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If tube length of astronomical telescope...

If tube length of astronomical telescope is 105 cm and magnifying power is 20 for normal setting, calculate the focal length of objective

A

100 cm

B

10 cm

C

20 cm

D

25 cm

Text Solution

Verified by Experts

The correct Answer is:
A
`m = (f_(o))/(f_(e)) = 20 `
and `L = f_(o) + f_(e) = 105 `
`f_(o) + (f_(o))/(20 ) = 105 rArr f_(o) = 100` cm.
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