Calculate the wavelength, frequency and wave number of a light wave whose period is 2.0 × 10–10 s.
Given period = 2.0 x 10-10s
We know, Frequency (ν) of light 
,therefore putting the values .we get
We also know 
Where,c = velocity of light in vacuum = 3×108 m/s
Substituting the value in the given expression of λ, we get
Wave number 
of light 
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