what does this experiment show
it is a two source superposition creating an interference pattern
why use last for this
monochromatic light therefore will all have the same wavelength so the diffraction will be the same and the light source is coherent
equation for young's double slit
wavelength = ax/dwhere a = slit separationx = fringe separation d = distance to wall
how to find 'a' from the diffraction grating
if 1000lines per cmdivide 1 cm by 1000 to find the slit separation
diffraction grating formula
nλ = dsinθwhere theta is the angle between the maxima and the zeroth order line n = the order of minima or maxima