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Question
A convex lens has a focal length of 10 cm. At which of the following position should an object be placed so that this convex lens may act as a magnifying glass?
(a) 15 cm
(b) 7 cm
(c) 20 cm
(d) 25 cm
Solution
7 cm,
since the image of an object placed between the focus and the optical centre of a convex lens is enlarged and virtual.
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