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प्रश्न
The lens of power + 1·0 D is ______.
पर्याय
Convex of focal length 1·0 cm
Convex of focal length 1·0 m
Concave of focal length 1·0 cm
Concave of focal length 1·0 m.
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उत्तर
The lens of power + 1·0 D is convex of focal length 1·0 m.
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संबंधित प्रश्न
Find the power of a concave lens of focal length 2m.
Name the physical quantity whose unit is dioptre.
Define power of a lens. Write its units. Deduce the relation `1/f =1/f_1 +1/f_2`for two thin lenses kept in contact coaxially.
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
Consider three converging lenses L1, L2 and L3 having identical geometrical construction. The index of refraction of L1 and L2 are \[\mu_1 \text{ and } \mu_2\] respectively. The upper half of the lens L3 has a refractive index \[\mu_1\] and the lower half has \[\mu_2\] following figure . A point object O is imaged at O1 by the lens L1 and at O2 by the lens L2placed in same position. If L3 is placed at the same place,
(a) there will be an image at O1
(b) there will be an image at O2.
(c) the only image will form somewhere between O1 and O2
(d) the only image will form away from O2.
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?
A stick partly immersed in water appears to be bent. Draw a ray diagram to show the bending of the stick when placed in water and viewed obliquely from above.
A point object is placed at O in front of a glass sphere as shown in figure.
Show the formation of the image by the sphere.
An object is kept at a distance of 1m from a lens of power +2D:
- Identify the type of lens.
- Calculate its focal length and distance of the image formed.
A lens has a power of \[+2\,D\]. Its focal length is:
