Question

Several electric field line patterns are shown in the diagrams below. Which of these patterns are incorrect?
(A)
(B)
(C)
(D)
(E)

Answer 1

For answering this question, we need to use the properties of the electric field lines emerging from a point charge. The electric field lines emerge from a positive charge and terminate at the negative charge. Also, for a point charge they possess spherical symmetry.

Formula used: The formula used to solve this question is given by
$E = \dfrac{{KQ}}{{{r^2}}}$ , here $E$ is the electric field due to a point charge $Q$ at a distance of $r$ from it, and $K$ is a constant.

Complete step-by-step solution
We know that the electric field lines emerge out of the positive charge, while they terminate at the negative charge.
From the electric field line pattern given in the option C we can see that the field lines are terminating at the positive charge. So this field line pattern must be incorrect.
Therefore, option C is correct.
Also, in the electric field line pattern given in the option E, we can see that the field lines are emerging out of the negative charge. So this field line pattern is incorrect.
So the option E is also correct.
Also, we know that the electric field around a point charge is given by
$E = \dfrac{{KQ}}{{{r^2}}}$
Here $r$ is the distance of a point from the point charge. We know that the locus of all the points located at a distance $r$ from the point charge is a sphere of radius $r$ , which is centred at the point charge. So the electric field at each point on each of the concentric spheres, centred at the point charge, must be constant. This means that the electric field lines due to a point charge must possess spherical symmetry.
In the field line pattern given in the option D, we can see that the electric field lines are more concentrated on the right side than on the left side. So this means that the magnitude of the electric field is more at the right side than on the left side. Thus, there is no spherical symmetry. Therefore, this electric field line pattern must also be incorrect.
So the option D is also correct.
Hence, the correct options are C, D, and E.

Note
Make sure you tick the options which correspond to the incorrect electric field line pattern, as stated in the question. It is a natural psyche to tick those options correct which correspond to the correct fact. So we must read the question carefully and tick the options accordingly.