A plane electromagnetic wave propagating along x-direction can have the following pairs of E and B.
(a) Ex, By
(b) Ey, Bz
(c) Bx, Ey
(d) Ez, By
1. (b, c)
2. (a, c)
3. (b, d)
4. (c, d)
(3) Hint: The direction of the electromagnetic wave is perpendicular to both the electric field and the magnetic field.
Step 1: Find the direction of the electric field and the magnetic field.
As electric and magnetic field vectors E and B are perpendicular to each other as well as perpendicular to the direction of propagation of the electromagnetic wave. Here in the question, the electromagnetic wave is propagating along the x-direction. So, the electric and magnetic field vectors should have either y-direction or z-direction.
