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प्रश्न
What is meant by magnification? Write its expression. What is its sign for real image and virtual image?
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उत्तर
Magnification produced by a spherical mirror gives how many times the image of an object is magnified with respect to the object size.
It can be defined as the ratio of the height of the image (hi) to the height of the object (ho).
Magnification = m = `"hi"/"ho"= "height of the image"/"height of the object"`
- for real image it is negative,
- for virtual image it is positive.
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संबंधित प्रश्न
For which positions of the object does a concave mirror produce an inverted, magnified an real image?
The image formed by a concave mirror is virtual, erect and magnified. The position of object is:
(a) at focus
(b) between focus and centre of curvature
(c) at pole
(d) between pole and focus
What is the nature of image formed by a concave mirror if the magnification produced by the mirror
+4
When an object is placed 20 cm from a concave mirror, a real image magnified three times is formed. Find:
(a) the focal length of the mirror.
(b) Where must the object be placed to give a virtual images three times the height of the object?
A virtual, erect and magnified image of an object is to be obtained with a convex lens. For this purpose,the object should be placed:
(a) between 2F and infinity
(b) between F and optical centre
(c) between F and 2F
(d) at F
At what distance should an object be placed from a convex lens of focal length 18 cm to obtain an image at 24 cm from it on the other side? What will be the magnification produced in this case?
Linear magnification produced by a convex lens can be ______.
In order to obtain a magnification of, –3 (minus 3) with a convex lens, the object should be placed:
(a) between optical centre and F
(b) between F and 2F
(c) at 2F
(d) beyond 2F
A convex mirror has a focal length of 18 cm. The image of an object kept in front of the mirror is half the height of the object. What is the distance of the object from the mirror?
An object of height 7 cm is kept at a distance of 25 cm in front of a concave mirror. The focal length of the mirror is 15 cm. At what distance from the mirror should a screen be kept so as to get a clear image? What will be the size and nature of the image?
