Question

To construct a ray diagram we use two rays of light which are so chosen that it is easy to determine their directions after reflection from the mirror. Choose these two ras and state the path of these rays after reflection from a concave mirror . Use these two rays to find the nature and position of the image of an object plced at a distance of 15 cm from a concave mirror of focal length 10 cm.

Answer 1

Ray 1 . When and incident ray of light is parallel to the principal axis of a concave mirror, its reflected rays must pas through the principial focus of the concave mirror.
Ray 2 . A ray passing through the principal focus of a concave miror after reflection will emerge parallel to the principal axis.
Focal length `=` 10 cm.
Then centre of curvature , `C= 20 cm`
Object isplaced at 15 cm, i.e., between F & C
When the object formed is real, inverted and magnified . It is formed beyond C