Electromagnetic Waves Question 1
Question 1 - 24 January - Shift 1
If $\overrightarrow{{}E}$ and $\overrightarrow{{}K}$ represent electric field and propagation vectors of the EM waves in vacuum, then magnetic field vector is given by: ( $\omega$ angular frequency) :
(1) $\frac{1}{\omega}(\overrightarrow{{}K} \times \overrightarrow{{}E})$
(2) $\omega(\overrightarrow{{}E} \times \overrightarrow{{}K})$
(3) $\omega(\overrightarrow{{}K} \times \overrightarrow{{}E})$
(4) $\overrightarrow{{}K} \times \overrightarrow{{}E}$
Show Answer
Answer: (1)
Solution:
Formula: Maxwell’s Equations
Magnetic field vector will be in the direction of
$\hat{K} \times \hat{E}$
magnitude of $B=\frac{E}{C}=\frac{K}{\omega} E$
Or $\vec{B}=\frac{1}{\omega}(\vec{K} \times \vec{E})$
