Light from a point source falls on a small area placed perpendicular to the incident light. If the area is rotated about the incident light by an angle of $60^o$,by what fraction will the illuminance change?

In interference and diffraction, the light energy is redistributed. If it reduces in one region, producing a dark fringe, it increases in another region, producing a bright fringe. Statement $A$: As there is no gain or loss of energy, these phenomena are consistent with the principle of conservation of energy. Statement $B$: Diffraction and interference are characteristics exhibited only by light waves. Choose the correct answer from the options given below:

Evidence for the wave nature of light cannot be obtained from

Column $I$ shows four situations of standard Young's double slit arrangement with the screen placed far away from the slits $S_1$ and $S_2$. In each of these cases $S_1 P_0 = S_2 P_0$,$S_1 P_1 - S_2 P_1 = \lambda / 4$ and $S_1 P_2 - S_2 P_2 = \lambda / 3$,where $\lambda$ is the wavelength of the light used. In the cases $B, C$ and $D$,a transparent sheet of refractive index $\mu$ and thickness $t$ is pasted on slit $S_2$. The thicknesses of the sheets are different in different cases. The phase difference between the light waves reaching a point $P$ on the screen from the two slits is denoted by $\delta(P)$ and the intensity by $I(P)$. Match each situation given in Column $I$ with the statement$(s)$ in Column $II$ valid for that situation.

Column $I$	Column $II$
$(A)$ No sheet	$(p)$ $\delta(P_0) = 0$
$(B)$ $(\mu-1)t = \lambda / 4$	$(q)$ $\delta(P_1) = 0$
$(C)$ $(\mu-1)t = \lambda / 2$	$(r)$ $I(P_1) = 0$
$(D)$ $(\mu-1)t = 3\lambda / 4$	$(s)$ $I(P_0) > I(P_1)$
	$(t)$ $I(P_2) > I(P_1)$

The figure shows a schematic diagram of Young's Double Slit Experiment. If the distance $D$ between the slits and the screen is varied,choose the correct statement$(s)$.

Statement $(S)$: Using Huygen's eye-piece,measurements can be taken but are not correct.
Reason $(R)$: The cross wires,scale,and final image are not magnified proportionately because the image of the object is magnified by two lenses,whereas the cross-wire scale is magnified by one lens only.
Identify the correct option from the following: