illuminated by normally incident light of wavelength 
for: a diffraction grating with slits separated by a distance illuminated by normally incident light of wavelength
relates: the angles 
at which 
order maxima in the diffraction pattern will be found, to 
and 
[P6.1, P8.2]
states: that 
[P6.1, P8.2]
Copyright 1997, The Open University