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A Galilean telescope of 10-fold magnifi...

A Galilean telescope of `10`-fold magnification has the length of `45 cm` when adjusted to infinity. Determine :
(a) the focal lengths of the telescope's objective and ocular,
(b) by what distance the ocualr should be displaced to adjust the telescope to the distance of `50 m.`

A

50 cm, 5cm

B

`50cm, -5cm`

C

`(450)/(11)cm, (45)/(11)cm`

D

`(450)/(11)cm, (-45)/(11)cm`

Text Solution

Verified by Experts

The correct Answer is:
B
For Galilean telescope eyepiece is diverging and final image is erect.
`f_(0)+(f_(0))=45cm`
`-f_(0)//f_(0)=10`
`rArrf_(0)=50cm, f_(e)=-5cm`
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