Question:
An astronomical telescope of tenfold angular
magnification has a length of 44 cm. The focal
length of the objective is
An astronomical telescope of tenfold angular
magnification has a length of 44 cm. The focal
length of the objective is
Updated On: Jul 4, 2024
- 44 cm
- 440 cm
- 4 cm
- 40 cm.
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The Correct Option is D
Solution and Explanation
Length of astronomical telescope
$(f_0 + f_e ) = 44 cm $ and ratio of focal length of the
objective lens to that of the eye piece $\frac{f_0}{f_e} = 10$
From the given ratio, we find that $ f_0 =10 f_e$
Therefore $ 10f_e +f_e = 44 \, \, or \, \, f_e = 4 cm $
and focal length of the objective $(f_0)$
$= 44- f_e = 44-4 =40 cm $
$(f_0 + f_e ) = 44 cm $ and ratio of focal length of the
objective lens to that of the eye piece $\frac{f_0}{f_e} = 10$
From the given ratio, we find that $ f_0 =10 f_e$
Therefore $ 10f_e +f_e = 44 \, \, or \, \, f_e = 4 cm $
and focal length of the objective $(f_0)$
$= 44- f_e = 44-4 =40 cm $
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