-->

Current Electricity

Question
CBSEENPH12038082

Suppose that the electric field part of an electromagnetic wave in vacuum is E = {(3.1 N/C) cos [(1.8 rad/m) y + (5.4 × 106 rad/s)t]}i^.  Write an expression for the magnetic field part of the wave.

Solution

Electric field E = {(3.1 N/C) cos [(1.8 rad/m) y + (5.4 × 106 rad/s)t] i 
 
Expression of magnetic field part of the wave
 B = B0 cos (ky + ωt)    = 1.03 × 10-8 cos 1.8 rad/m y + (5.4 × 106 rad/s) t

E is along i^ and c is along -j,
c is the direction of E × B
             -j^ = i^ × ?
Clearly B is in the direction of k^k^×i^ =j^ and i^ × k^ =-j^
Thus,
B is completely represented as,

B = 1.03 × 10-8 cos(1.8 rad/m)y + (5.4 × 106 rad/s)tk^.

Some More Questions From Current Electricity Chapter