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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
A student uses a lens of focal length 40 cm and another of –20 cm. Write the nature and power of each lens
The focal length of a convex lens is 25 cm. What is its power?
A combination of lenses for a camera contains two converging lenses of focal lengths 20 cm and 40 cm and a diverging lens of focal length 50 cm. Find the power and focal length of the combination.A optical instrument in which the above arrangement of convex lens is used is a convex lens used to burn paper by focusing sunlight.
How is the power of a lens related to its focal length?
Mohan obtained a sharp inverted image of a distant tree on the screen placed behind the lens. He then moved the screen and tried to look through the lens in the direction of the object. He would see:
(1) a blurred image on the wall of the laboratory.
(2) an erect image of the tree on the lens.
(3) no image as the screen has been removed
(4) an inverted image of the tree at the focus of the lens.
If the lens is of focal length 25 cm. Calculate the power of the lens.
Find the power of a convex lens of focal length of + 25 cm.
The power of lens depends on the focal length of the lens
The same size images are formed by a convex lens when the object is placed at 20 cm or at 10 cm from the lens. The focal length of convex lens is ______ cm.
The lens of power + 1·0 D is ______.
