At which of the following points is the electric field least in magnitude?

Question

Two positive charges of magnitude q are each a distance d from the origin A of a coordinate system as shown above.

At which of the following points is the electric field least in magnitude?

(A) A 

(B) B 

(C) C 

(D) D 

(E) E

Answer 1

The correct option is: (A) A 

Explanation:

Since both charges are positive, the electric field vectors point in opposite directions at points between the two. At point A, the magnitudes of the electric field vectors are equal and therefore cancel out, making E = 0 at point A.