Question

The wave number of a beam of light is 800cm-1. What is the wavelength of light in nanometers? Also find out frequency of light.

Answer 1

$$\begin{gathered} Wavenumber,\overline{v}=1/wavelength\left(\lambda \right) \\ \lambda =1/\overline{v} \\ =1/800c{m}^{-1} \\ =0.00125cm \\ =12500nm(1cm={10}^{7}nm) \end{gathered}$$

And

$$\begin{gathered} Frequency,\nu =c\overline{v} \\ =3x{10}^{8}m/sx800c{m}^{-1} \\ =3x{10}^{10}cm/sx800c{m}^{-1} \\ =2.4x{10}^{13}{s}^{-1} \end{gathered}$$