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प्रश्न
Fill in the following blank with suitable word:
For converging lenses, the power is __________ while for diverging lenses, the power is ___________.
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उत्तर
For converging lenses, the power is positive while for diverging lenses, the power is negative.
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संबंधित प्रश्न
Calculate the focal length of a corrective lens having power +2D.
How unit of power related to focal length of a lens?
Consider two statements A and B given below:
A: real image is always inverted
B: virtual image is always erect
Out of these two statements:
Give the usual name for the following:
A point inside a lens through which the light passes undeviated.
What is the power of a convex lens of focal length 0.5 m?
What is the nature of a lens having a power of + 0.5 D?
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.
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.
A converging lens has a focal length of 50 cm. The power of this lens is:
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.
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.
A normal eye is not able to see objects closer than 25 cm because
A thin converging lens is formed with one surface convex and the other plane. Does the position of image depend on whether the convex surface or the plane surface faces the object?
Consider the situation described in the previous problem. Where should a point source be placed on the principal axis so that the two images form at the same place?
Which lens has more power a thick lens or a thin lens?
The power of the magnifying glass depends on the distance of the magnifying glass from object.
The above lens has a focal length of 10 cm. The object of height 2 mm is placed at a distance of 5 cm from the pole. Find the height of the image.
