A ray of light travels from air to glass at an angle of incidence of ${37}^{\circ }$, the angle of refraction is ${24}^{\circ }$. What is the refractive index of glass?
(Given: $\sin {37}^{\circ }=0.60,\sin {24}^{\circ }=0.40)$

The correct option is B $1.5$
Snell's law states that ratio of sine of angle of incidence to sine of angle of refraction is a constant. This constant is called the refractive index of the medium. Hence:
$n_{ga}=\frac{\sin r}{\sin r}=\frac{\sin {37}^{\circ }}{\sin {24}^{\circ }}$
$=\frac{0.60}{0.40}=1.5$