1. The light with the wavelength 500nm propagates through the medium with index of refraction 2.5. Find the speed and the frequency of the light in the medium.
2. A diffraction grating is illuminated with light if wavelength 500nm. It produces the first minimum at 45 degree. Find the number of lines(slits) per mm of diffraction grating.
3. A double spit experiment is performed with light of wavelength 600nm. A very wide viewing screen is 2 m behind the grating. What is the distance between the two m=2 bright fringes on the screen? The slit separation is 0.1 mm.