In figure two positive charges `q_(2)` and `q_(3)` fixed along the y-axis ,exert a net electric force in the `+x` direction on a charge `q_(1)` fixed along the x-axis if a positive charge `Q` is added at `(x,0)` the force on `q_(1)`

Options

A. Shall increase along the positive x-axis
B. Shall decrease along the positive x-axis
C. Shall point along the negative x-axis
D. Shall increase but the direction changes because of the intersection of Q with `q_2 and q_1`

Answer

A

Explanation

The net force on `q_1` by `q_2` and `q_3` is along the + x - direction, so nature of force between `q_1, q_2 and q_1, q_3` is attractive. This can be represent by the figure give, below

The attractive force between these charges states that `q_1` is a negative charge (since, `q_2` and `q_3` are positive)
Thus, nature of force between `q_1` and newly introduced charge Q (positive) is attractive and net force on `q_1` by `q_2,q_3` and Q are along the same direction as given in the diagram below

The figure given above clearly shows that the force on `q_1` shall increase along the positive x-axis due to the positive charge Q.