What is the highest order spectrum which may be seen with monochromatic light of wavelength 600 nm by means of a diffraction grating with 5000 lines/cm ?

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Answer 1 · 2018-05-01T11:59:19

The highest order is #=3#

The equation for the diffraction is

#n lambda= dsintheta#

The wavelength of the light is #lambda=600*10^-9m#

The width of a line is #d=1/(5000*100)m#

The maximum value for #sintheta=1#

Therefore,

#n=(dsintheta)/(lambda)=(0.2*10^-5)/(6*10^-7)=0.033*10^2=3.33≃3#

The highest order is #=3#