CBSE Class 12 Physics 2017 Delhi Set 2 Paper

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Question : 3
Total: 8
Why should the objective of a telescope have large focal length and large aperture? Justify your answer.
Solution:  
Reasons for having large focal length and large aperture of objective of telescope and their justification.

Large focal length : to increase magnifying power
(m=
f0
fe
)

Large aperture : to increase resolving power. 12
(RP=
2a
1.22λ
)
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