A biconvex lens of refractive index $n_2$ is placed such that the refractive index of the surrounding media is as shown. Then the lens 

In the figure shown a point object $O$ is placed in the air on the principal axis. The radius of curvature of the spherical surface is $60 \mathrm{cm}$. If is the final image formed after all the refractions and reflections.

A particle is moving towards a fixed convex mirror. The image also moves. If $V_{\mathrm{i}}=$speed of image and $V_{\mathrm{O}}=$speed of the object, then

A parallel beam of light is incident normally on the flat surface of a hemisphere of radius $6 \mathrm{cm}$ and refractive index $1.5$, placed in the air as shown in the figure $\left(\mathrm{i}\right)$. Assume paraxial ray approximation.

A ray is an incident on a refracting surface of refractive index $\mu$ at an angle of incidence $i$ and the corresponding angle of refraction is $r$. The deviation of the ray after refraction is given by $\delta =i-r$. Then, one may conclude that

A convex lens and concave lens are kept in contact and the combination is used for the formation of the image of a body by keeping it at different places on the principal axis. The image formed by this combination of lenses can be

A ray of light travelling in water is incident on its surface open to air. The angle of incidence is $\theta$, which is less than the critical angle. Then, there will be