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

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

1.	An object of size 7.0 cm is placed at 27 cm in front of a concave mirror of focal length 18 cm. At what distance from the mirror should a screen be placed, so that a sharp focussed image can be obtained?Find the size and the nature of the image.
Answer» SOLUTION :`h_(1)=7CM` `u=-27cm` `f=-18cm` `v=?` `h_(2)=?` `1/f=1/v+1/u` `v=(uf)/(u-f)` `=486/(-9)` `v=-54cm` `(h_(2))/(h_(1))=-v/u` `h_(2)=(-v)/uxxh_(1)` `=((-54)/(-27))xx7` `h_(2)=-14cm`