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NEET 2023 · Total Internal Reflection

Total Internal Reflection question from NEET 2023

Q20NEET 2023Easy

Total Internal Reflection

Light travels a distance xx in time t1t_1 in air and 10x10x in time t2t_2 in another denser medium. What is the critical angle for this medium?

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Answer: (c)

  1. Speed in air c=xt1c = \frac{x}{t_1}; speed in medium v=10xt2v = \frac{10x}{t_2}.
  2. sin⁡C=vc=10x/t2x/t1=10t1t2\sin C = \frac{v}{c} = \frac{10x/t_2}{x/t_1} = \frac{10t_1}{t_2}
  3. So the answer is (c) sin⁡−1(10t1t2)\sin^{-1}\left(\frac{10t_1}{t_2}\right).
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