Advertisements
Advertisements
प्रश्न
How unit of power related to focal length of a lens?
Advertisements
उत्तर
Power is expressed as inverse of focal length, f (in metres).
`"Power (in Diopters) ="1/"Focal length (in metres)"`
APPEARS IN
संबंधित प्रश्न
Calculate the focal length of a corrective lens having power +2.5 D.
Find the focal length of a lens of power −2.0 D. What type of lens is this?
What can you see in a completely dark room? If you switch on an electric bulb in this dark room as a light source, explain how you could now see:
(a) the electric bulb
(b) a piece of white paper
What do you understand by the power of a lens? Name one factor on which the power of a lens depends.
State the condition for the following a ray passes undeviated through the lens .
The power of a lens is + 1.0 D is :
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 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?
How is accommodation produced?
Increase in the converging power of eye lens cause ‘hypermetropia'
