A concave mirror has a focal length 20,cm. Th | vedclass

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

Question

(A) For a concave mirror,the magnification $m = -v/u$. Given $|m| = 2$,so $v/u = 2$ or $v/u = -2$.Case $1$: $v = 2u$. Using the mirror formula $1/v +

Vedclass · Accepted Answer

$20$

Vedclass · Answer

(A) For a concave mirror,the magnification $m = -v/u$. Given $|m| = 2$,so $v/u = 2$ or $v/u = -2$.Case $1$: $v = 2u$. Using the mirror formula $1/v + 1/u = 1/f$ with $f = -20\,cm$:$1/(2u) + 1/u = -1/20 \implies 3/(2u) = -1/20 \implies u_1 = -30\,cm$.Case $2$: $v = -2u$. Using the mirror formula:$1/(-2u) + 1/u = -1/20 \implies 1/(2u) = -1/20 \implies u_2 = -10\,cm$.The distance between the two positions is $|u_1 - u_2| = |-30 - (-10)| = |-20| = 20\,cm$.

$A$ concave mirror has a focal length $20\,cm$. The distance between the two positions of the object for which the image size is double of the object size is......$cm$

Similar Questions

Which of the following graphs represents the magnification of a real image against the distance from the focus of a concave mirror?

An object is placed at the principal focus of a convex mirror. The image will be at

Consider a light source placed at a distance of $1.5 \ m$ along the axis facing the convex side of a spherical mirror of radius of curvature $1 \ m$. The position $(s^{\prime})$, nature and magnification $(m)$ of the image are

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

All of the following statements are correct except:

Vedclass Test Series

Exam Paper Generator

Online Exam Module