Task id17222

Cylindrical tubes, each 10 cm long, closed at the ends with transparent plane-parallel plates, were placed in both light beams of the Michelson interferometer. First, air was pumped out of the tubes, then hydrogen was introduced into one of them, and the interference pattern shifted by 47.5 fringes. What is the refractive index of hydrogen? The experiment was carried out in light with a wavelength of 590 nm.