Critical angle and total internal reflection

What is the critical angle for a light ray traveling in water with a refractive index of 1.33 that is incident on the surface of water above which there is ice with a refractive index of 1.31? Answer to the nearest degree.

• 80
• 70

• 60

• 50

The critical angle required for total internal reflection at a boundary between two substances is 30∘. The refractive index of the medium that which light is reflected is 1.1. What is the refractive index of the medium from which light propagates before it is reflected?

• 1.1
• 2.2

• 3.3

• 2.1

A light ray is entering a triangular prism, as shown in the figure below. The prism’s index of refraction is 1.7 a liquid whose index of refraction is 1.2 is placed on the prism’s surface. Which of the following is true about the incident angle on the 𝑥𝑦-face?

• It is less than the critical angle between the prism and the liquid

• It is 90∘.

• It is greater than the critical angle between the prism and the liquid.

• It is equal to the critical angle between the prism and the liquid.

Light travels a distance quantified by 3𝑥 metres in 5𝑡 seconds in air. If light travels a distance of 𝑥 metres in 𝑡 seconds in another medium, then the critical angle of this medium is ........... degrees.

• 53.13

• 59.04

• 36.87

• 30.96

A light ray falls with an incident angle of 59∘ on the boundary between two mediums of different densities. Knowing that 59∘ is the critical angle in this case and the refractive index of the denser medium is 1.75, what is the refractive index of the rarer medium?

• 1.5

• 1.67

• 1.33

• 1

A light beam travelling through air is incident on a transparent medium at an angle of 60∘.Part of the beam is reflected and the other part is refracted such that the reflected and refracted parts are perpendicular to each other. Calculate the critical angle for this medium with respect to air.

• 42.7∘

• 35.3∘

• 28.2∘

• 30.4∘

• A

• B

• C

• D

• 1.67

• 1.28

• 0.6

• 0.78

• 1.55

• 3.27

• 1.13

• 2.24

What is the largest angle of refraction for a light ray travelling from a glass of refractive index 1.6 into air?

• 63.2

• 90

• 29

• 38.6