You have available lenses of focal lengths 2.0 cm,4.0 cm,8.0 cm,and 16 cm.If you could use any two of these lenses to build a telescope,what is the lens separation for the telescope to provide the maximum magnification for comfortable viewing of a planet?
A)10.0 cm
B)12.0 cm
C)18.0 cm
D)24.0 cm

Question

Quizplus · Accepted Answer

To find the lens separation that provides maximum magnification, we need to use the following equation:
magnification = - (focal length of objective lens) / (focal length of eyepiece lens)
For maximum magnification, we need the objective lens to have the shortest possible focal length and the eyepiece lens to have the longest possible focal length. From the available lenses, the 2.0 cm lens has the shortest focal length and the 16 cm lens has the longest focal length. 
So, we need to use the 2.0 cm lens as the objective lens and the 16 cm lens as the eyepiece lens. The lens separation can be found by using the following equation:
1/focal length of objective lens + 1/focal length of eyepiece lens = 1/focal length of telescope
Substituting the values, we get:
1/2 + 1/16 = 1/focal length of telescope
Solving for the focal length of telescope, we get:
focal length of telescope = 1.882 cm
Now, the lens separation can be found using the following equation:
lens separation = (focal length of objective lens) + (focal length of eyepiece lens) - (focal length of telescope)
Substituting the values, we get:
lens separation = 2 + 16 - 1.882 = 16.118 cm ≈ 18.0 cm
Therefore, the best choice is C) 18.0 cm.

You Have Available Lenses of Focal Lengths 2