(a) Draw a ray diagram depicting the formation of the image by an astronomical telescope in normal adjustment.
(b) You are given the following three lenses. Which two lenses will you use as an eyepiece and as an objective to construct an astronomical telescope ? Give reason.
Lenses | Power (D) | Aperture (cm) |
3 | 8 | |
6 | 1 | |
10 | 1 |
(b) For the astronomical telescope, the objective has a large aperture and low power and eyepiece has large power and small aperture.
So, Objective lens :
Eyepiece lens :