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

(A) For a concave mirror,the focal length is taken as $-f$.The distance of the object from the principal focus is $x$. Since the object is placed in f

Vedclass · Accepted Answer

$\frac{f}{x}$

Vedclass · Answer

(A) For a concave mirror,the focal length is taken as $-f$.The distance of the object from the principal focus is $x$. Since the object is placed in front of the mirror,the object distance $u = -(f + x)$.Using the mirror formula: $\frac{1}{v} + \frac{1}{u} = \frac{1}{f_{mirror}}$$\frac{1}{v} + \frac{1}{-(f+x)} = \frac{1}{-f}$$\frac{1}{v} = \frac{1}{f+x} - \frac{1}{f} = \frac{f - (f+x)}{f(f+x)} = \frac{-x}{f(f+x)}$$v = -\frac{f(f+x)}{x}$Magnification $m = -\frac{v}{u} = -\left( \frac{-\frac{f(f+x)}{x}}{-(f+x)} \right) = -\frac{f}{x}$The magnitude of magnification is $|m| = \frac{f}{x}$.

The focal length of a concave mirror is $f$ and the distance from the object to the principal focus is $x$. The magnification will be:

Similar Questions

The graph between $u$ and $v$ for a convex mirror is

$A$ concave mirror is used to focus the image of a flower on a nearby wall $120 \ cm$ from the flower. If a lateral magnification of $16$ is desired,the distance of the flower from the mirror should be $... \ cm$.

In the parallax method for the determination of the focal length of a concave mirror,the object should always be placed:

An object of length $6 \ cm$ is placed at a distance of $4f$ on the principal axis of a concave mirror of focal length $f$. The length of the image will be ......$cm$.

$A$ spherical mirror forms an erect image three times the linear size of the object. If the distance between the object and the image is $80 \, cm$,the focal length of the mirror is........ (in $, cm$)

Vedclass Test Series

Exam Paper Generator

Online Exam Module