Electrostatics AdvancedHardQuestion 31490
Question
A charge distribution has zero monopole moment (total charge = 0) and zero dipole moment. The dominant far-field potential is:
- A∝ 1/r
- B∝ 1/r²
- C∝ 1/r³Correct
- DZero everywhere
Correct answer
∝ 1/r³
Explanation
With Q = 0 and p = 0, the quadrupole term dominates: V_quadrupole ∝ 1/r² and E_quadrupole ∝ 1/r³. Example: two dipoles back-to-back.