An electric dipole of moment p is placed in a uniform field E. The wor…

Question

An electric dipole of moment p is placed in a uniform field E. The work done to rotate it from the orientation θ = 0 (aligned with the field) to θ = 180° is

Accepted Answer

A. {'text': '2pE', 'label': 'A'}

1. PE in a uniform field: U(θ) = −p·E = −pE cos θ.
2. W = ΔU = U(180°) − U(0°) = (+pE) − (−pE) = 2pE.
3. The dipole goes from the most stable to the least stable orientation; work is positive on the system.
_Source: NCERT Class 12 Physics Part I, Ch 2 §2.8.3_

Answer

{'text': '0', 'label': 'B'}

Answer

{'text': '−2pE', 'label': 'C'}

Answer

{'text': 'pE', 'label': 'D'}