Same chapter3 marksDifficulty: Medium
State the lens maker's formula and explain each symbol.
Ray Optics and Optical Instruments
3 marksDifficulty: Medium
Distinguish between a compound microscope and an astronomical telescope in terms of the focal lengths used.
Original Khojo Papers practice question — not from a past board paper.
Answer
In a compound microscope both the objective and the eyepiece have short focal lengths, and the objective's is the shorter of the two, so that a nearby object is greatly magnified. In an astronomical telescope the objective has a long focal length and a large aperture and the eyepiece a short focal length, so that a distant object subtends a larger angle.
No citable source has been recorded for this record. Treat it as practice material, not as fact.
Explanation
The magnifying power of a telescope in normal adjustment is f0/fe.
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