Browse Questions

# Two equal charges (q each) are placed at the vertices B and D of the square ABCD (as shown in the figure). The sides of the square are of length a.What charge should be placed at the corner C, such that the electric field at A becomes zero?

$\begin{array}{1 1}(A)\;+2q \\ (B)\;-2q \\ (C)\;-2 \sqrt {2q} \\(D)\;+2 \sqrt {2q} \end{array}$

$-2 \sqrt {2q}$ is correct.