The magnifying power of an astronomical telescope is `5`. When it is set for normal adjustment, the distance between the two lenses is `24 cm`. Calculate the focal lengths of eye piece and objective lens.

The magnifying power of an astronomical telescope is `5`. When it is s

1.	The magnifying power of an astronomical telescope is `5`. When it is set for normal adjustment, the distance between the two lenses is `24 cm`. Calculate the focal lengths of eye piece and objective lens.
Answer» Correct Answer - `4 cm ; 30 cm` Here, `m = 5, L = 24 cm, f_o = ?, f_e = ?` As `m = (f_o)/(f_e) = 5 :. f_o = 5 f_e` Also, in normal adjustment `L = f_o + f_e = 5 f_e + f_e = 6 f_e` `f_e = (L)/(6) = (24)/(6) = 4 cm` and `f_o = 5 f_e = 5 xx 4 cm = 20 cm`.

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The magnifying power of an astronomical telescope is `5`. When it is set for normal adjustment, the distance between the two lenses is `24 cm`. Calculate the focal lengths of eye piece and objective lens.

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