Directions : In the following question more than one of the answers given may be correct. Select the correct answer and mark it according to the code:
A ray of light travelling in a transparent medium falls on a surface separating the medium from air, at an angle of incidence of\[45{}^\circ \]. The ray undergoes total internal reflection. If |li is the refractive index of the medium with respect to air, select the possible values of [i from the following (1) 1.3 (2) 1.5 (3) 1.4 (4) 1.6A) 1, 2 and 3 are correct
B) 1 and 2 are correct
C) 2 and 4 are correct
D) 1 and 3 are correct
Correct Answer: C
Solution :
Let the angle of incidence is i and critical angle is C. For total internal reflection \[\sin i>\sin C\] But \[\sin C=\frac{1}{\mu }\] \[\therefore \] \[\sin i>\frac{1}{\mu }\] \[\mu >\frac{1}{\sin i}\] \[\mu >\frac{1}{\sin {{45}^{o}}}\] \[\mu >\sqrt{2}\] \[\mu >1.414\] Hence, option is correct.
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