In a Michelson interferometer, light of wavelength 632.8 nm from a He-Ne laser is used. When one of the mirrors is moved by a distance , 8 fringes move past the field of view. What is the value of the distance ?
An experimenter detects 251 fringes when the movable mirror in a Michelson interferometer is displaced. The light source used is a sodium lamp, which emits light with a characteristic wavelength of 589 nm. By what distance did the movable mirror move?