Poistive and negative point charges of equal magnitude are kept at `(0, 0, a/2)` and `(0, 0, (-a)/(2))` respectively. The work done by the electric field when another poistive point charge is moved from `(-a, 0, 0)` to `(0, a, 0)` is

Options

A. Positive
B. Negative
C. Zero
D. Depends on the path connecting the initial and final positions

Answer

C

Explanation

Point A(-a,0,0) on xaxis :
`V_A=0`
`V_A=0`
Because distance is same and sum of charges = 0
Point B (0, a,0) on y-axis :
`V_B =0`
Distance is same and sum of charges = 0.