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

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(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

Vedclass · Accepted Answer

$\frac{f}{x}$

Vedclass · Answer

(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

Similar Questions

At what distance from a concave mirror of focal length $10 \, cm$ should an object be placed to get a magnification of $2$?

$A$ diminished virtual image can be formed only in

$A$ short linear object $O$ is placed on the principal axis of a convex mirror of focal length $f$ as shown in the figure. The ratio of transverse magnification to longitudinal magnification is

An object is placed in front of a spherical mirror, and a $2$ times magnified image is formed on a screen. Choose the $\text{CORRECT}$ option.

$A$ person wants a real image of his own,$3$ times enlarged. Where should he stand in front of a concave mirror of radius of curvature $30 \ cm$ (in $cm$)?

Vedclass Test Series

Exam Paper Generator

Online Exam Module