Consider a light beam incident from air to a glass slab at Brewster's angle as shown in the figure. A polaroid is placed in the path of the emergent ray at point $P$ and rotated about an axis passing through the centre and perpendicular to the plane of the polaroid. Then:
               

Consider a ray of light incident from the air onto a slab of glass (refractive index $n$) of width $d$, at an angle $\theta$. The phase difference between the ray reflected by the top surface of the glass and the bottom surface is:
1. $\frac{4 \pi d}{\lambda}\left(1-\frac{1}{n^2} \sin ^2 \theta\right)^{1 / 2}+\pi$
2. $\frac{4 \pi d}{\lambda}\left(1-\frac{1}{n^2} \sin ^2 \theta\right)^{1 / 2}$
3. $\frac{4 \pi d}{\lambda}\left(1-\frac{1}{n^2} \sin ^2 \theta\right)^{1 / 2}+\frac{\pi}{2}$
4. $\frac{4 \pi d}{\lambda}\left(1-\frac{1}{n^2} \sin ^2 \theta\right)^{1 / 2}+2\pi$

In Young's double-slit experiment, the source is white light. One of the holes is covered by a red filter and another by a blue filter. In this case:

                                         
At $P_2$ on the screen, there is a hole and behind $P_2$ is a second $2\text-$slit arrangement with slits $S_3, S_4$ and a second screen behind them. 

 Two Sources $S_1$ and $S_2$ of intensity $I_1$ and $I_2$ are in front of a screen [Fig.(a)]. The pattern of intensity distribution seen in the central portion is given by Fig.(b).

In this case, which of the following statements are true?

Choose the correct option:

Consider sunlight incident on a pinhole of width $10^{3}~\mathring{{A}}$. The image of the pinhole seen on a screen shall be:

Choose the correct option from the given ones:

Consider the diffraction pattern for a small pinhole. As the size of the hole is increased:

For light diverging from a point source: