- Question Answer
- 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 mi
. 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 mi
Choose these two rays a d 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 placed at a distance of 15 cm from a concave mirror of focal length 10 cm.
Sol. Ray 1. When an incident ray of light is parallel to the principal axis of a concave mirror, its reflected ray must pass through the principal focus of the concave mirror.
Ray 2. A ray passing through. the principal focus of a concave mirror after reflection will emerge parallel to the principal axis.
• Focal length = 10 cm; Then centre of curvature, C = 20 cm
• Object is placed at 15 cm, i.e., between F & C
When the object is between F and C (centre of curvature):
The image formed is real, inverted and magnified. It is formed beyond C.