A double-slit interference experiment is performed in the air. Later, the same apparatus is immersed in benzene (index of refraction, n = 1.50), and the experiment is repeated. When the apparatus is in benzene, you observe the interference fringes to be
A) more closely spaced as when the apparatus is in air.
B) equally spaced as when the apparatus is in air.
C) more widely spaced as when the apparatus is in air.
D) Impossible to tell without knowing the wavelength of light in use.
E) Impossible to tell without knowing the separation between the slits.

Question

Quizplus · Accepted Answer

The interference fringe spacing is inversely proportional to the index of refraction. In benzene, the effective wavelength of light is shorter due to the higher index of refraction, leading to more closely spaced fringes compared to air.

A Double-Slit Interference Experiment Is Performed in the Air