An electric dipole of dipole moment p is aligned parallel to a uniform electric field E. The energy required to rotate it through an angle θ is:
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An electric dipole of dipole moment p is aligned parallel to a uniform electric field E. The energy required to rotate it through an angle θ is:

G1 Physics · Accepted Answer

Step 1: Dipole potential energy U(θ) = −pE cosθ. Step 2: Initially aligned, U(0) = −pE. Step 3: Work required = U(θ) − U(0) = pE(1 − cosθ).