A point object is between the Pole and Focus | vedclass

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(A) For a concave mirror,the mirror formula is given by $\frac{1}{v} + \frac{1}{u} = \frac{1}{f}$.Differentiating with respect to time $t$,we get $-\f

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away from mirror and increasing in magnitude

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(A) For a concave mirror,the mirror formula is given by $\frac{1}{v} + \frac{1}{u} = \frac{1}{f}$.Differentiating with respect to time $t$,we get $-\frac{1}{v^2} \frac{dv}{dt} - \frac{1}{u^2} \frac{du}{dt} = 0$.Thus,the velocity of the image $v_i = \frac{dv}{dt} = -(\frac{v}{u})^2 \frac{du}{dt}$.Here,the object is between the Pole $(P)$ and Focus $(F)$,so $u As the object moves away from the mirror,$u$ increases (becomes less negative),and the image also moves away from the mirror ($v$ increases).The magnification $m = \frac{v}{|u|} = \frac{f}{f-u}$. As $u$ increases towards $f$,the magnitude of $m$ increases rapidly.Since $v_i = -m^2 v_o$,and $m$ increases as the object moves away from the mirror,the magnitude of the image velocity $|v_i| = m^2 |v_o|$ increases.Therefore,the image moves away from the mirror with an increasing magnitude of velocity.

$A$ point object is between the Pole and Focus of a concave mirror,and moving away from the mirror with a constant speed. Then,the velocity of the image is:

Similar Questions

$A$ 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 $u < 0$.

$A$ convex mirror of focal length $10\,cm$ is shown in the figure. $A$ linear object $AB = 5\,cm$ is placed along the optical axis. Point $B$ is at a distance of $20\,cm$ from the pole of the mirror. Then,the size of the image of $AB$ will be:

$A$ concave shaving mirror has a radius of curvature of $35.0 \, cm$. It is positioned so that the upright image of a man's face is $2.5 \, \times$ the size of the face. How far is the mirror from the face in $cm$?

Assertion $(A):$ The relation among $u, v$ and $f$ for a spherical mirror is valid only for mirrors whose sizes are very small compared to their radii of curvature.
Reason $(R):$ The laws of reflection are strictly valid for plane surfaces but not for large spherical surfaces.

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

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