In an astronomical telescope, focal length of eye piece is `5 cm` and focal length of objective is `75 cm`. The final image is formed at the least distance of distinct vision `(=25 cm)` from the eye. What is the magnifying power of the telescope ?
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Here, `f_(e) = 5 cm, f_(0) = 75 cm, m = ?, d = 25` From `m = - (f_(0))/(f_(e))(1 + (f_(e))/(d)) = - (75)/(5)(1 + (5)/(25)) = -15 xx 1.2 = - 18.0`
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