Question

two short electric dipoles P₁ and P₂ are placed at an angleθ and r is the distance between their centres. The energy of electric interaction between these dipoles will be :

Answer 1

$\text{U}=-\frac{p_{\text{1}}{p}_{\text{2}}}{\text{4}\pi {ϵ}_0{\text{r}}_{12}^3}(\text{cos}{\theta }_{12}-\text{3cos}{\theta }_{\text{1}}\text{cos}{\theta }_{\text{2}})$


Here,

​θ₁₂ = angle made by the two dipoles
r12 = the distance between the two dipoles at center.
Also,
θ₂ = the angle formed by the 2nd dipole w.r.t the line connecting their centers.