In: Physics
A two lens magnifying system uses lenses of focal lengths 2.5 and 9.5 cm for the objective and eyepiece, respectively. The two lenses are positioned 23 cm apart. An object for study is placed 3.0 cm in front of the objective lens. Find the magnification of the final image.
Solution:
Given,
focal length of objective
focal length of eyepiec
The distance between objective nad eyepiece is 23cm.
(i) Refraction on Objective:
object distance
focal length
image distance =
By lens formula,
Magnification
(ii) Refraction on eyepiece:
The image formed by objective serves as the object for eyepiece. Distance between the two lens is 23cm. The image formed by objective is 15cm right to the objective. So, it will be 23-15=8cm infornt of eyepiece.
object distance
focal length
image distance =
By lens formula,
Magnification
The magnification of the final image is given by,
The magnification of the final image is -31.5