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प्रश्न
Give the usual name for the following:
A point inside a lens through which the light passes undeviated.
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उत्तर
The usual name for a point inside a lens through which light passes undeviated is the optical center
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संबंधित प्रश्न
A doctor has prescribed a corrective lens of power +1.5 D. Find the focal length of the lens. Is the prescribed lens diverging or converging?
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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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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?
How is the sign (+ or -) of power of a lens related to its divergent or convergent action?
The power of a lens is + 1.0 D is :
Find the radius of curvature of the convex surface of a plano-convex lens, whose focal length is 0.3 m and the refractive index of the material of the lens is 1.5.
Consider three converging lenses L1, L2 and L3 having identical geometrical construction. The index of refraction of L1 and L2 are \[\mu_1 \text{ and } \mu_2\] respectively. The upper half of the lens L3 has a refractive index \[\mu_1\] and the lower half has \[\mu_2\] following figure . A point object O is imaged at O1 by the lens L1 and at O2 by the lens L2placed in same position. If L3 is placed at the same place,
(a) there will be an image at O1
(b) there will be an image at O2.
(c) the only image will form somewhere between O1 and O2
(d) the only image will form away from O2.
If there is a convex lens of focal length 75 cm and a concave lens of focal length 40 cm, then calculate their combined power and combined focal length.
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An object is placed in front of a converging lens. Obtain the conditions under which the magnification produced by the lens is
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An object is kept at a distance of 1m from a lens of power +2D:
- Identify the type of lens.
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