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 $\vec{B}=\frac{1}{\omega}(\vec{K} \times \vec{E})$