
Why diffraction grating is preferred over double-slit experiment?

Important Questions on Optics
(b) This diagram shows the experimental setup (left) used to analyse the spectrum of a sodium discharge lamp with a diffraction grating with lines , and the spectral lines observed (right) in the developed photographic film.
(ii) Describe two differences between these two spectra.



(b) This diagram shows the experimental setup (left) used to analyse the spectrum of a sodium discharge lamp with a diffraction grating with lines , and the spectral lines observed (right) in the developed photographic film.
(i) Explain why two spectra are observed.



White light is incident normally on a diffraction grating with a slit-separation of . The visible spectrum has wavelengths between and .
(a) Calculate the angle between the red and violet ends of the first-order spectrum.



The spectrum of sodium includes two lines at wavelength and . A sodium lamp is viewed by a diffraction grating that just manages to resolve these two lines in the third-order at . Determine
a. The slit spacing of the grating.



A grating with is illuminating with the light of wavelength .
a. Determine the angles at which maxima are observed.

One of the spectral lines from a hydrogen discharge lamp has wavelength . This light is incident normally at a diffraction grating with lines .
Calculate the angles for the first- and second-order maxima for this light





A grating with is illuminating with the light of wavelength .
b. Determine the largest order that can be seen with which this grating and this wavelength.


