A few electric field lines for a system of two charges `Q_1` and `Q_2` fixed at two different points on the x-axis are shown in the figure. These lines suggest that

Options

A. (a) `|Q_1|gt|Q_2|`
B. (b) `|Q_1|lt|Q_2|`
C. (c) at a finite distance to the left of `Q_1` the electric field is zero
D. (d) at a finite distance to the right of `Q_2` the electric field is zero

Answer

A, D

Explanation

The electric field lines are orginating from `Q_1` and terminating on `Q_2`. Therefore `Q_1` is positive and `Q_2` is negative.
As the number of lines associated with `Q_1` is greater than that associated with `Q_2`, therefore `|Q_1|gt|Q_2|`.
Option (a) is correct.
At a finite distance on the left of `Q_1`, the electric field intensity cannot be zero because the electric field created by `Q_1` will be greater than `Q_2`. This is because the magnitude of `Q_1` is greater and the distance smaller `[EpropQ/r^2]`
At a finite distance to the right of `Q_2`, the electric field is zero. Here, the electric field created by `Q_2` at a particular point will cancel out of the electric field created by `Q_1`.