Optics Question 395
Question: An opera glass (Gallilean telescope) measures 9 cm from the objective to the eyepiece. The focal length of the objective is 15 cm. Its magnifying power is
[DPMT 1988]
Options:
A) 2.5
B) 2/5
C) 5/3
D) 0.4
Show Answer
Answer:
Correct Answer: A
Solution:
$ f _{o}-f _{e}=9\ cm $ and $ f _{e}=f _{o}-9=15-9=6 $ cm
$ \Rightarrow m=\frac{f _{o}}{f _{e}}=\frac{15}{6}=2.5 $
