Question

find the position of an object which when placed in front of convex mirror of focal length 20cm produces a virtual image which is half the size of objects.

Answer 1

This one is easy forsooth!Here we have,U(object distance) = -20cmF(focal length) =+25cmNow we will apply the mirror formula ie1/f=1/v+1/u1/25=-1/20+1/v1/25+1/20=1/vLcm(25,20) is 1004+5/100=1/v9/100=1/vV=100/9V=11.111cmPosition of the image is behind the mirror(11.111cm) and the image is diminished in nature.