Question

Electromagnetic radiation having a \(15.0\mu m\)wavelength is classified as infrared radiation. What is its frequency?

Short answer

The frequency of the electromagnetic radiationis \(20{\rm{ }}GHz\).

Step-by-step solution

Definition of frequency 

Frequency is the number of waves that pass through a specific spot in a specific length of time.

Given information and Formula to be used

The wavelength of electromagnetic radiation: \(\lambda = 15\mu m = 15 \times {10^{ - 6}}\;m\)

The speed of light value is: \(c = 3 \times {10^8}\;m/s\)

For any electromagnetic wave, the relationship between propagation speed, wavelength, and frequency is given by,

\(c = f\lambda \)

Calculate the frequency

Consider the given formula and simplify,

We have

\(\begin{array}{c}c = f\lambda \\3 \times {10^8} = f \times 15 \times {10^{ - 6}}\\f = 20{\rm{ }}GHz\end{array}\)

Therefore, frequency is \(20{\rm{ }}GHz\).