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a.) A light beam goes from a medium with index of refraction 1.6 into another me

ID: 1775162 • Letter: A

Question

a.) A light beam goes from a medium with index of refraction 1.6 into another medium with index of refraction 3.5. Inside the new medium, which of the following is true?

The frequency becomes higher.

The wavelength becomes longer.

The wavelength stays the same.

The light beam moves with the same velocity.

The wavelength becomes shorter. (TRUE)

Tries 2/2

b.) What is the critical angle of total internal reflection?

16.6°

27.2°

38.7°

None of the above.

Tries 0/2

c.) What is the critical angle of total internal reflection if the beam direction is reversed, i.e., if the beam goes from the medium with index of refraction 3.5 into the medium with index of refraction 1.6?

16.6°

27.2°

38.7°

None of the above.

Tries 0/2

Explanation / Answer

A) As light travels from a less dense medium to a more dense medium (like from air to glass), its velocity decreases, so the wavelength increases

Total Internal Reflection only takes place when both of the following two conditions are met:

B) None of the above (TIR not possible)

C) sine(crit) = nr/ni = 1.6/3.5

crit = 27.2°