Question:
The magnifying power of a telescope is \(m\). If the focal length of the eye piece is doubled, then its magnifying power becomes:
The magnifying power of a telescope is \(m\). If the focal length of the eye piece is doubled, then its magnifying power becomes:
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Magnification is inversely proportional to eyepiece focal length.
Updated On: Apr 16, 2026
- \(2m\)
- \(3m\)
- \( \frac{m}{2} \)
- \( \frac{m}{4} \)
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Verified By Collegedunia
The Correct Option is D
Solution and Explanation
Concept:
Magnifying power of telescope:
\[
m = \frac{f_o}{f_e}
\]
Step 1: New focal length.
\[ f_e' = 2f_e \]
Step 2: New magnification.
\[ m' = \frac{f_o}{f_e'} = \frac{f_o}{2f_e} = \frac{m}{2} \]
Step 1: New focal length.
\[ f_e' = 2f_e \]
Step 2: New magnification.
\[ m' = \frac{f_o}{f_e'} = \frac{f_o}{2f_e} = \frac{m}{2} \]
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