Q. An electromagnetic wave travels along $z$-axis. Which of the following pairs of space and time varying fields would generate such a wave
A) $E_{x},B_{y}$
B) $E_{y},B_{x}$
C) $E_{z},B_{x}$
D) $E_{y},\ B_{z}$
Explanation
(a) $E_{x}$ and $B_{y}$ would generate a plane EM wave travelling in $z$-direction. $\overrightarrow{E},\ \overrightarrow{B}$ and $\overrightarrow{k}$ form a right handed system $\overrightarrow{k}$ is along $z$-axis. As $\widehat{i} \times \widehat{j} = \widehat{k}$
$\Rightarrow E_{x}\widehat{i} \times B_{y}\widehat{j} = C\widehat{k}\ i.e.E$ is along $x$-axis and $B$ is along $y$-$axis$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.