Problem 10.1. An object 4 cm tall is placed near the axis of a thin converging lens. If the focal length of the lens is 25 cm, where will the image be formed and what will be the size of the image? Sketch the principal ray diagram...
Data
Focal length f =25cm
Size of object ho =4cm
Object distance p =33.33cm
To fin
Image distance q=?
Size of images =?
Solution
Using this lens formula is 1/f=1/p+ 1/q 》
1/q=1/f - 1/p =1/25 - 1/33.33cm
1/q=33.33 _25/25×33.33 = 8.33/8.33.25=0.01
q=1/0.001 = 100cm. Q = 100cm Ans
Image hight can be found by magnification formula as
Hį/ho=q/p
Hi= q/p ho = 100 /33.33 ×4 =12cm
