Question

Two point charges $- q$ and $+ q$ are placed at a distance of $L$, as shown in the figure.

The magnitude of electric field intensity at a distance $R ( R > > L )$ varies as :

• A. $\frac{1}{ R ^{6}}$
• B. $\frac{1}{ R ^{2}}$
• C. $\frac{1}{ R ^{3}}$
• D. $\frac{1}{ R ^{4}}$

Answer 1

Answer: (C)

It is electric dipole at large distance electric field intensity
$E=\frac{K P}{R^{3}} \sqrt{1+3 \cos ^{2} \theta} $
$\therefore E \propto \frac{1}{R^{3}}$