Question

A charge Q is placed at each of the opposite corners of a square. A charge q is placed at each of the other two corners. If the net electrical force on Q is zero, then Q/ q equals –

• A. $- 2\sqrt{2}$
• B. – 1
• C. 1
• D. $- \frac{1}{\sqrt{2}}$

Answer 1

Answer: (A)

$- 2\sqrt{2}$

Answer 2

Since net force on charge Q is zero (Placed at corner A).

+ $\left[ \sqrt { 2 } \frac { \mathrm { kQq } } { \mathrm { a } ^ { 2 } } \right]$ = 0

Ž =

Ž = $- 2 \sqrt { 2 }$

So option (1) is correct.