Critical angle and total internal reflection Quiz
Studying this course? Keep your progress in one place.
Pick an answer for each. Quizzes never use energy.
5 questions, one answer each
Each answer is checked as you go, with why.
See all 5 questions
1. What is the critical angle for light travelling from water (n = 1.33) to air?
- A. 41°
- B. 49°
- C. 53°
- D. 37°
2. A transparent material has a critical angle of 30° in air. What is its refractive index?
- A. 0.50
- B. 1.15
- C. 1.5
- D. 2.0
3. Which situation can lead to total internal reflection?
- A. Light in glass meeting a glass–air boundary at an angle above the critical angle
- B. Light in air meeting an air–glass boundary at a large angle
- C. Light in glass meeting a glass–air boundary at an angle below the critical angle
- D. Light in air meeting an air–water boundary at 90°
4. A ray in glass of refractive index 1.50 meets a glass–air boundary at 40°. What happens?
- A. It is totally internally reflected, as 40° is above the critical angle
- B. It is totally internally reflected, as 40° is below the critical angle
- C. Some light refracts into the air, as 40° is below the critical angle of 42°
- D. It is refracted along the boundary
5. A ray in water (critical angle 49°) meets the surface at 60°. What does it do?
- A. Refracts into the air at 60°
- B. It is totally internally reflected, as 60° exceeds 49°
- C. It travels along the surface
- D. It is totally internally reflected, as 60° is below 49°