Chapter 22 - Reflection and Refraction of Light - Learning Path Questions and Exercises - Exercises - Page 775: 28

$3.18cm$

We know that , $d=\frac{y\times sin(\theta_{1}-\theta_{2})}{cos\theta_{2}}$ By Snell's law, $1\times sin\theta_{1}=1.65\times sin\theta_{2}$, $\theta_{1}=40^{\circ}$ Solving for $\theta_{2}$, we have $\theta_{2}=23^{\circ}$ Hence, $d=10\times\frac{sin 17^{\circ}}{cos23^{\circ}}=3.18cm$