Find the widths of a slit and a central peak in a single slit diffraction.

1. While red light of wavelength 620 nm falls on a single slit, it creates a central diffraction maximum that is 8.80 mm wide on a screen 2 m away. How wide is the slit? How wide will the central peak be if the red light is replaced with a blue light of wavelength 500 nm?

2. The sodium D line is a doublet consisting of 2 wavelengths, 588.90 and 589.592 nm. find out the angular separation between these two lines in the first-order spectrum for a grating with 4000 lines per centimeter. Replicate for the second order.