Question

The magnitude of electric field intensity at point $\left(\right.2,0,0\left.\right)$ due to a dipole of dipole moment, $\overset{ \rightarrow }{P}=\hat{i}+\sqrt{3}\hat{j}$ kept at origin is :

• A. $\frac{\sqrt{13} K}{8}$
• B. $\frac{\sqrt{13} K}{4}$
• C. $\frac{\sqrt{7} K}{8}$
• D. $\frac{\sqrt{7} K}{4}$

Answer 1

Answer: (C)

$\overset{ \rightarrow }{P}=\hat{i}+\sqrt{3}\hat{j}$
$\left|\right.\overset{ \rightarrow }{P}\left|\right.=2$
Electric field at $\left(\right.2,0,0\left.\right)$ is
$E=\frac{K P \sqrt{3 cos^{2} \theta + 1}}{r^{3}}$
$=\frac{K \left(\right. 2 \left.\right) \sqrt{3 \left(cos\right)^{2} 60 + 1}}{8}$
$=\frac{\sqrt{7} K}{8}$