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प्रश्न
State power of a lens S.I. unit.
उत्तर
The S.I. unit of power is diopter (D).
संबंधित प्रश्न
Calculate the focal length of a corrective lens having power +2.5 D.
You have two lenses A and B of focal lengths +10 cm and –10 cm, respectively. State the nature and power of each lens. Which of the two lenses will form a virtual and magnified image of an object placed 8 cm from the lens? Draw a ray diagram to justify your answer
Which of the two has a greater power: a lens of short focal length or a lens of large focal length?
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.
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?
How is the sign (+ or -) of power of a lens related to its divergent or convergent action?
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.
Find the power of a convex lens of focal length of + 25 cm.
What is power of accommodation of eye?
An object is placed in front of a converging lens. Obtain the conditions under which the magnification produced by the lens is
- negative and
- positive.
