Question

You are given following three lenses. Which two lenses will you use as an eyepiece and as an objective to construct an astronomical telescope?

Lens	Power (P)	Aperture (A)
L1	3D	8 cm
L2	6D	1 cm
L3	10D	1 cm

 

Answer 1

For constructing an astronomical telescope, the objective should have the maximum diameter. Of the three lenses given, L1 has the maximum diameter.

The eyepiece should have the highest power for better magnification. Therefore, we use lens L3.