What happens to a ray travelling parallel to the principal axis ?

When the light rail traveling parallel to principal axis falls on concave mirror, then what is the part of reflected ray?

When a light ray travelling parallel to principal exis falls on concave mirror, then what is the path of reflected ray ?

What happens to ray that moves along the principal axis or moves through the centre of curvature ?

What happens if light rays parallel to principal exis fall on the concave mirror and draw ray diagram.

A converging mirror is placed on the right hand side of a converging lens as shown in the figure. The focal length of the mirror and the lens are 20 cm and 15 cm, respectively. The separation between the lens and the mirror is 40 cm and their principal axis coincide. A point source is placed on the principal axis at a distance d to the left of the lens. If the final beam comes out parallel to the principal axis, then the value of d is

A ray of light is incident on the hypotenuse of a right angled prism after travelling parallel to the base inside the prism. If mu is the refractive index of the material of the prism, the maximum value of the base angle for which light is totally reflected from the hypotenuse is