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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 does sign of power (+ve or –ve) indicate?
Define 1 dioptre of power of a lens.
A convex lens forms a real and inverted image of a needle at a distance of 50 cm from it. Where is the needle placed in front of the convex lens if the image is equal to the size of the object? Also, find the power of the lens.
Kavita from 10th is using spectacles. The power of the lenses in her spectacles is –2.5 dioptre. Answer the following questions:
1) Which lenses are used in her spectacles?
2) State the defect of vision Kavita is suffering from.
3) Find the focal length of the lenses used in her spectacles
The power of a lens is + 0.2 D. Calculate its focal length.
What is the nature of a lens having a power of + 0.5 D?
Fill in the following blank with suitable word:
For converging lenses, the power is __________ while for diverging lenses, the power is ___________.
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 convex lens produces a double size real image when an object is placed at a distance of 18 cm from it. Where should the object be placed to produce a triple size real image?
According to Rayleigh’s scattering law, the amount of scattering of light is inversely proportional to the fourth power of its ______.
