Question

A ray of light travelling in a medium of refractive index $\mu$ is incident at an angle $\theta$ on a composite transparent plate consisting of $50$ plates of $R.I$. $1.01\mu ,1.02\mu ,1.03\mu ,....,1.50\mu$ . The ray emerges from the composite plate into a medium of refractive index $1.6\mu$ at angle ${}^{\prime }{x}^{\prime }$. Then

• A. $sinx={\left(\frac{1.01}{1.5}\right)}^{50}sin\theta$
• B. $sinx=\frac{5}{8}sin\theta$
• C. $sinx=\frac{8}{5}sin\theta$
• D. $sinx={\left(\frac{1.5}{1.01}\right)}^{50}sin\theta$

Answer 1

Answer: (B)

According to Snell’s law,
$\mu sin\theta =1.6\mu sinx$
$\therefore sinx=\frac{5}{8}sin\theta$