Question

Let $E_{ a }$ be the electric field due to dipole in its axial plane at distance $l$ and let $E_{\text {eq }}$ be the field in the equatorial plane at a distance $l'$, then the relation between $E_{a}$ and $E_{ eq }$ will be

• A. $E_{ a }=4 E_{\text{eq}}$
• B. $E_{\text{eq }}=2 E_{ a }$
• C. $E_{ a }=2 E_{\text{eq }}$
• D. $E_{ a }=E_{ eq / 3}$

Answer 1

Answer: (C)

We know that
$E_{( a )}=\frac{1}{4 \pi \varepsilon_{0}} \frac{2 p}{r^{3}} $ (on axial line)
and $ E_{\text {(eq) }}=\frac{1}{4 \pi \varepsilon_{0}} \frac{p}{r^{3}}$ (on equatorial line)
Therefore, $E_{\text {(a) }}=2 E_{\text {eq }}$