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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 ___________.
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उत्तर
The reciprocal of the focal length in metres gives you the power of the lens, which is measured in dioptres.
संबंधित प्रश्न
Calculate the focal length of a corrective lens having power +2.5 D.
What is meant by a power of a lens? Define its SI unit.
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.
Two lenses A and B have focal lengths of +20 cm and, −10 cm, respectively.
(a) What is the nature of lens A and lens B?
(b) What is the power of lens A and lens B?
(c) What is the power of combination if lenses A and B are held close together?
A diverging lens has a focal length of 0.10 m. The power of this lens will be:
State the condition for the following a lens has both its focal lengths equal .
Express the power (with sign) of a concave lens of focal length 20 cm.
A lens forms an upright and diminished image of an object, irrespective of its position. What kind of lens is this? Draw an outline ray diagram to show the formation of the image. State the position and one more characteristic of the image.
Power of a lens is – 4D, then its focal length is
The power of lens depends on the focal length of the lens
