Appeared in: 2024 (2 sets)
The magnifying power of an astronomical telescope is 24. In normal adjustment, distance between its two lenses is 150 cm. Find the focal length of the objective lens.
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Step 1 (Formula / Governing Law & Given Data): [0.5 Mark]
For an astronomical telescope in normal adjustment (final image formed at infinity):
- Magnifying power ($m$) is given by: $$m = \frac{f_o}{f_e}$$