Question

The magnetic field of an electromagnetic wave in a substance is given by B = (2 x 10^-6 T) cos[pi(0.04x + 10^7t)],

Answer 1

B = (200μT)Sin[(4 x 1015 5–1) (t – x/C)]

(a) B0 = 200μT

E0 = C x B0 = 200 x 10–6 x 3 x 108 = 6 x 104

(b) Average energy density  = 0.0159 = 0.016.