A plane mirror is made up of:

Q. A parallel plate capacitor has plate area $100c{m}^2$ and separation between the plates is 1 cm. A glass plat $(k_1=6)$ of thickness 6 mm and an ebonite plate $(k_2=4)$ of thickness 4 mm are inserted. Find C:

Q.

The thickness of a glass plate is measured to be 2.17 mm, 2.17 mm and 2.18 mm at three different places. Find the average thickness of the plate from this data.

Q. A 10 mm square hole can be cut in a 2 mm thick glass plate by

Q. There is an insect inside a cabin eying towards a thick glass plate $P_1$. Insect sees the images of light source across the glass plate $P_1$ outside the cabin. The cabin is made of thick glass plates of refractive index $\mu =\frac{3}{2}$ and thickness is 3 cm. The insect is eying from the middle of the cabin as shown in the figure. ( glass plates are partially reflective and consider only paraxial rays)
At what distance ( from the eye of insect) will the eye see the first image?

Q. The time taken by sunlight to cross a $5mm$ thick glass plate $(\mu =3/2)$ is