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प्रश्न
The power of a lens is, −2 D. What is its focal length?
The power of a lens is –2 D. What is the focal length and nature of the lens?
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उत्तर
Power of a lens is given by:
Power of a lens (P) = `1/"focal length (f in meters)"`
`p=1/f`
`⇒f=1/p`
`⇒f=1/-2`
f = −0.5 m
Since the power of the lens is negative, the lens is a concave lens.
संबंधित प्रश्न
Calculate the focal length of a corrective lens having power +2D.
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1) Which lenses are used in her spectacles?
2) State the defect of vision Kavita is suffering from.
3) Find the focal length of the lenses used in her spectacles
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(a) the electric bulb
(b) a piece of white paper
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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
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A positive power of a lens indicates a:
A negative power of a lens indicates a:
A greater numerical value of the power of a lens means:
When a lens is placed in a liquid, the total power of the lens is:
For a lens immersed in a medium of refractive index \[n_1\], the power is related to the focal length by:
