Physics - Wave Optics Question with Solution | TestHub

$n_1{\overline{X}}_1=n_2{\overline{X}}_2$

$n_1\frac{D{\text{λ}}_1}{d}=n_2\frac{D{\text{λ}}_2}{d}$

$n_1{\text{λ}}_1=n_1{\text{λ}}_2$

$\frac{{\text{λ}}_1}{{\text{λ}}_2}=\frac{n_2}{n_1}=\frac{\text{4000}}{\text{5600}}=\frac{\text{40}}{\text{58}}=\frac{\text{5}}{7}$

$\therefore \frac{n_2}{n_1}=\frac{5}{7}\Rightarrow \frac{X_1}{X_2}=\frac{7}{5}$

$\therefore y=7{\overline{X}}_1=\frac{7D{\text{λ}}_1}{d}$