Question

In $\vec{E}$ and $\vec{K}$ represent electric field and propagation vectors of the EM waves in vacuum, then magnetic field vector is given by: $(\omega-$ angular frequency):

• A. $\frac{1}{\omega}(\bar{K} \times \bar{E})$
• B. $\omega(\overline{ K } \times \overline{ E })$
• C. $\bar{K} \times \bar{E}$
• D. $\omega(\overline{ E } \times \overline{ K })$

Answer 1

Answer: (A)

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