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प्रश्न
The rays of different colours fail to converge at a point after going through a converging lens. This defect is called
पर्याय
spherical aberration
distortion
coma
chromatic aberration.
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उत्तर
chromatic aberration
When light rays of different colours do not converge at the same point after passing through a converging lens, it is called chromatic aberration. This happens because a lens has different refractive indices for different colours, i.e, for different wavelengths of light.
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संबंधित प्रश्न
Calculate the distance of an object of height h from a concave mirror of radius of curvature 20 cm, so as to obtain a real image of magnification 2. Find the location of the image also.
Use the mirror equation to show that an object placed between f and 2f of a concave mirror produces a real image beyond 2f.
Use the mirror equation to show that a convex mirror always produces a virtual image independent of the location of the object.
Using mirror formula, explain why does a convex mirror always produce a virtual image.
An object is kept on the principal axis of a concave mirror of focal length 10 cm. at a distance of 15
cm from its pole. The image formed by the mirror is:
(a) Virtual and magnified
(b) Virtual and diminished
(c) Real and magnified
(d) Real and diminished
Use the mirror equation to show that an object placed between f and 2f of a concave mirror forms an image beyond 2f.
Use the mirror equation to show a convex mirror always produces a virtual image independent of the location of the object ?
Can a plane mirror ever form a real image?
A point source of light is placed in front of a plane mirror.
Mark the correct options.
A small object is placed at the centre of the bottom of a cylindrical vessel of radius 3 cm and height 4 cm filled completely with water. Consider the ray leaving the vessel through a corner. Suppose this ray and the ray along the axis of the vessel are used to trace the image. Find the apparent depth of the image and the ratio of real depth to the apparent depth under the assumptions taken. Refractive index of water = 1.33.
Write any one use for each of the following mirrors :
(a) Convex
(b) Concave
The figure below shows the positions of a point object O, two lenses, a plane mirror and the final image I which coincides with the object. The focal length of the convex lens is 20 cm. Calculate the focal length of the concave lens.
The focal length f is related to the radius of curvature r of the spherical convex mirror by ______.
Car B overtakes car A at a relative speed of 40 ms-1. How fast will the image of car B appear to move in the mirror of focal length 10 cm fitted in car A, when car B is 1.9 m away from car A?
When a clock is viewed in a mirror, the needles exhibit a time which appears to be 8:20. Then the actual time will be:
Two plane mirrors are inclined at an angle of 40°. The possible number of images of an object placed at point P would be?
A point object is placed at a distance of 30 cm from a convex mirror of a focal length of 30 cm. What is the separation between the image and the object?
A convex lens of focal length 15 cm is placed coaxially in front of a convex mirror. The lens is 5 cm from the pole of the mirror. When an object is placed on the axis at a distance of 20 cm from the lens, it is found that the image coincides with the object. Calculate the radius of curvature of the mirror - (consider all-optical event):
