Please answer this

 

Asked by kuppusamybose46 | 6th Mar, 2022, 05:16: PM

Expert Answer:

Figure shows the system of Concave lens and mirror as given in the question.
Focal length of concave lens is 20 cm. Distance between lens and mirror is 20 cm .
 
Since light is coming from far away distance , light rays are parallel to optical axis .
Then these parallel rays are getting diverged and incident on mirror and getting reflected as shown in figure.
 
Virtual image I is obtained by extending the reflected ray behind mirror at B and D as shown in figure.
 
ΔFBE and ΔIBE are congruent triangles .
 
Hence image distance behind the mirror is 40 cm that can be seen from figure.
 
Hence image is formed at 40 cm behind the mirror

Answered by Thiyagarajan K | 6th Mar, 2022, 08:13: PM