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
(b) At 2f
Explanation
Since, the magnification of the image is negative, it means the nature of the image is real and inverted. Also, size of the image is equal to 1, it implies that the size of the image is equal to the size of the object.
Thus, the image of this nature and size is formed when the object is placed at $2f$.
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