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Thursday, 02 April 2026
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A ray of light traveling from a rectangular glass block of refractive index 1.5 into ...

A ray of light traveling from a rectangular glass block of refractive index 1.5 into air strikes the block at an angle of incidence of 30. Calculate its angle of refraction.
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  • A 48.6°
  • B 19.5°
  • C 20.0
  • D 45.0
Correct Answer: Option B
Explanation:
n = \(\frac{sin I}{sin r} = \frac{sin 30^o}{sin r}\)
1.5 = \(\frac{\sin 30^o}{sin r}\)
1.5 sin r = \(\frac{\sin 30^o}{1.5} = \frac{0.5}{1.5}\)
sin r = 0.3333
= 19.47\(^o\)

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