An air wedge is formed using two glass plates that are in contact along their left edge.When viewed by highly monochromatic light, there are exactly 4001 dark bands in the reflected light.The air is now evacuated (with the glass plates remaining rigidly fixed)and the number of dark bands decreases to exactly 4000.The index of refraction of the air is:
A)0.00025
B)0.00050
C)1.00025
D)1.00050
E)1.00000, by definition

Question

Quizplus · Accepted Answer

The change in the number of dark bands is due to the change in the optical path length caused by the removal of air. The index of refraction of air is slightly greater than 1, and the decrease in dark bands from 4001 to 4000 indicates that the index of refraction of air is approximately 1.00025.

An Air Wedge Is Formed Using Two Glass Plates That