Optics Question 426
Question: An astronomical telescope has a magnifying power 10. The focal length of eyepiece is 20 cm. The focal length of objective is
[MP PMT 2002, 03; Pb. PET 2004]
Options:
A) 2 cm
B) 200 cm
C) $ \frac{1}{2}cm $
D) $ \frac{1}{200}cm $
Show Answer
Answer:
Correct Answer: B
Solution:
$ m=\frac{f _{o}}{f _{e}}\Rightarrow 10=\frac{f _{o}}{20}\Rightarrow f _{o}=200\ cm $
