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प्रश्न
What type of lenses are used in spectacles worn by an old lady for knitting?
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उत्तर
A converging lens of suitable focal length is used in the spectacles worn by an old lady for knitting.
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संबंधित प्रश्न
What is a lens?
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 figure, (a) and (b), F1 and F2 are the two foci of thin lenses and AB is the incident ray. Complete the diagram to show the path of the ray AB after refraction through each lens.
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| (a) |
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| (b) |
A ray of light after refraction through a lens emerges parallel to the principal axis of the lens. The incident ray either passes through ______.
The diagram given below shows the position of an object OA in relation to a converging lens whose foci are at F1 and F2.
Describe three characteristic of the image.
A ray of light incident parallel to the principal axis of a lens, passes undeviated after refraction.
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.
In fig., a real image of a point objert O is formed, Which of the following statements is true about each of the arrangements?
- The object is at the principle focus of the lens.
- The focal length of the lens is 17 cm.
- If the mirror is moved so that it is 6 cm from the lens image will also move.
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.
