Question 335: Wave Optics

Question

In biprism experiment, if $$5^{	ext {th }}$$ bright band with wavelength $$\lambda_1^{\prime}$$ coincides with $$6^{	ext {th }}$$ dark band with wavelength $$\lambda_2{ }^{\prime}$$ then the ratio $$\left(\frac{\lambda_2}{\lambda_1}ight)$$ is

Accepted Answer

The fifth bright band will be:
$$\mathrm{y}_5=\frac{5 \lambda_1 \mathrm{D}}{\mathrm{d}}$$
$$	herefore \quad$$ The sixth dark band will be:
$$\begin{aligned}
& \mathrm{y}_6{ }^{\prime}=\frac{11 \lambda_2 \mathrm{D}}{2 \mathrm{~d}} \
& 	ext { Given: } \mathrm{y}_5=\mathrm{y}_6^{\prime} \
& 	herefore \quad \frac{5 \lambda_1 \mathrm{D}}{\mathrm{d}}=\frac{11 \lambda_2 \mathrm{D}}{2 \mathrm{~d}} \
& 5 \lambda_1= \frac{11 \lambda_2}{2} \
& \frac{\lambda_2}{\lambda_1}=\frac{10}{11}
\end{aligned}$$

Answer

$$\frac{9}{7}$$

Answer

$$\frac{7}{9}$$

Answer

$$\frac{10}{11}$$

Answer

$$\frac{11}{10}$$

Wave Optics

In biprism experiment, if $5^{\text {th }} bright band with wavelength \lambda_1^{\prime} coincides with 6^{\text {th }} dark band with wavelength \lambda_2{ }^{\prime} then the ratio \left(\frac{\lambda_2}{\lambda_1}\right)$ is

Choose the correct answer: