How is the wavelength of monochromatic light measured

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The wavelength of monochromatic light can be measured using a diffraction grating and a spectrometer. When a parallel beam of light hits the grating at normal incidence, the relationship dsinθ = nλ is used to determine the wavelength, where d is the grating spacing, θ is the angle of diffraction, and n is the order of the diffracted beam. A spectrometer enhances measurement accuracy by incorporating a collimator for the incident beam, a rotating table for the grating, and a telescope for focusing the emergent beams. The spectrometer also features a vernier scale for precise angle measurements. This method effectively allows for accurate wavelength determination of monochromatic light.
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how is the wavelength of monochromatic light measured by using diffraction grating and spectometer?
 
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What have you found out so far?
 


Using diffraction grating, when incident parallel beam is at normal incidence, then emergent parallel beams are seen in directions such that
dsinθ = nλ

by considering the spacing of grating, and the order of the diffracted beams as well as the angle of diffracted beams to the normal, the wavelength may be measured.

Is it Correct?

What about spectrometer?
 


Hello franklinear,yes it is correct.A spectrometer is an optical instrument that can be used to make measurements of the type you described with a high degree of accuracy.There is a collimator which can be adjusted to produce the parallel incident beam,a table on which to place the grating and a telescope which can be adjusted to focus the emergent beams.The table and telescope can be rotated and and there is a vernier scale to measure the angles.
 
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