Compute the all parts of given question:
A Michelson's interferometer is illuminated by krypton orange light, which has a wavelength of 605.8 nm. The interferometer is adjusted to give circular fringes (i.e. fringes of constant inclination), and the distances between the beam splitter and the two mirrors are adjusted so that the central spot is a maximum of intensity. The difference between these distances is approximately 1.5 mm.
Part I: Calculate the angular radii of the first three bright fringes
Part II: A cross hair is positioned on the third fringe, and one of the mirrors is moved. During the movement, 500 fringes pass the cross hair. How far was the mirror moved?
Please explain each step and equations used.