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प्रश्न
A ray of light after refraction through a lens emerges parallel to the principal axis of the lens. The incident ray either passes through ______.
विकल्प
its optical centre
its first focus
its second focus
its centre of curvature of the first surface
उत्तर
A ray of light after refraction through a lens emerges parallel to the principal axis of the lens. The incident ray either passes through its first focus.
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संबंधित प्रश्न
State the condition when a lens is called an equi-convex or equi-concave.
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) |
A ray of light incident at the optical centre of lens, passes undeviated after refraction.
For an object placed at a distance 20 cm in front of a convex lens, the image is at a distance 20 cm behind the lens. The focal length of the convex lens is ______.
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.
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.
Complete the following diagram and state what happens to the ray of light after refraction through the lens.
Complete the following diagram and state what happens to the ray of light after refraction through the lens.
In the following diagram, L1 and L2 are the two convex lense placed at separation equal to the sum of focal lengths of the two lenses. A and B are the two rays of light incident on the lens L1. Complete the path of rays till they emerge out of the lens L2.
What principles have you used in completing the diagram?
