Question

Calculate the wavelength, frequency and wave number of a light wave whose period is 2.0 x 10^-10 s.

Answer 1

Given, Time period T = 2.0 × 10⁻¹⁰s

Frequency v = \(\frac{1}{T}\) = \(\frac{1}{2.0\times10^{-10}}\) = 5 x 10⁹ Hz

wave length \(\lambda\) = \(\frac{c}{v}\) = \(\frac{3\times10^8m/s}{5\times10^9s^{-1}}\)

= 0.06 m

Wave number \((\bar v)\) = \(\frac{1}{\lambda}\)

= \(\frac{1}{0.06\,m}\)

= 16.67 m⁻¹