2. (a) For a diffraction grating, explain the advantage of i. many slits, 11. closely spaced slits (b) A diffraction gra
Posted: Sat Jul 02, 2022 7:03 pm
2. (a) For a diffraction grating, explain the advantage of i. many slits, 11. closely spaced slits (b) A diffraction grating has 7,000 lines per centimeter. When the grating is illuminated normally with a monochromatic light, the second order spectral line is found at 62°. Find (5 marks) i. wavelength of the light ii. third order maximum (3 marks) (c) Red laser light from a He-Ne laser (= 632.8 nm) is used to calibrate a diffraction grating. If this light creates a second-order fringe at 53.20 after passing through the grating, and light of an unknown wavelength λ creates a first-order fringe at 20.6°, Find 2. (2.5 marks)