Question

A glass slab of thickness 8 cm contains the same number of waves as 10 cm long path of water when both are traversed by the same monochromatic light. If the refractive index of water is $\frac{4}{3}$ , the refractive index of glass is

• A. $\frac{5}{3}$
• B. $\frac{5}{4}$
• C. $\frac{16}{15}$
• D. $\frac{3}{2}$

Answer 1

Answer: (A)

$\frac{5}{3}$

Answer 2

$_{a}{{n}_{w}}=\frac{4}{3}$ and $_{w}{{n}_{g}}=\left( \frac{10}{8} \right)$ $\therefore$ $_{a}{{n}_{g}}{{=}_{a}}{{n}_{w}}{{\times }_{w}}{{n}_{g}}$ $=\frac{4}{3}\times \frac{10}{8}=\left( \frac{5}{3} \right)$