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Wave Optics — Physics STD 12 Science — Question

Rajasthan BoardEnglish MediumSTD 12 SciencePhysicsWave Optics2 Marks
Question
The separation between the consecutive dark fringes in a Young's double slit experiment is $1.0\ mm.$ The screen is placed at a distance of $2.5m$ from the slits and the separation between the slits is $1.0\ mm.$ Calculate the wavelength of light used for the experiment.
✓

Answer

Given that, $\beta=1\text{mm}=10^{-3}\text{m}, $
$D = 2.5m$ and $d = 1\ mm = 10^{-3}m$
So, $10^{-3}\text{m}=\frac{25\times\lambda}{10^{-3}}$
$\Rightarrow\lambda=4\times10^{-7}\text{m}$
$=400\ \text{nm}.$

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