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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
विकल्प
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.
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 a convex mirror always produces a virtual image independent of the location of the object ?
Can a plane mirror ever form a real image?
Mark the correct options.
Which of the following (referred to a spherical mirror) do (does) not depend on whether the rays are paraxial or not?
(a) Pole
(b) Focus
(c) Radius of curvature
(d) Principal axis
A cylindrical vessel of diameter 12 cm contains 800π cm3 of water. A cylindrical glass piece of diameter 8.0 cm and height 8.0 cm is placed in the vessel. If the bottom of the vessel under the glass piece is seen by the paraxial rays (see figure), locate its image. The index of refraction of glass is 1.50 and that of water is 1.33.
A light ray is incident normally on the face AB of a right-angled prism ABC (μ = 1.50) as shown in figure. What is the largest angle ϕ for which the light ray is totally reflected at the surface AC?
Find the maximum angle of refraction when a light ray is refracted from glass (μ = 1.50) to air.
Find the angle of deviation suffered by the light ray shown in figure. The refractive index μ = 1.5 for the prism material.
A light ray, going through a prism with the angle of prism 60°, is found to deviate by 30°. What limit on the refractive index can be put from these data?
Write any one use for each of the following mirrors :
(a) Convex
(b) Concave
Name the physical principle on which the working of optical fibers is based.
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.
A parallel beam of light is allowed to fall on a transparent spherical globe of diameter 30cm and refractive index 1.5. The distance from the centre of the globe at which the beam of light can converge is ______ mm.
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:
