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प्रश्न
State the condition when a lens is called an equi-convex or equi-concave.
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उत्तर
A lens is called an equiconvex or equiconcave when radii of curvature of the two surfaces of lens are equal.
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संबंधित प्रश्न
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) |
Study the diagram shown in the following Figure.
Name the lens LL’ and draw its outline.
The diagram given below shows the position of an object OA in relation to a converging lens L whose foci are at F1 and F2.
- Draw two rays to locate the position of the image.
- State the position of the image with reference to the lens.
- Describe three characteristics of the image.
- Describe how the distance of the image from the lens and its size change as the object is moved towards F1.
A ray of light incident parallel to the principal axis of a lens, passes undeviated after refraction.
A ray of light incident at the optical centre of lens, passes undeviated after refraction.
(a) Draw a sketch to show how a lens is able to produce an image of the sun on a paper screen.
(b)(i) Would you regard the rays from the sun as being divergent, parallel or convergent?
(ii) What is the name given to the point where such rays meet after they have passed through the lens?
(iii) How does the image of the sun sometimes burn a paper screen?
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.
Make the rrect choices in the following items :
An object is placed 50 cm from a connverging lens of focal length 30 cm. The image produced would be
Complete the following diagram and state what happens to the ray of light after refraction through the lens.
Draw a ray diagram to show the image formed by a convex lens when the object is placed between F and 2F.
