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प्रश्न
State the condition for the following a lens has both its focal lengths equal .
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उत्तर
If a lens has both its focal length equal medium is same on either side of lens.
संबंधित प्रश्न
Find the focal length of a lens of power −2.0 D. What type of lens is this?
A lens has a focal length of, −10 cm. What is the power of the lens and what is its nature?
The focal length of a lens is +150 mm. What kind of lens is it and what is its power?
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.
Express the power (with sign) of a concave lens of focal length 20 cm.
How does focal length of a lens change when red light incident on it is replaced by violet light? Give reason for your answer.
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Show the formation of the image by the sphere.
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