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प्रश्न
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संबंधित प्रश्न
Explain optical centre of a lens with the help of proper diagram(s).
In the following figure (a) and (b), F1 and F2 are positions of the two foci of thin lenses. Draw the path taken by the light ray AB after it emerges from each lens.
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| (a) |
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| (b) |
In the diagram below, XX’ represents the principal axis, O the optical centre and F the focus of the lens. Complete the path of rays A and B as they emerge out of the lens.
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| (a) | (b) |
Distinguish between a real and a virtual image.
A ray of light incident parallel to the principal axis of a lens, passes undeviated after refraction.
State the condition of the following:
A lens has both its focal lengths equal.
What type of lenses are used in spectacles worn by an old lady for knitting?
In the following diagram , the object and the image formed by the respective lenses are shown. Complete the ray diagram, and locate the focus. Find the focal length of the lens.

A lens forms the image of an object placed at a distance of 45 cm from it on a screen placed at a distance 90 cm on the other side of it. Name the kind of lens.
The diagram showed a lens as a combination of one glass block and two prisms. Complete the ray diagram and show the part of the incident ray AB after passing through the lens.
(i) Name of the lens formed by the combination.
(ii) What is the line XX’ called?
(iii) Mark the focus F.





