `q_(enclosed)` = 0, it cannot be said that the electric field is necessarily zero.

If there are various types of charges in a region and total charge is zero, the region may be supposed to contain a number of electric dipoles.

Therefore, at points outside the region (maybe anywhere w.r.t. electric dipoles), the dominant electric field `∞ 1/r^3` for large r.

The electric field is conservative, work done to move a charged particle along a closed path, away from the region will be zero.