Question

A ray of light passes normally through a slab $(\mu =1.5)$ of thickness ${}^{\prime }{t}^{\prime }$. If the speed of light in vacuum be ${}^{\prime }{c}^{\prime }$ then time taken by the ray to go across the slap will be

• A. $\frac{t}{c}$
• B. $\frac{3t}{2c}$
• C. $\frac{2t}{3c}$
• D. $\frac{4t}{9c}$

Answer 1

The correct option is B $\frac{3t}{2c}$

$\begin{array}{c}\eta =\frac{c}{v}\\ \Rightarrow v=\frac{c}{1.5}=\frac{2c}{3}\\ time=\frac{3t}{2c}\\ Hence,\\ optionBiscorrectanswer.\end{array}$