Ray Optics and Optical Instruments

Related Questions

• A diver in a swimming pool wants to signal his distress to a person lying on the edge of the pool by flashing his water proof flash light

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• A lens of refractive index $n$ is put in a liquid of refractive index $n'$ of focal length of lens in air is $f$, its focal length in liquid will be

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• 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

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• A ray of light passes through four transparent media with refractive indices ${{\mu }_{1}}.{{\mu }_{2}}{{\mu }_{3}},\text{ and}\,{{\mu }_{4}}$ as shown in the figure. The surfaces of all media are parallel. If the emergent ray CD is parallel to the incident ray AB, we must have

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• The reason of seeing the Sun a little before the sunrise is

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