55. The apparatus for the observation of Newton's rings space between the lens and the glass plate is filled with liquid. To determine the refractive index of the liquid, if the diameter of the second ring of light in the reflected light is equal to 5 mm. Light with a wavelength of 0.615 microns is normally incident. The radius of curvature of the lens 9 m.

Detailed solution. Decorated in Microsoft Word 2003. (Target decided to use formula editor)