InterviewSolution
Saved Bookmarks
| 1. |
A convex lens of focal length 40 cm is in contact with a concave lens of focal length 25 cm. The power of the combination isA. `-1.25D`B. `-6.5D`C. `+6.5D`D. `+1.25D` |
|
Answer» Correct Answer - A (a) Focal length of the combination, `1/F==1/(f_(1))+1/(f_(2))` `rArr1/F=1/(+40)+1/(-25)` `rArrF=-200/3cm` As, Power,P`=100/F=100/((-200//3))=1.5D` |
|