Question

What is the wavelength of a radio photon from an "am" radio station that broadcasts at 1120 kilohertz?

Answer 1

The wavelength of the radio photon  is 268 m.

Electromagnetic waves travel with the speed of 3×10⁸m/s in vacuum. The speed of a wave c is related to its frequency f and wavelengthλ as follows:

$c=f\lambda$

Thus the wavelength is given by,

$\lambda =\frac{c}{f}$

Substitute 3×10⁸m/s for c and 1120×10³Hz for f.

$\lambda =\frac{c}{f}\\ =\frac{3*10^8m/s}{1120*10^3Hz} \\ =267.8 m\\ =268 m$

Thus the wavelength of the radio photon from an AM station is 268 m