A point object is placed at a distance of 20 cm from a thin plano convex lens of focal length 15 cm. The plane surface of the lens is now silvered. The image created by the system is at
| A. |
60 cm to the left of the system |
| B. |
60 cm to the right of the system |
| C. |
12 cm to the left of the system |
 |
| D. |
12 cm to the right of the system |
Refraction from lens; `1/v_1-1/-20=1/15`
so, v=60 cm `->` +ve direction
Ie, first image is formed at 60 cm to the right of lens system.
Reflection from mirror:
After reflection from the mirror , the second image will be formed at a distance of 60 cm to the left of lens system.
`1/v_3-1/60=1/15` `larr` +ve direction
Or `v_3=12 cm`
Therefore, the final image is formed at 12 cm to the left of the lens system.