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Electrostatics

Dipole field

Derive the expression for the electric field on the axial line of an electric dipole of dipole moment p at a point distance r from its center.

SA

Medium

4 Marks

75% Confidence

Confidence Score

75%

Times Viewed

0

Max Marks

4

Hints

1.consider two charges +q and -q separated by 2a
2.use superposition of fields
3.take limit as a -> 0, qa = p

Answer Outline

1.Electric field from +q and -q at axial point
2.Superpose: E = (1/4πε₀)[q/(r-a)² - q/(r+a)²]
3.Simplify and use dipole moment p=2qa
4.Result: E = (1/2πε₀) × (p/r³) along axis

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