A plane electromagnetic wave travels through a non-conducting medium of relative permittivity εr=5.0 and relative permeability μr=1.0. At a point in the medium the instantaneous electric field is given by E=20j^sin(kx−ωt)V m−1, and the wave propagates along the positive x-axis.
(i) State the unit vector direction of the accompanying magnetic field at this point.
(ii) Calculate the amplitude of the magnetic field.