Physics - Wave Optics Question with Solution | TestHub

In young's double slit experiment, the coherent sources are separated by a small distance and screen is placed at a large distance. Thin strips are placed in front of slits ${\mathrm{S}}_1$ and ${\mathrm{S}}_2$ as shown. The strip which is placed in front of $S_1$ has width 4 mm and has refractive index 1.5. The strip which is placed in front of ${\mathrm{S}}_2$ has a variable refractive index $\mu =1+\mathrm{Cx}$ where x is distance from left end of strip and $\mathrm{C}=1{\mathrm{mm}}^{-1}$. If central maxima is obtained at O (symmetrical with respect to slits), then find width of strip (in mm ) placed in front of ${\mathrm{S}}_2$.