Question

In a uniform electric field E, the work done in rotating the electric dipole of dipole moment P from $-45^{\circ}$ to $45^{\circ}$ with respect to the field direction is

• A. 0.5 PE
• B. 0.414 PE
• C. 0.866 PE
• D. PE
• E. zero

Hint:

Logic Tip: The potential energy of a dipole depends strictly on $\cos\theta$. Any rotation between two symmetric angles (like $-\theta$ to $+\theta$) results in the dipole returning to an identical potential energy state, meaning the net work done by the external agent over the complete path is exactly zero.

Answer 1

Answer: (E)