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प्रश्न
State the condition for the following a ray passes undeviated through the lens .
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उत्तर
If a ray passes undeviated through the lens it is incident at the optical centre of the lens.
संबंधित प्रश्न
What is meant by a power of a lens? Define its SI unit.
Name the physical quantity whose unit is dioptre.
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 combination of two lenses X and Y is 5 D. If the focal length of lens X be 15 cm :
(a) calculate the focal length of lens Y.
(b) state the nature of lens Y.
What is the unit of power of a lens? Define the unit of power of a lens.
A combination of lenses for a camera contains two converging lenses of focal lengths 20 cm and 40 cm and a diverging lens of focal length 50 cm. Find the power and focal length of the combination.A optical instrument in which the above arrangement of convex lens is used is a convex lens used to burn paper by focusing sunlight.
How does focal length of a lens change when red light incident on it is replaced by violet light? Give reason for your answer.
A 5.0 diopter lens forms a virtual image which is 4 times the object placed perpendicularly on the principal axis of the lens. Find the distance of the object from the lens.
The focal length of a concave lens is 20 cm. The focal length of a convex lens is 25 cm. These two are placed in contact with each other. What is the power of the combination? Is it diverging, converging or undeviating in nature?
When monochromatic red light is used instead of blue light in a convex lens, its focal length will ______.
