A point object is placed at a distance of 10 | vedclass

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

Question

(A) For a concave mirror,the mirror formula is $\frac{1}{f} = \frac{1}{v} + \frac{1}{u}$.Given $u = -10 \ cm$ and $v = -20 \ cm$,we find the focal len

Vedclass · Accepted Answer

$0.4 \ cm$ away from the mirror

Vedclass · Answer

(A) For a concave mirror,the mirror formula is $\frac{1}{f} = \frac{1}{v} + \frac{1}{u}$.Given $u = -10 \ cm$ and $v = -20 \ cm$,we find the focal length $f$:$\frac{1}{f} = \frac{1}{-20} + \frac{1}{-10} = \frac{-1-2}{20} = -\frac{3}{20} \implies f = -\frac{20}{3} \ cm$.Differentiating the mirror formula with respect to $v$ and $u$:$-\frac{1}{v^2} dv - \frac{1}{u^2} du = 0 \implies \frac{dv}{du} = -\frac{v^2}{u^2}$.Here,$du = -0.1 \ cm$ (as the object moves towards the mirror).Substituting the values:$dv = -\left(\frac{-20}{-10}ight)^2 	imes (-0.1) = -(2)^2 	imes (-0.1) = -4 	imes (-0.1) = 0.4 \ cm$.The positive sign indicates that the image shifts away from the mirror.

$A$ point object is placed at a distance of $10 \ cm$ and its real image is formed at a distance of $20 \ cm$ from a concave mirror. If the object is moved by $0.1 \ cm$ towards the mirror,the image will shift by about:

Similar Questions

$A$ convex mirror of radius of curvature $30 \,cm$ forms an image that is half the size of the object. The object distance is: (in $\,cm$)

$A$ convex mirror of focal length $f$ is placed at the origin with its reflecting surface towards the negative $x-$ axis. Choose the correct graph between $v$ and $u$ for $u < 0$.

An object is placed $40\;cm$ from a concave mirror of focal length $20\;cm.$ The image formed is

$A$ convergent beam of light is incident on a convex mirror so as to converge to a distance $12 \, cm$ from the pole of the mirror. An inverted image of the same size is formed coincident with the virtual object. What is the focal length of the mirror? $(cm)$

An object is placed at $20 \ cm$ in front of a concave mirror,which produces a three times magnified real image. What is the focal length of the concave mirror (in $cm$)?

Vedclass Test Series

Exam Paper Generator

Online Exam Module