Which of the following statements are incorrect for spherical mirrors.

A ray of monochromatic light is incident on the plane surface of separation between two media $x$ and $y$ with the angle of incidence $i$ in the medium $x$ and angle of refraction $r$ in the medium $y$. The graph shows 

Two refracting media are separated by a spherical interface as shown in the figure. $P{P}^{\text{'}}$ is the principal axis, ${\mu }_1$ and ${\mu }_2$ are the refractive indices of the medium of incidence and medium of refraction, respectively. Then

The values of $d_1$ and $d_2$ for final rays to be parallel to the principal axis are (focal lengths of the lenses are written above the respective lenses in the given figure)

An object $O$ is kept in front of a converging lens of a focal length $30 \mathrm{cm}$ behind which there is a plane mirror at $15 \mathrm{cm}$ from the lens as shown in the figure.

If symmetrical biconcave thin lens is cut into two identical halves. They are placed in different ways as shown.

A narrow beam of white light goes through a slab having parallel faces.