Question 66 of 191
Two light waves of wavelengths and are used in Young's double slit experiment to obtain interference fringes on a screen placed away from plane of slits. If the two slits are separated by , then shortest distance from the central bright maximum to the point where the bright fringes of the two wavelength coincide will be ______ .
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Answer: 48
Fringe width for both cases can be written as.{\omega }_{1}=\dfrac{{\lambda }_{1}D}{d}&{\omega }_{2}=\dfrac{{\lambda }_{2}D}{d}.
Using values of wavelength, we get {\omega }_{1}=16mm&{\omega }_{2}=12mm.
Let y be the common distance of the bright fringes by the both wavelength, then
.
As LCM , therefore at distance both bright fringes will be found.
Using values of wavelength, we get {\omega }_{1}=16mm&{\omega }_{2}=12mm.
Let y be the common distance of the bright fringes by the both wavelength, then
.
As LCM , therefore at distance both bright fringes will be found.