Question

A plane electromagnetic wave travels in vacuum along z- direction. What can you say about the directions of ots electric and magnetic field vectors. If the frequency of the wave is 30 MHz, what is its wavelength?

Answer 1

Answer:

the electric and the magnetic felies are along X and Y direction and are not so specified and the wave length can be found as below

Explanation:                      velocity=wavelenght*f

                                        f=frequency

                                         v=velocity of light

Answer 2

The wavelength of the wave is

Explanation:

Given :

Frequency $f = 30 \times 10^{6}$ Hz

⇒ Electromagnetic waves are transverse type of wave.

⇒ In case of transverse wave electric field vector and magnetic field vector are perpendicular to each other.

From the basic formula of frequency,

  $v = f \lambda$

  $\lambda = \frac{v}{f}$

Where $v =$ speed of light

  $\lambda = \frac{3 \times 10^{8} }{30 \times 10^{6} }$        ( ∵ $v = 3 \times 10^{8} \frac{m}{s}$ )

  $\lambda = 10$ m

Therefore, the wavelength is 10 m