Questions in Ray Optics and Optical Instruments

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In a terrestrial telescope, the focal length of objective is 90 cm, of inverting lens is $5\,cm$and of eye lens is $6\,cm.$If the final image is at 30 cm, then the magnification will be
The resolving power of a telescope depends on
Four lenses of focal length + 15 cm, + 20cm, + 150cm and + 250 cm are available for making an astronomical telescope. To produce the largest magnification, the focal length of the eye-piece should be
In an astronomical telescope, the focal length of objective lens and eye-piece are 150 cm and 6 cm respectively. In case when final image is formed at least distance of distinct vision. the magnifying power is
In a laboratory four convex lenses ${{L}_{1}},\,{{L}_{2}},\,{{L}_{3}}$ and ${{L}_{4}}$ of focal lengths 2, 4, 6 and 8 cm respectively are available. Two of these lenses form a telescope of length 10 cm and magnifying power 4. The objective and eye lenses are
A telescope has an objective of focal length 50 cm and an eye piece of focal length 5 cm. The least distance of distinct vision is 25 cm. The telescope is focussed for distinct vision on a scale 200 cm away. The separation between the objective and the eye-piece is
The resolving power of a telescope whose lens has a diameter of 1.22 m for a wavelength of 5000 Å is
To increase both the resolving power and magnifying power of a telescope
A Galileo telescope has an objective of focal length $100cm$ and magnifying power $50$. The distance between the two lenses in normal adjustment will be
An astronomical telescope has a magnifying power 10. The focal length of eyepiece is 20 cm. The focal length of objective is

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