In a Young's double slit experiment,light from a laser source falls on a pair of very narrow slits separated by $1.0 \,\mu m$ and bright fringes separated by $1.0 \,mm$ are observed on a distant screen. If the frequency of the laser light is doubled,the separation of the bright fringes is .......$\,mm$?

In Young's double-slit experiment,a monochromatic light source is used to illuminate slits $S_1$ and $S_2$. An interference pattern is obtained on the screen with a fringe width of $w$. If a mica sheet of thickness $t$ and refractive index $\mu$ is placed in front of one of the slits,the new fringe width $w'$ becomes:

Two wavelengths $\lambda_1 = 450 \ nm$ and $\lambda_2 = 650 \ nm$ are used in Young's double slit experiment. The minimum order of fringe produced by $\lambda_2$ which overlaps with a fringe produced by $\lambda_1$ is $n$. The value of $n$ is . . . . . . .

In an interference arrangement similar to Young's double slit experiment,the slits $S_1$ and $S_2$ are illuminated with coherent microwave sources each of frequency $10^6 \ Hz$. The sources are synchronized to have zero phase difference. The slits are separated by distance $d = 150 \ m$. The intensity $I(\theta)$ is measured as a function of $\theta$,where $\theta$ is defined as shown. If $I_0$ is the maximum intensity,then $I(\theta)$ for $0 \le \theta \le 90^\circ$ is given by:

In a Young's double-slit experiment,the separation of the two slits is doubled. To keep the same spacing of fringes,the distance $D$ of the screen from the slits should be made

In a $YDSE$ with two identical slits,when the upper slit is covered with a thin,perfectly transparent sheet of mica,the intensity at the centre of the screen reduces to $75\%$ of the initial value. The second minimum is observed to be above this point and the third maximum below it. Which of the following cannot be a possible value of the phase difference caused by the mica sheet?