Question

Am radio signals are broadcast at frequencies between 550 khz and 1600 khz and travel 2.99792 × 108 m/s. What is the shortest am wavelength? Answer in units of m.

Answer 1

Answer:

187.37 m

Explanation:

The wavelength of an electromagnetic wave is given by:

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

where

c is the speed of light

f is the frequency

We see that the wavelength is inversely proportional to the frequency: this means that the shortest am wavelength will occur at the highest am frequency, which is

$f=1600 kHz = 1600 \cdot 10^3 Hz$

And substituting also the speed of light

$c=2.99792 \cdot 10^8 m/s$

We find the wavelength:

$\lambda=\frac{2.99792 \cdot 10^8 m/s}{1600\cdot 10^3 Hz}=187.37 m$