Question

A plane electromagnetic wave propagating along $y-$direction can have the following pair of electric field $\left(\overrightarrow{E}\right)$ and magnetic field $\left(\overrightarrow{B}\right)$ components -

• A. $E_x,B_z$ or $E_z,B_x$
  
• B. $E_y,B_x$ or $E_x,B_y$
  
• C. $E_y,B_y$ or $E_x,B_x$
  
• D. $E_y,B_y$ or $E_z,B_z$
  

Answer 1

The correct option is A $E_x,B_z$ or $E_z,B_x$



We know that, $\hat{c}=\hat{E}\times \hat{B}$.

So, if $c$ is along $+y$ direction then $E$ can be along $z$ and $B$ along $x$.
Hence, $(E_z,B_x)$ is possible.

Similarly, if $c$ is along $-y$ direction then $E$ can be along $x$ and $B$ along $z$.
Hence, $(E_x,B_z)$ is also possible.

Therefore, option $\left(A\right)$ is correct.