Correct Answer - Option 1 : 1.414
In case of refraction, deviation angle from rarer medium to denser medium, \(\delta = i - r\)
Here δ = 15o and i = 45o
\(r = 45^\circ - 15^\circ = 30^\circ\)
So the refractive index of liquid as compared to air,
\(\mu = \frac{{\sin i}}{{\sin r}} = \frac{{\sin 45^\circ }}{{\sin 30^\circ }} = \sqrt 2 = 1.414\)