Describe how the wavelength of monochromatic light can be measured using a diffraction grating and a spectrometer.

Describe how the wavelength of monochromatic light can be measured using a diffraction grating and a spectrometer.

Describe how the wavelength of monochromatic light can be measured using a diffraction grating and a spectrometer.

Solution

Make the following adjustment

  • The collimator C is adjusted such that parallel rays emerge from it.
  • The telescope is adjusted so that parallel rays entering it are brought to a focus at the cross wire near its eyepiece.
  • The table is levelled so that the plane of P is parallel to the axis of rotation of the telescope.

  • The grating is placed on the table so that its plane is normal to incident light
  • The readings of the first diffraction image are observed on both sides of the normal at T1 and T2.
  • The angular difference is 2θ, and the wavelength is calculated from λ = d sin θ, where d is the spacing of the slits, obtained from the number of lines per centimeter of the grating.
  • If a second order image is obtained for a diffraction angle θ, then λ = d sin θ/2

Please subscribe by clicking the subscribe icon on the top right side this website to promote our website

Thank you so much.

CATEGORIES
TAGS
Share This

COMMENTS

Wordpress (0)
Disqus ( )