Calculate the wavelength, frequency and wave number of a light wave whose period is 2.0 × 10–10 s.

Given:

Period, T = 2.0 × 10–10 s


Frequency, v = [1] / T


= [1] / [2.0 × 10–10]


= 5.0 × 109 Hz


We know the following basic relation,


Speed of Light = [Frequency] × [Wavelength]


We know speed of light = 3×108 m/s


Wavelength, λ = [3×108] / [5.0 × 109]


= 0.06 m


Wave Number = [1] / [λ]


= [1/0.06]


= 16. 667 m-1


Therefore, the frequency of wave is 5.0 × 109 Hz and its wavelength is 0.06 m and its wave number 16. 667 m-1


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