The focal length of a concave mirror is f and | vedclass

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(B) For a concave mirror,the magnification $m$ is given by $m = \frac{I}{O} = \frac{f}{f - u}$.Here,$u$ is the object distance from the pole. The dist

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$\frac{f}{x}$

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(B) For a concave mirror,the magnification $m$ is given by $m = \frac{I}{O} = \frac{f}{f - u}$.Here,$u$ is the object distance from the pole. The distance of the object from the principal focus is $x$.Since the object is placed in front of the mirror,the distance from the pole is $u = -(f + x)$.Substituting this into the magnification formula:$m = \frac{f}{f - (-(f + x))} = \frac{f}{f + f + x} = \frac{f}{2f + x}$.However,using Newton's form of the mirror equation,$x_1 x_2 = f^2$,where $x_1$ and $x_2$ are distances of object and image from the focus respectively.Here $x_1 = x$. So,$x_2 = \frac{f^2}{x}$.The magnification $m = \frac{f}{x_1} = \frac{f}{x}$ (magnitude).Thus,the ratio of the size of the image to the size of the object is $\frac{f}{x}$.

The focal length of a concave mirror is $f$ and the distance from the object to the principal focus is $x$. The ratio of the size of the image to the size of the object is

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