Question

15. Magnification of a mirror is '--1What type of mirror is it? What is the position of
object and image? Give the nature of image
(2 mark)​

Answer 1

magnification m of a mirror =−vu=−imagedistanceobjectdistance

In our case m=−1

⇒−vu=−1⇒v=u

Object and image distances are same.

Further, in the magnification −1 , minus sign shows that the image is inverted and 1 shows that it is of the same size.

Thus this is a concave mirror and the object is placed at its centre of curvature.

One more thing, you can not say that the magnification of a mirror is -1 unless you specify the position of the object. Magnification of a mirror (except plane mirror) is different for different positions of the object.