(i) Describe the pattern produced on a screen by a red laser beam incident on a diffraction grating.

(ii) Laser light of wavelength 632 nm is incident on a diffraction grating having 600 lines per mm. Determine the angular separation between the first and second order maxima.

(i) equally spaced;
(red) spots/maxima/bright fringes;
and wide minima/dark fringes;

(ii) use of diffraction grating equation;
correct use of number of lines per mm or calculation of grating spacing;
one angle correctly calculated (angles are 22.3° and 49.3°);
27°;