Exam-style question
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Calculate the critical angle for a diamond with a refractive index of 2.42 when light travels from diamond to air.
- A.24.4°
- B.38.2°
- C.41.8°
- D.23.5°
Model answer
What a good answer should say
- 24.4°
Explanation
Why this works
The critical angle is calculated using the formula: critical angle = sin⁻¹(1/n). For diamond, n = 2.42.
Thus, sin⁻¹(1/2.42) = 24.4°. This angle represents the maximum angle of incidence for total internal reflection.
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