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प्रश्न
If a magnification of, –1 (minus 1) is obtained by using a converging lens, then the object has to be placed:
(a) within f
(b) at 2f
(c) beyond 2f
(d) at infinity
उत्तर
At 2f
When an object is placed at 2f, the size of the image formed will be equal to the size of the object. Therefore, we get a magnification of 1.
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संबंधित प्रश्न
An object of 10 cm is placed in front of a plane mirror. The height of image will be …………….
(a) 5 cm
(b) 15 cm
(c) 20 cm
(d) 10 cm
The height of the image formed by an object of height 10 cm placed in front of a plane mirror is __________.
(a) 5 cm
(b) 10 cm
(c) 15 cm
(d) 20 cm
Which one of these circumstances enables a concave mirror to be used as a shaving mirror?
Write down a formula for the magnification produced by a concave mirror.
in terms of object distance and image distance
Fill in the following blank with suitable word:
If the magnification has a plus sign, than image is ......... and.........
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
A small object is so placed in front of a convex lens of 5 cm focal length that a virtual image is formed at a distance of 25 cm. Find the magnification.
A convex lens produces a magnification of + 5. The object is placed:
(a) at focus
(b) between f and 2f
(c) at less than f
(d) beyond 2f
Magnification for the convex mirror is ______.
A negative sign in the value of magnification indicates that the image is ______.
