(a) Explain what is meant by a virtual, magnified image.(b) 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.(c) Three convex lenses are available having focal lengths of 4 cm, 40 cm and 4 m respectively. Which one would you choose as a magnifying glass and why?
(a) A virtual image is an image formed by a lens/mirror that cannot be taken on a screen, and a magnified image implies that the size of the image formed is larger than the size of the object.
(b) When an object is placed between the focus $(F')$ and the optical centre $(C)$ of a convex lens, the image formed is virtual, erect and magnified.
The diagram given below, showing the position of the object and image with respect to the principal focus.
![](/assets/questions/media/158636-44418-1620572036.png)
(c) We will choose the lens with a focal length of 4 cm as a magnifying glass because it will produce the greatest magnification among all. (the smaller the focal length of a lens, the higher will be the magnification).
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