Which one is true about the slit separation, a, the distance D from the slits to the screen and the separation of the fringes, x, in a Young's two slit experiment?

The figure shows a monochromatic light of wavelength  $\lambda$  being incident onto a single slit. The slit size is a. What is the value of d in terms of  $\lambda$  ?

If  $n_1$   $<$   $n_2$  , what is the optical path difference between the two reflected rays?

You observe two very closely-spaced sources of white light through a circular opening using various filters. Which color filter is most likely in resolving the images on your retinas as coming from two distinct sources?

A diffraction grating that has 2000 slits per centimetre is used to measure the wavelengths emitted by hydrogen gas. At what angle in the first order spectrum would you expect to find the violet line that has a wavelength of 434 nm?

A diffraction grating that has 4000 lines per centimetres is illuminated at normal incidence with white light ( wavelength range of 400 nm to 700 nm). How many orders of spectra can one observe in the transmitted light?

Green light of wavelength 500 nm is incident normally on a grating, and the second order is diffracted  $32.0\degree$  from the normal. How many lines per cm are marked on the grating?