Question

Q: The potential energy of a dipole Eext is​

Answer 1

♡♡The potential energy of a dipole Eext is-------

P.E=−pEcosθ=−p⋅E. This is negative when θ is acute and positive when θ is obtuse.

●●● EXTRA NOTE●●●

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The state where the dipole is pointing in the same direction as the electric is lower than that where the two vectors are anti-parallel, so you want the θ=0∘ state to be lower than the θ=180∘ state. So you insert the negative sign to enforce that.

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Answer 2

$\huge{\mathfrak\red{Answer}}$

The potential energy of a dipole is

${\red{P.E=−pEcosθ=−p⋅E}}$

This is negative when θ is acute and positive when θ is obtuse.

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