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प्रश्न
Power of a lens is – 4D, then its focal length is
पर्याय
4m
–40m
–0.25 m
–2.5 m
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उत्तर
– 0.25 m
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संबंधित प्रश्न
Define the power of a lens.
You have two lenses A and B of focal lengths +10 cm and –10 cm, respectively. State the nature and power of each lens. Which of the two lenses will form a virtual and magnified image of an object placed 8 cm from the lens? Draw a ray diagram to justify your answer
The lens A has a focal length of 25 cm whereas another lens B has a focal length of 60 cm. Giving reason state, which lens has more power: A or B.
What is the power of a convex lens of focal length 0.5 m?
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 ___________.
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.
An object of height 4.25 mm is placed at a distance of 10 cm from a convex lens of power +5D. Find (i) the focal length of the lens, and (ii) the size of the image.
If focal length of a convex lens is 20 cm at what is the power of the lens?
The power of lens depends on the focal length of the lens
