- Draw a labelled ray diagram to obtain the real image formed by an astronomical telescope in normal adjustment position. Defineits magnifying power.
- You are given three lenses of power 0.5 D, 4 D and 10 D to design a telescope.
- Which lenses should he used as objective and eyepiece? Justify your answer.
- Why is the aperture of the objective preferred to be large?
CBSE OUTSIDE DELHI - SET 2 CENTRAL 2016
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Definition - It is the ratio of the angle subtended at the eye, by the final image, to the angle which the object subtends at the lens, or the eye.
- Objective=.5D
$\text{M} = \frac{\text{f}_{o}}{\text{f}_{e}} = \frac{\text{p}_{e}}{\text{p}_{o}}$
- High resolving power/Brighter image/lower limit of resolution.
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