Introduction to Electrodynamics · Problem 4.8

Electric Fields in Matter — David J. Griffiths

Physics · dipole-dipole-interaction-energy

Problem

Show that the interaction energy of two dipoles separated by a displacement r\mathbf{r} is U=14πϵ01r3[p1⋅p2−3(p1⋅r^)(p2⋅r^)].(4.7)U = \frac{1}{4\pi\epsilon_0}\frac{1}{r^3}[\mathbf{p}_1 \cdot \mathbf{p}_2 - 3(\mathbf{p}_1\cdot\hat{\mathbf{r}})(\mathbf{p}_2\cdot\hat{\mathbf{r}})]. \tag{4.7} [Hint: Use Prob. 4.7 and Eq. 3.104.]

Related theory

Browse the problem library