C. Diffraction Grating Devise an experiment to measure the wavelength of the laser light using a diffraction grating. You will need a diffraction grating or CD DVD for this part. Note that in the equation, the only unknown variable is A while the other variables are known or measurable. Remember that the equation gives the positions of the maxima and that d is the spacing between grating lines (specification is given as member of lines per unit distance). On Busch, use the grading slide labeled either B (300 lines/mm) or C (600 limes/mm) . On Douglass, the mounted grating you will use has a line density of 400