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प्रश्न
A convex lens forms an inverted image of size same as that of the object which is placed at a distance 60 cm in front of the lens. Find: The position of image
उत्तर
A convex lens forms an inverted, real, and an image of the same size as the object when the object is placed at 2f, i.e. (u = 2f).
In such cases, the image is formed at the point which is double the focal length on the other side of the lens (2f2).
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संबंधित प्रश्न
To determine the approximate focal length of the given convex lens by focussing a distant object (say, a sign board), you try to focus the image of the object on a screen. The image you obtain on the screen is always
(a) erect and laterally inverted
(b) erect and diminished
(c) inverted and diminished
(d) virtual, inverted and diminished
Study the given ray diagrams and select the correct statement from the following:
(A) Device X is a concave mirror and device Y is a convex lens, whose focal lengths are 20 cm and 25 cm respectively.
(B) Device X is a convex lens and device Y is a concave mirror, whose focal lengths are 10 cm and 25 cm respectively.
(C) Device X is a concave lens and device Y is a convex mirror, whose focal lengths are 20 cm and 25 cm respectively.
(D) Device X is a convex lens and device Y is a concave mirror, whose focal lengths are 20 cm and 25 cm respectively.
For what position of an object a real, diminished image is formed by a convex lens?
A convex lens of focal length 8 cm forms a real image of the same size as the object. The distance between object and its image will be:
(a) 8 cm
(b) 16 cm
(c) 24 cm
(d) 32 cm
What kind of lens is used to correct
long-sightedness?
A convex lens is placed in water. Its focal length will ______.
In the following cases, where must an object be placed in front of a convex lens so that the image formed is at infinity?
A pin 2 cm long is placed 12 cm away from a convex lens at right angles to the principal axis. If the focal length of the lens is 20 cm, by scale drawing find the size of the image and its magnification.
State two applications of a convex lens.
State the position of object, position of image, nature of image when: Convex lens is used as in searchlight.
