Maxwell's equations for the electric field E(r) and the magnetic field B(r) in a charge- and current-free region are: (i) (ii) V.E=0 OB t 1 8 c t -7) E 1 V.B=0 VXE By considering V (V E), use Maxwell's equations and an appropriate vector identity to show that - E = 0 Hence obtain an expression for the constant c. Find a similar equation for the magnetic field B. V x B= 60 JE t