An object of size 7.0cm is placed at 27cm is front of a concave mirror of focal length 18cm. At what distance from the mirror should a screen be placed, so that a sharp focused image can be obtained? Find the size and the nature of the image.

An object of size 7.0cm is placed at 27cm is front of a concave mirror

1.	An object of size 7.0cm is placed at 27cm is front of a concave mirror of focal length 18cm. At what distance from the mirror should a screen be placed, so that a sharp focused image can be obtained? Find the size and the nature of the image.
Answer» Solution :Object distance,u=-27cm Object height, h=7cm Focal length, f=-18cm According to the mirror FORMULA `1/v-1/u=1/f` `v=1/f-1/u` `(-1)/(18)+1/(27)=(-1)/(54)` `v=-54cm` The SCREEN should-be placed at a distance of 54 CM in front of the given mirror. Magnification, `m=("Image distance")/("Object distance")=(-54)/(27)=-2` The NEGATIVE value of magnification indicates that the image FORMED is real. Magnification, m`=("Height of the image")/("Height of the Object")=(h_1)/h` `h.=7xx(-2)=-14cm`