Question

a concave mirror produces a real image of magnification 1/2,when an object is placed at a distance of 60cm from it.where the object should be placed so that a virtual image of double the size is formed by the mirror.

Answer 1

Given that,

Object distance u = –60 cm

then


⇒ V = 30 cm.

Now use mirror formula to find its focal length (f)


Again from question:-


Let object distance = –x


Then by using the mirror formula


Hence the required object distance = 120 cm