A small telescope has an objective of focal length 140 cm and an eyepiece of focal length 5.0 cm. The magnifying power of the telescope for viewing a distant object is:
A
28
B
17
C
32
D
34
Step-by-Step Solution
Magnifying Power Formula: For an astronomical telescope in normal adjustment (viewing a distant object with the final image formed at infinity), the magnifying power (m) is given by the ratio of the focal length of the objective lens (fo) to the focal length of the eyepiece (fe).
m=fefo
Given Data:Focal length of objective, fo=140 cm Focal length of eyepiece, fe=5.0 cm
Calculation:m=5.0140=28
Conclusion: The magnifying power of the telescope is 28.
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