Advertisements
Advertisements
प्रश्न
The focal length of a convex lens is 25 cm. What is its power?
उत्तर
Given, f = 25 cm
Power of a lens is given by:
Power (p)=1/f
`p=1/(25xx10^-2)=100/25=4.D`
APPEARS IN
संबंधित प्रश्न
(a) At what distance should the lens be held from the figure in order to view the squares distinctly with the maximum possible magnifying power?
(b) What is the magnification in this case?
(c) Is the magnification equal to the magnifying power in this case? Explain.
Which of the two has a greater power: a lens of short focal length or a lens of large focal length?
Which has more power : a thick convex lens or a thin convex lens, made of the same glass? Give reason for your choice.
A diverging lens has focal length of 3 cm. Calculate the power.
A screen is placed a distance 40 cm away from an illuminated object. A converging lens is placed between the source and the screen and its is attempted to form the image of the source on the screen. If no position could be found, the focal length of the lens
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?
Find the power of a convex lens of focal length of + 25 cm.
According to Rayleigh’s scattering law, the amount of scattering of light is inversely proportional to the fourth power of its ______.
When monochromatic red light is used instead of blue light in a convex lens, its focal length will ______.
The focal length of a double convex lens is equal to the radius of curvature of either surface. What is the refractive index of its material?
