 The phenomenon illustrated in the figure occurs when a light ray:
Atravels from a rarer medium to a denser medium at any angle
Btravels from a denser medium to a rarer medium at any angle
Ctravels from a denser medium to a rarer medium at an angle greater than the critical angle
Dtravels from a rarer medium to a denser medium at an angle greater than the critical angle
Answer & Solution
Correct answer: C. travels from a denser medium to a rarer medium at an angle greater than the critical angle
**Total Internal Reflection (TIR)** requires two conditions to fire simultaneously:
1. Light is going from the **denser to rarer** medium (e.g. water → air).
2. The angle of incidence **exceeds the critical angle** $C$, where $\sin C = 1/\mu$.
If either condition fails the ray refracts (option B), or refraction never even arose (options A and D — going *into* a denser medium can never give TIR, the ray always refracts inward).
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