Advertisements
Advertisements
प्रश्न
Fill in the following blank with suitable words :
The reciprocal of the focal length in metres gives you the _________ of the lens, which is measured in ___________.
Advertisements
उत्तर
The reciprocal of the focal length in metres gives you the power of the lens, which is measured in dioptres.
संबंधित प्रश्न
What is meant by a power of a lens? Define its SI unit.
What does sign of power (+ve or –ve) indicate?
An object of height 4 cm is placed at a distance of 15 cm in front of a concave lens of power, −10 dioptres. Find the size of the image.
The power of a combination of two lenses X and Y is 5 D. If the focal length of lens X be 15 cm :
(a) calculate the focal length of lens Y.
(b) state the nature of lens Y.
A normal eye is not able to see objects closer than 25 cm because
A symmetric double convex lens is cut in two equal parts by a plane containing the principal axis. If the power of the original lens was 4 D, the power of a divided lens will be
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?
Consider the situation described in the previous problem. Where should a point source be placed on the principal axis so that the two images form at the same place?
The power of lens depends on the focal length of the lens
Increase in the converging power of eye lens cause ‘hypermetropia'
