Which of the following pairs of space and time -varying E and B fields generate a plane electromagnetic wave traveling along z -direction ?

Options

A. `E_(x), B_(y)`
B. `E_(y), B_(x)`
C. `E_(x), B_(yz)`
D. `E_(y), B_(zx)`

Answer

B

Explanation

The direction of propagation of electromagnetic wave is perpendicular to the plane in which the electric field and the magnetic field are oscillating.

Mathematically, the direction of propagation of electromagnetic wave is given by:
`rArr vecE xx vecB`
The result of the cross product of electric and magnetic field is `-hatk` as per question.
By vector product rule:
`hatj xx hati =-hatk`
Therefore, the elctric field should be in y axis and the magnetic field should be in x axis.