A large plate of non-ferromagnetic material moves with a constant velocity `v = 90 cm//s` in a unifrom magnetic field with induction `B = 50 mT` as shown in Fig. Find the surface density of electric charges appearing on the plate as a result of its motion.

Explanation

Within the plate, there will appear a `(vec(v) xx vec(B))` force, which will cause charges inside the plate to drift, until a countervalling electric field is set up. This electric field is related to `B`, by`E = e B` since `v & B` are mutually perpendicular, and `E` is perpendicular to both. THe charge density `+- sigma`, on the force of the plate, producing this electric field, is given by
`E = (sigma)/(epsilon_(0))` or `sigma = epsilon_(0) v B = 0.40 pC//m^(2)`