InterviewSolution
Saved Bookmarks
| 1. |
A screen is placed `80 cm` from an object. The image of the object on the screen is formed by a convex lens at two different locations separated by `10 cm`. Calculate the focal length of the lens used. |
|
Answer» Correct Answer - `19.7 cm` Here, `D = 80 cm, d = 10 cm, f = ?` `f = (D^(2) - d^(2))/(4D) = (80^(2) - 10^(2))/(4 xx 80) = (6300)/(320) = 19.7 cm` |
|