Question

The magnetic field of a plane-polarized electromagnetic wave moving in the z-direction is given by in SI units. What is the frequency of the wave

Answer 1

Complete Question    

The magnetic field of a plane-polarized electromagnetic wave moving in the z-direction is given by

$B=1.2* 10^{-6} sin [2\pi[(\frac{z}{240} ) - ( \frac{t * 10^7}{8} ) ] ]$    in SI units.

Answer:

The  value  is  $f = 1.98918*10^{5}\ Hz$

Explanation:

From the question we are told that

   The magnetic field is    $B=1.2* 10^{-6} sin [2\pi[(\frac{z}{240} ) - ( \frac{t * 10^7}{8} ) ] ]$

 This above  equation can be modeled as

       $B=1.2* 10^{-6} sin [2\pi[(\frac{z}{240} ) - ( \frac{t * 10^7}{8} ) ] ] \equiv A sin ( kz -wt )$

So  

       $w = \frac{10^7}{8}$

Generally the frequency is mathematically represented as

       $f = \frac{w}{2 \pi}$

=>    $f = \frac{ \frac{10^7}{8} }{2 \pi}$

=>    $f = 1.98918*10^{5}\ Hz$