Diffraction Gratings Worksheet
1. How many principal maxima are produced when a grating with a spacing of 2.00 x 10 -6 m is illuminated
normally with light of wavelength 6.44 x 10-7 m?
2. Light of wavelength 5.70 x 10-7 m is incident normally on a grating with a spacing of 2.00 x 10-6 m. What is
the angle to the normal of: (a) a first order principal maximum, and (b) a second order principal maximum?
3. A diffraction grating produces a second order principal maximum at 50.6˚ to the normal when being
illuminated normally with light of wavelength 644 nm. Calculate the number of lines per millimetre of the
grating.
4. Monochromatic light of wavelength 600 nm is incident normally on an optical transmission grating of
spacing 2.00 μm. Calculate the maximum possible order and the angular positions of the maxima.
5. Light consisting of wavelengths 420 nm and 650 nm is incident normally on a transmission grating of 6.00 x
105 lines m-1. Calculate the separation of the wavelengths in the second order spectrum.
6. What is the wavelength of light which gives a first order maximum at an angle of 22˚30’ when incident
normally on a grating with 600 lines mm-1.
7. Light of wavelength 500 nm is incident normally on a diffraction grating of width 15.0 mm, on which 10.0 x
103 lines have been ruled. Calculate the angular positions of the various orders.
8. When a certain grating is illuminated normally by monochromatic light of wavelength 600 nm, the first order
maximum is observed at an angle of 21.1˚. If the same grating is now illuminated with light with wavelength
from 500 nm to 700 nm, find the angular spread of the first order spectrum.
Diffraction Gratings Worksheet
1. How many principal maxima are produced when a grating with a spacing of 2.00 x 10 -6 m is illuminated
normally with light of wavelength 6.44 x 10-7 m?
2. Light of wavelength 5.70 x 10-7 m is incident normally on a grating with a spacing of 2.00 x 10 -6 m. What is
the angle to the normal of: (a) a first order principal maximum, and (b) a second order principal maximum?
3. A diffraction grating produces a second order principal maximum at 50.6˚ to the normal when being
illuminated normally with light of wavelength 644 nm. Calculate the number of lines per millimetre of the
grating.
4. Monochromatic light of wavelength 600 nm is incident normally on an optical transmission grating of
spacing 2.00 μm. Calculate the maximum possible order and the angular positions of the maxima.
5. Light consisting of wavelengths 420 nm and 650 nm is incident normally on a transmission grating of 6.00 x
105 lines m-1. Calculate the separation of the wavelengths in the second order spectrum.
6. What is the wavelength of light which gives a first order maximum at an angle of 22˚30’ when incident
normally on a grating with 600 lines mm-1.
7. Light of wavelength 600 nm is incident normally on a diffraction grating of width 20.0 mm, on which 10.0 x
103 m lines have been ruled. Calculate the angular positions of the various orders.
8. When a certain grating is illuminated normally by monochromatic light of wavelength 600 nm, the first order
maximum is observed at an angle of 21.1˚. If the same grating is now illuminated with light with wavelength
from 500 nm to 700 nm, find the angular spread of the first order spectrum.