The tensor $\sigma_{ij}$ is the flux of the $j$th component of electromagnetic <momentum> across a surface normal to the $i$ direction, with the sign convention used in the conservation law. Its diagonal components are normal <momentum> fluxes, interpreted as electromagnetic <pressures> or tensions. Its off-diagonal components are tangential <momentum> fluxes, interpreted as shear stresses.

Solution

Past exam of the mathematics course of the University of Cambridge / 2024 / ii / Paper 3 / 36D / b / Solution

 Solution (source code)