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प्रश्न
Power of a lens is – 4D, then its focal length is
विकल्प
4m
–40m
–0.25 m
–2.5 m
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उत्तर
– 0.25 m
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संबंधित प्रश्न
State the power of a lens S.I. unit.
What is the power of a convex lens of focal length 0.5 m?
A convex lens of focal length 25 cm and a concave lens of focal length 10 cm are placed in close contact with one another.
(a) What is the power of this combination?
(b) What is the focal length of this combination?
(c) Is this combination converging or diverging?
A diverging lens has a focal length of 0.10 m. The power of this lens will be:
How does the power of a lens change if its focal length is doubled?
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 double convex lens has focal length 25 cm. The radius of curvature of one of the surfaces is double of the other. Find the radii, if the refractive index of the material of the lens is 1.5.
Consider the situation described in the previous problem. Where should a point source be placed on the principal axis so that the two images form at the same place?
One dioptre is the power of a lens whose focal length is:
A positive power of a lens indicates a:
