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The focal length of the objective of a ...

The focal length of the objective of a terrestical telescope is 80cm and it is adjusted for parallel rays, then its power is 20. If the focal length of erecting lens is 20cm, then full length of the telescope will be

A

84

B

100

C

124

D

164

Text Solution

Verified by Experts

The correct Answer is:
D
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AAKASH SERIES-OPTICAL INSTRUMENTS -PRACTICE SHEET (EXERCISE -I) (OPTICAL INSTRUMENTS) (LEVEL-I (MAIN)) (SUBJECTIVE OBJECTIVE TYPE QUESTIONS)
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