In biprism experiment, $6^{ ext {th }}$ bright band with wavelength ' $\lambda_1$ ' coincides with $7^{ ext {th }}$ dark band with wavelength ' $\lambda_2$ ' then the ratio $\lambda_1: \lambda_2$ is (other setting remains the same)

Question

In biprism experiment, $6^{	ext {th }}$ bright band with wavelength ' $\lambda_1$ ' coincides with $7^{	ext {th }}$ dark band with wavelength ' $\lambda_2$ ' then the ratio $\lambda_1: \lambda_2$ is (other setting remains the same)

Aicharya · Accepted Answer

$\begin{aligned} & 	ext { Distance of } 6^{	ext {th }} 	ext { bright band }=\frac{6 \lambda_1 D}{d} \ & 	ext { Distance of } 7^{	ext {th }} 	ext { dark band }=\frac{6.5 \lambda_2 D}{d} \ & 	herefore \frac{6 \lambda_1 D}{d}=\frac{6.5 \lambda_2 D}{d} \ & 	herefore \frac{\lambda_1}{\lambda_2}=\frac{6.5}{6}=\frac{13}{12}\end{aligned}$

In biprism experiment, $6^{\text {th }}$ bright band with wavelength ' $\lambda_1$ ' coincides with…

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