📘 electrostatics

1. Statement of the problem. We are given point sources at positions $\mathbf{r}_i$ with strengths $\theta_i$, and an observation point $\mathbf{r}$, and we want the total electric

1. Problem statement: A solid conducting sphere of radius $a$ has net charge $2Q$. A concentric conducting spherical shell with inner radius $b$ and outer radius $c$ has net charge