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STD 12 - 9. Ray optics abd optical instruments — JEE STD 11 Science — Question

Gujarat BoardEnglish MediumSTD 11 ScienceJEESTD 12 - 9. Ray optics abd optical instruments4 Marks
MCQ
A ray of light travelling in a transparent medium falls on a surface separating the medium from air at an angle of incidence of $45^o $. The ray undergoes total internal reflection. If n is the refractive index of the medium with respect to air, select the possible value ($s$) of n from the following
  • A
    $1.3$
  • B
    $1.6$
  • C
    $1.5$
  • ✓
    Both $(b)$ and $(c)$
✓

Answer

Correct option: D.
Both $(b)$ and $(c)$
d
( d) For $TIR\,\, i > C$
==> $sin i > sin C$ ==> $\sin 45^\circ > \frac{1}{n}$==> $n > \sqrt 2 $ ==> $n > 1.4$

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