Three point charges $+q,-2 q$ and $+q$ are placed at points $(x=0, y=a, z=0),(x=0, y=0, z=0)$ and $(

Question

Three point charges $+q,-2 q$ and $+q$ are placed at points $(x=0, y=a, z=0),(x=0, y=0, z=0)$ and $(x=a, y=0, z=0)$ respectively. The magnitude and direction of the electric dipole moment vector of this charge assembly are

Professor PC Thomas Classes · Answer

This consists of two dipoles, $-q$ and $+q$ with dipole moment along with the $+y$-direction and $-q$ and $+q$ along the $x$-direction.

$	herefore \quad$ The resultant moment $=\sqrt{q^{2} a^{2}+q^{2} a^{2}}=\sqrt{2} q a$.
Along the direction $45^{\circ}$ that is along $O P$, where $P$ is $(+a,+a, 0)$.