Diffraction and diffraction gratingsAQA A-Level Physics: Mind map

Exam questions on Diffraction and diffraction gratings

1. Monochromatic light of wavelength 600 nm is directed at a single narrow slit of width 0.10 mm. The light that passes through forms a diffraction pattern on a screen several metres away.
   The slit is replaced by a gap 10 mm wide. Explain why little diffraction is now seen.2 marks
2. Light of wavelength 589 nm from a sodium lamp is incident normally on a diffraction grating that has 600 lines per millimetre.
   Calculate the angle between the straight-through direction and the first-order maximum.2 marks
3. A laser of unknown wavelength is directed at normal incidence at a diffraction grating that has 300 lines per millimetre. The second-order maximum is observed at an angle of 22.3° to the straight-through direction.
   Calculate the wavelength of the laser light.3 marks