Two objects A and B are placed at 15 cm and 25 cm from the pole in front of a concave mirror having radius of curvature 40 cm. The distance between images formed by the mirror is _______________.

'$$n$$' polarizing sheets are arranged such that each makes an angle $$45^{\circ}$$ with the preceeding sheet. An unpolarized light of intensity I is incident into this arrangement. The output intensity is found to be $$I / 64$$. The value of $$n$$ will be:

Two polaroide $$\mathrm{A}$$ and $$\mathrm{B}$$ are placed in such a way that the pass-axis of polaroids are perpendicular to each other. Now, another polaroid $$\mathrm{C}$$ is placed between $$\mathrm{A}$$ and $$\mathrm{B}$$ bisecting angle between them. If intensity of unpolarized light is $$\mathrm{I}_{0}$$ then intensity of transmitted light after passing through polaroid $$\mathrm{B}$$ will be: