When monochromatic light passes through the interface between two unknown materials at an angle θ where 0∘<θ<90∘, no changes in the direction of propagation of light are observed. What can be said about the two materials?

The question is incomplete, the options in the question are:

The two materials have matching indexes of refraction.

The second material through which light propagates has a lower index of refraction.

The second material through which light propagates has a higher index of refraction.

The two materials are identical

The two materials have matching indexes of refraction.

Explanation:

The phenomenon of refraction reveals that, when light propagates through the interface between two materials with different indexes of refraction, the direction of propagation of light changes. When this does not happen, it means that the two materials have very similar refractive indexes. For instance, the refractive index of glass Pyrex is 1.474 and that of glycerin is 1.473 hence no relevant change in the direction of propagation of light can be observed when light passes between the interface of the two substances. That does not mean that they are both the same material or identical materials.

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