Three equal negative point charges -q are placed at three of the corners of a square of side d as shown in the figure.Which one of the arrows shown represents the direction of the net $\vec { E }$ field at the vacant corner of the square?

Question

Quizplus · Accepted Answer

By symmetry, we can see that the two bottom charges will cancel out each others field horizontally, and the right charge will "push" the top charge down vertically. Thus the direction of the net E field at the empty corner will be downwards, as shown by arrow B.

Three Equal Negative Point Charges -Q Are Placed at Three E⃗\vec { E }E

Three Equal Negative Point Charges -Q Are Placed at Three $\vec { E }$