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प्रश्न
Draw a ray diagram to show the formation of a virtual magnified image of an object by a convex lens. In your diagram, the position of object and image with respect to the principal focus should be shown clearly.
उत्तर
When an object is placed between the focus and the optical centre of a convex lens, the image formed is virtual and magnified as shown in the figure.
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संबंधित प्रश्न
An object of height 4 cm is placed at a distance of 20 cm from a concave lens of focal length 10 cm. Use lens formula to determine the position of the image formed.
A student has obtained a point image of a distant object using the given convex lens. To find the focal length of the lens he should measure the distance between the :
(A) lens and the object only
(B) lens and the screen only
(C) object and the image only
(D) lens and the object and also between the object and the image
An object is held 20 cm away from a converging lens of focal length 10 cm. Find the position of the image formed.
The image seen in a plane mirror cannot be formed on a screen. What name is given to this type of image?
In order to obtain a magnification of, −0.6 (minus 0.6) with a concave mirror, the object must be placed:
(a) at the focus
(b) between pole and focus
(c) between focus and centre of curvature
(d) beyond the centre of curvature
Explain what is meant by a virtual, magnified image.
What do you understand by the term magnification?
The lens of the eye is flattened when looking at nearby objects.
A lens of focal length 5 cm is being used by Debashree in the laboratory as a magnifying glass. Her least distance of distinct vision is 25 cm.
- What is the magnification obtained by using the glass?
- She keeps a book at a distance 10 cm from her eyes and tries to read. She is unable to read. What is the reason for this?