Question

A certain electromagnetic wave has a wavelength of$625nm$. What is the frequency of the wave?

Answer 1

Step 1: Given data

The wavelength of electromagnetic wave$=625nm$

Convert $nmtom$

$1nm={10}^{-9}m$

$\Rightarrow 625nm=625\times {10}^{-9}m$

Step 2: Calculation:

Formula used: $speed\left(c\right)=wavelength\left(\lambda \right)\times frequency\left(f\right)$

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

where$c$ is the speed of light = $3\times {10}^{8}m/s$

$f$ is frequency

$\lambda$ is wavelength

$$\begin{gathered} \Rightarrow f=\frac{3\times {10}^8}{625\times {10}^{-9}} \\ \Rightarrow f=4.80\times {10}^{14}Hz \end{gathered}$$

Hence the frequency of the wave is $4.80\times {10}^{14}Hz$