Advertisements
Advertisements
प्रश्न
The power of a lens is +2.0 D. Find its focal length and state the kind of lens.
उत्तर
P = + 2.0 D
P = `1/("F" ("in meter"))`
`=> "F" = 1/ "P" = 1/2`
F = 0.5 m or 50 cm
∵ Power is (+ve)
∴ It is a convex lens.
APPEARS IN
संबंधित प्रश्न
Find the focal length of a lens of power −2.0 D. What type of lens is this?
Which one of the following materials cannot be used to make a lens?
Which type of lens has (a) a positive power, and (b) a negative power?
What do you understand by the power of a lens? Name one factor on which the power of a lens depends.
What is the unit of power of a lens? Define the unit of power of a lens.
On reducing the focal length of a lens, its power ______.
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
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 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.
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.
