Question

As shown in the figure, in Young's double slit experiment, a thin plate of thickness $t=10 \mu m$ and refractive index $\mu=12$ is inserted infront of slit $S_1$ The experiment is conducted in air $(\mu-1)$ and uses a monochromatic light of wavelength $\lambda=500 nm$ Due to the insertion of the plate, central maxima is shifted by a distance of $x \beta_0 \beta_0$ is the fringe-width befor the insertion of the plate The value of the $x$ is ___

Answer 1

The correct answer is 4.
Fringe shift x=λt(μ−1)​B
=5×10−710×10−6(1.2−1)​B
=5×10−710−5×0.2​=4