Exam-style question
Try this first
If the critical angle for a material is 42 degrees, what happens when light hits the boundary at 50 degrees?.
- A.Light is refracted into the second medium.
- B.Light is totally internally reflected.
- C.Light is absorbed by the boundary.
- D.Light continues straight without change.
Model answer
What a good answer should say
- Light is totally internally reflected.
Explanation
Why this works
When the angle of incidence (50 degrees) exceeds the critical angle (42 degrees), total internal reflection occurs, meaning the light does not enter the second medium but is reflected back into the first medium.
Common mistake
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