A glass slab of thickness 4 cm contains the same number of waves as 5 cm of water when both are trav

Question

A glass slab of thickness 4 cm contains the same number of waves as 5 cm of water when both are traversed by the same monochromatic light. If $\mu$ of water is $\frac{4}{3}$ the $\mu$ of glass is\

Professor PC Thomas Classes · Answer

$\lambda_{g}=\frac{4}{N}$\ $\lambda_{\omega}=\frac{5}{\mathrm{~N}}$\ $\mathrm{n}_{\mathrm{g}}=\frac{\mathrm{C}_{\mathrm{a}}}{\mathrm{C}_{\mathrm{g}}}$\ 4 cm glass\ $\mathrm{n}_{\omega}=\frac{\mathrm{C}_{\mathrm{a}}}{\mathrm{C}_{\omega}}$\ N waves\ $\frac{\mathrm{n}_{\mathrm{g}}}{\mathrm{n}_{\omega}}=\frac{\mathrm{C}_{\omega}}{\mathrm{C}_{\mathrm{g}}}$\ 5 cm water\ N waves $$ \begin{aligned} & =\frac{\mathrm{f} \lambda_{\omega}}{\mathrm{f} \lambda_{\mathrm{g}}} \ & =\frac{\lambda_{\omega}}{\lambda_{\mathrm{g}}}=\frac{5}{4} \ \mathrm{n}_{\mathrm{g}} & =\mathrm{n}_{\omega} 	imes \frac{5}{4}=\frac{4}{3} 	imes \frac{5}{4}=\frac{5}{3} \end{aligned} $$