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The focal length of the lensese of an as...

The focal length of the lensese of an astronomical telescope are 50 cm and 5 cm. The length of the telescope when the image is formed at the least distance of distinct vision is

A

45cm

B

55cm

C

`(275)/(6)` cm

D

`(325)/(6)` cm

Text Solution

Verified by Experts

The correct Answer is:
D
L = `f_(o) + u_(e) = f_(o) + (f_(e) D)/(f_(e) + D)`
`= 50 + (5 xx 25)/(5 + 25) = (325)/(6) ` cm .
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