Path of ray of light passing through three liquids of refractive indices `mu_1,mu_2,mu_3` is as shown in Fig. Which liquid has the smallest index of refraction ?
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Explanation

As is clear from Fig., in going from liquid `A` to liquid `B`, the ray of light bends away from normal. Therefore, `mu_2 lt mu_1`.
Again, in going from liquid `B` to liquid `C`, the ray of light bends towards normal. Therefore, `mu_2 lt mu_3`.
Hence the smallest index of refraction is `mu_2`.
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