The image of an object formed by a mirror is real, inverted and is of magnification - 1. If the image is at the distance of 30 cm from the mirror.(i) Where is the object placed ?(ii) Find the position of the image object is now moved 20 cm towards the mirror.(iii) What is the nature of the image obtained ? Justify your answer with the help of ray diagram.

The image of an object formed by a mirror is real, inverted and is of

1.	The image of an object formed by a mirror is real, inverted and is of magnification - 1. If the image is at the distance of 30 cm from the mirror.(i) Where is the object placed ?(ii) Find the position of the image object is now moved 20 cm towards the mirror.(iii) What is the nature of the image obtained ? Justify your answer with the help of ray diagram.
Answer» Solution :IMAGE of an object FORMED by a mirror is real, inverted indicates that the mirror is a CONCAVE mirror and that the image is formed on the same side as the object. (i) `m=-1 , v=-30 cm` `m =-(v)/(U)` `-l=-((-30)/(u)), u=-30` cm is the object distance (ii) Find focal length of the concave mirror using data from 1. `(1)/(v)=(1)/(u)=(1)/(f)` `(1)/((-30))+(1)/((-30))=(1)/(f), f=-15 cm` `u=-10 cm , f=-15 cm, v = ?` `(1)/(v)+(1)/(u)=(1)/(f)` `(1)/(v)+(1)/((-10))=(1)/((-15)), v = +30 cm` The + sign indicates that the image is formed behind the concave mirror (iii) `m=-(v)/(u)` `m=-((30)/(-10)), m = 3` The image is erect, virtual and enlarged