Question:-
A plane wave having the electric field component E®i = 24cos (3 x 108t - by)s^z v/m and traveling in free space is incident normally on a lossless medium with
m = m0and e=9e0 which occupies the region y¡Ý0. The reflected magnetic field component is given by
Option (A)
(1 /10p) cos(3 x 108t + y)a^x A/m
Option (B)
(1/20p) cos(3 x 108t + y)a^x A/m
Option(C)
-(1/20p) cos(3 x 108t + y)a^x A/m
Option(D)
-(1/10p) cos(3 x 108t + y)a^x A/m
Correct Option:
(A)
Question Solution:

r = [40-120] p / [40+120] p = (-1/2)

\ r = -Ve `E will change direction & M will not change its direction

direction of `M for incident field is in x, so direction of `M in the reflected field is also is in x.

|Mc| = (|Ei r| / h) = {(24x(1/2)) / 120 p} = (1/10 p)
question-answer-faq-2185