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प्रश्न
The following diagram shows the object O and the image I formed by a lens. Copy the diagram and on it mark the positions of the lens LL’ and focus (F). Name the lens.
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उत्तर
The complete diagram is shown in the figure in which the position of the lens has been marked by the letter LL’ and the focus as F. The lens is convex (or converging).
संबंधित प्रश्न
Define 1 dioptre of power of a lens.
You have two lenses A and B of focal lengths +10 cm and –10 cm, respectively. State the nature and power of each lens. Which of the two lenses will form a virtual and magnified image of an object placed 8 cm from the lens? Draw a ray diagram to justify your answer
Name the physical quantity whose unit is dioptre.
A lens has a focal length of, −10 cm. What is the power of the lens and what is its nature?
A convex lens of power 5 D and a concave lens of power 7.5 D are placed in contact with each other. What is the :
(a) power of this combination of lenses?
(b) focal length of this combination of lenses?
On reducing the focal length of a lens, its power ______.
A convex lens produces a double size real image when an object is placed at a distance of 18 cm from it. Where should the object be placed to produce a triple size real image?
If the lens is of focal length 25 cm. Calculate the power of the lens.
Match the following:
| Column - I | Column - II | ||
| 1 | Retina | a | Path way of light |
| 2 | Pupil | b | Far point comes closer |
| 3 | Ciliary muscles | c | near point moves away |
| 4 | Myopia | d | Screen of the eye |
| 5 | Hypermetropia | e | Power of accommodation |
When monochromatic red light is used instead of blue light in a convex lens, its focal length will ______.
