Answer:
f = 23.43 Hz for radio waves.
Explanation:
In this case, we need to find the frequency of an electromagnetic wave having a wavelength equal to Earth’s diameter i.e. 12,800 km. The relation between the frequency, wavelength and the speed is given by :
[tex]v=f\lambda[/tex]
Electromagnetic wave moves with a speed of light
[tex]c=f\lambda[/tex]
[tex]f=\dfrac{c}{\lambda}[/tex]
[tex]f=\dfrac{3\times 10^8}{12800\times 10^3}[/tex]
f = 23.43 Hz
So, the frequency of an electromagnetic wave is 23.43 Hz. It belongs to radio waves.
