Optics Question 396
Question: When a telescope is adjusted for parallel light, the distance of the objective from the eye piece is found to be 80 cm. The magnifying power of the telescope is 19. The focal lengths of the lenses are
[MP PMT 1992; Very similar to DPMT 2004]
Options:
A) 61 cm, 19 cm
B) 40 cm, 40 cm
C) 76 cm, 4 cm
D) 50 cm, 30 cm
Show Answer
Answer:
Correct Answer: C
Solution:
$ f _{o}+f _{e}=80 $ and $ \frac{f _{o}}{f _{e}}=19 $
Therefore fo = 76 and fe = 4 cm.
