A point source of light $\mathrm{S}$ is placed in front of two large mirror as shown. Which of the following observers will be see only one image so $\mathrm{S}$ ?

 

A ray of light is incident oa a concave mirror. It is to the principal axis and its height from principal axis is equal to the focal length of the mirror. The ratio of the distance of point $\mathrm{B}$ to the distance of the focus from the centre of curvature is ($\mathrm{AB}$ is reflected ray)

What is the length of the image of the rod in mirror, according to the observer in air? (refractive index of the liquid is $\mathrm{\mu }$)

Two thin slabs of refractive indices ${\mathrm{\mu }}_1$ and ${\mathrm{\mu }}_2$ are placed parallel to each other in the $\mathrm{x}-\mathrm{y}$ plane. If the direction of propagation of a ray the two media are along the unit vectors ${\hat{\mathrm{r}}}_1=\mathrm{a}\hat{\mathrm{i}}+\mathrm{b}\hat{\mathrm{j}}$ and ${\hat{\mathrm{r}}}_2=\mathrm{c}\hat{\mathrm{i}}+\mathrm{d}\hat{\mathrm{j}}$ then we have 

A point source $\mathrm{S}$ is placed at the bottom of different layers as shown in the figure. The refractive index of bottommost layer is ${\mathrm{\mu }}_0$. The refractive index of any other upper layer is $\mathrm{\mu }\left(\mathrm{n}\right)={\mathrm{\mu }}_0+\frac{{\mathrm{\mu }}_0}{4\mathrm{n}-18}$ A ray of light with angle $\mathrm{i}=30°$ start from the source $\mathrm{S}$. Total internal reflection takes place at the upper surface of layer having $\mathrm{n}$ equal to