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प्रश्न
Name one of the common defects of vision and the type of lens used to remove it.
उत्तर
Myopia is one of the common defects of vision because of which a person is able to see nearby objects, but not distant objects, clearly. Concave lenses are used to correct this defect.
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संबंधित प्रश्न
Define the principal focus of a concave lens.
Fill in the following blank with suitable word:
Lenses refract light to form images: a..................... lens can form both real and virtual images, but a diverging lens forms only ...................... images.
Give the position, size and nature of image of formed by a concave lens when the object is placed:
anywhere between optical centre and infinity.
An object is placed 10 cm from a lens of focal length 5 cm. Draw the ray diagrams to show the formation of image if the lens is diverging.
When an object is placed 10 cm in front of lens A, the image is real, inverted, magnified and formed at a great distance. When the same object is placed 10 cm in front of lens B, the image formed is real, inverted and same size as the object.
What is the nature of lens A?
Calculate the image distance for an object of height 12 mm at a distance of 0.20 m from a concave lens of focal length 0.30 m, and state the nature and size of the image.
A person finds difficulty in seeing nearby objects clearly. His vision can be corrected by using spectacles containing:
(a) converging lenses
(b) diverging lenses
(c) prismatic lenses
(d) chromatic lenses
Out of the two lenses, one concave and the other convex, state which one will show the divergent action on a light beam. Draw diagrams to illustrate your answer.
The following diagram in given below shows an object OA and its virtual image IB formed by a lens.
An object is placed on the axis of a lens. An image is formed by refraction in the lens. For all positions of the object on the axis of the lens, the positions of the image are always always between the lens and the object Draw a ray diagram to show it.
