Velocity of light in glass whose refractive index with respect to air is 1.5 is `2 xx10^(8) m//s` and in certain liquid the velocity of light found to be `2.5 xx10^(8)` m/s . The refractive index of the liquid with respect to air is

Options

A. 0.64
B. 0.8
C. 1.2
D. 1.44

Answer

C

Explanation

`._(a)mu_(g) = (v_(a))/(v_(g))`
Thus, `v_(a) = ._(a)mu_(g) xx v_(g)`
`= 1.5 xx 2 xx 10^(8) = 3 xx 10^(8) m//s`
`._(a)mu_(1) = (v_(a))/(v_(i)) = (3 xx 10^(8))/(2.5 xx 10^(8)) = 1.2`