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प्रश्न
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.
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उत्तर
- Magnification is negative for the real image formed by a convex lens.
- Magnification is positive for the virtual image formed by a convex lens.
संबंधित प्रश्न
What is meant by a power of a lens? Define its SI unit.
Define 1 dioptre of power of a lens.
What is the nature of a lens whose power is, −4 D?
Mohan obtained a sharp inverted image of a distant tree on the screen placed behind the lens. He then moved the screen and tried to look through the lens in the direction of the object. He would see:
(1) a blurred image on the wall of the laboratory.
(2) an erect image of the tree on the lens.
(3) no image as the screen has been removed
(4) an inverted image of the tree at the focus of the lens.
A pin of length 2.00 cm is placed perpendicular to the principal axis of a converging lens. An inverted image of size 1.00 cm is formed at a distance of 40.0 cm from the pin. Find the focal length of the lens and its distance from the pin.
The power of the magnifying glass depends on the distance of the magnifying glass from object.
If focal length of a convex lens is 20 cm at what is the power of the lens?
According to Rayleigh’s scattering law, the amount of scattering of light is inversely proportional to the fourth power of its ______.
A convex lens with radii of curvature R1 = R2 is immersed in water. Assuming that the refractive indices of glass and water are 3/2 and 4/3 respectively, its focal length f1 in comparison to that in air, f, is ______.
The same size images are formed by a convex lens when the object is placed at 20 cm or at 10 cm from the lens. The focal length of convex lens is ______ cm.
