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प्रश्न
Assertion and reasoning type
- Assertion: Myopia is due to the increase in the converging power of eye lens.
- Reason: Myopia can be corrected with the help of concave lens.
विकल्प
If both assertion and reason are true and the reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
Assertion is true but reason is false.
Assertion is false but reason is true.
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उत्तर
If both assertion and reason are true but reason is not the correct explanation of assertion.
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संबंधित प्रश्न
What can you see in a completely dark room? If you switch on an electric bulb in this dark room as a light source, explain how you could now see:
(a) the electric bulb
(b) a piece of white paper
The focal length of a lens is +150 mm. What kind of lens is it and what is its power?
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?
Two lenses A and B have focal lengths of +20 cm and, −10 cm, respectively.
(a) What is the nature of lens A and lens B?
(b) What is the power of lens A and lens B?
(c) What is the power of combination if lenses A and B are held close together?
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.
A symmetric double convex lens in cut in two equal parts by a plane perpendicular to the principal axis. If the power of the original lens was 4 D, the power a cut-lens will be
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.
The focal length of a double convex lens is equal to the radius of curvature of either surface. What is the refractive index of its material?
