Question 340: Wave Optics

Question

In Young's double slit experiment the separation between the slits is doubled without changing other setting of the experiment to obtain same fringe width, the distance 'D' of the screen from slit should be made

Accepted Answer

Fringe width,
$$\mathrm{W}=\frac{\lambda \mathrm{D}}{\mathrm{d}}$$
Given: $$\mathrm{d}=2 \mathrm{~d}$$
$$\Rightarrow \mathrm{W}^{\prime}=\frac{\lambda \mathrm{D}^{\prime}}{2 \mathrm{~d}}$$
Since given,
$$\mathrm{W}=\mathrm{W}^{\prime}$$
$$\begin{aligned}
& 	herefore \quad \frac{\lambda \mathrm{D}}{\mathrm{d}}=\frac{\lambda \mathrm{D}^{\prime}}{2 \mathrm{~d}} \
& 	herefore \quad \mathrm{D}^{\prime}=2 \mathrm{D}
\end{aligned}$$

Answer

$$\frac{\mathrm{D}}{2}$$

Answer

$$\frac{\mathrm{D}}{\sqrt{2}}$$

Answer

$$2 \mathrm{D}$$

Answer

$$4 \mathrm{D}$$

Wave Optics

In Young's double slit experiment the separation between the slits is doubled without changing other setting of the experiment to obtain same fringe width, the distance 'D' of the screen from slit should be made

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