Question

Electric charges $q,q, - 2q$ are placed at the corners of an equilateral triangle $ABC$ of side$l$. The magnitude of electric dipole moment of the system is

• A. $ql$
• B. $2ql$
• C. $\sqrt{3}ql$
• D. $4ql$

Answer 1

Answer: (C)

$\sqrt{3}ql$

Answer 2

$p_{net} = \sqrt{p^{2} + p^{2} + 2pp\cos 60{^\circ}} = \sqrt{3}p = \sqrt{3}ql$ ( p = ql)