Question

the image formed by a convex mirror of focal length 30cm is a quarter of the object. what is the distance of the object from mirror​

Answer 1

distance of object from the mirror will be -30cm

it will placeat focus

so its image will formed oat the infinity

which is highly diminished.

Answer 2

m=1/4

m= -v/u

1/4=-v/u

u=-4v

by using mirror formula

1/30=1/v+1/-4v

1/30=3/4v

4v=90

ans u=-90 cm