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 :

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 :

charges -q and +q separated by distance L

1. \(\frac{1}{R^6}\)

2. \(\frac{1}{R^2}\)

3. \(\frac{1}{R^3}\)

4. \(\frac{1}{R^4}\)

Doubtly Asked 30 Oct 2026 NEET UG 2022 Practice test neet Save WhatsApp Report

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Answer: 3. \(\frac{1}{R^3}\)

The two charges form an electric dipole with dipole moment \(p=qL\). Their fields nearly cancel at a large distance.

For \(R\gg L\), the dipole field is \(E\approx\dfrac{kp}{R^3}\) (axial or equatorial, only the factor differs), so \(E\propto 1/R^3\).

Option (3). A single charge would give \(1/R^2\).

Doubtly AI · 30 Oct 2026 AI-generated · not yet verified Report

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