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प्रश्न
Increase in the converging power of eye lens cause ‘hypermetropia'
पर्याय
True
False
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उत्तर
True
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संबंधित प्रश्न
What is the focal length of a convex lens of focal length 30 cm in contact with a concave lens of focal length 20 cm? Is the system a converging or a diverging lens? Ignore thickness of the lenses.
Which type of lens has (a) a positive power, and (b) a negative power?
The focal length of a convex lens is 25 cm. What is its power?
A doctor has prescribed a corrective lens of power, −1.5 D. Find the focal length of the lens. Is the prescribed lens diverging or converging?
An object of height 4 cm is placed at a distance of 15 cm in front of a concave lens of power, −10 dioptres. Find the size of the image.
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?
The power of a lens is + 1.0 D is :
If there is a convex lens of focal length 75 cm and a concave lens of focal length 40 cm, then calculate their combined power and combined focal length.
Define power of a lens. What is its unit? One student uses a lens of focal length 50 cm and another of –50 cm. What is the nature of the lens and its power used by each of them?
In what unit is the power of a lens expressed?
