Q14 of 52 Page 432

A Galilean telescope is 27 cm long when focussed to form an image at infinity. If the objective has a focal length of 30 cm, what is the focal length of the eyepiece?

Given data


Focal length of the objective lens of the telescope, fo = 30 cm


Length of the tube, L = 27 cm


The image will be formed at infinity


We know that ,



A Galilean telescope, concave lens as eyepiece lens –


So,




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 13

The eyepiece of an astronomical telescope has a focal length of 10 cm. The telescope is

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