## 3 Example 7. The image of needle placed 10 cm from a lens is formed on a wall 20 cm on the other side of the lens. Find the f

Question

3

Example 7. The image of needle placed 10 cm from a

lens is formed on a wall 20 cm on the other side of the

lens. Find the focal length of the lens and size of image

formed if the size of the needle is 25 cm

Solution : Given, u=-10 cm, u = + 20 cm. f = 2,7

= ?

h = 2.5 cmâ€‹

in progress
0

Math
3 weeks
2021-09-10T16:35:00+00:00
2021-09-10T16:35:00+00:00 1 Answer
0 views
0
## Answers ( )

Answer:Given–Now,byusinglensformula–Therefore,thefocallengthofthelensis6.67cm.Therefore,thesizeoftheimageis5cm.