Question

An experimenter detects 251 fringes when the movable mirror in a Michelson interferometer is displaced. The light source used is a sodium lamp, wavelength 589 nm. By what distance did the movable mirror move?

Answer 1

The movable mirror in the Michelson interferometer moved approximately 73.9295 μm.

Step-by-step explanation:

A Michelson interferometer is a device used to measure the interference of light waves. In this case, the experimenter detected 251 fringes when the movable mirror was displaced. The light source used was a sodium lamp with a wavelength of 589 nm. To calculate the distance the movable mirror moved, we can use the formula:

Distance = (Number of fringes * Wavelength) / 2

Plugging in the values, we have:
Distance = (251 * 589 nm) / 2 = 73929.5 nm = 73.9295 μm

So, the movable mirror moved approximately 73.9295 μm.