Question

A magnification of a mirror is -1. What kind of a mirror is it, also write the position, nature of the image.

Answer 1

1. According to the question, Magnification is -1.
2. We know, The formula for magnification(m) = $\frac{Heightofimage}{Heightofobject}$
3. The mirror must be a spherical mirror (concave mirror) as the magnification in a plane mirror is never -1 but always 1.
   
4. Also, a convex mirror always produces images smaller than the size of the object so its magnification is always less than 1. Hence it is a concave mirror.
5. Since the magnification is -1 so the image must be of the same size as that of the object.
6. Since the image size = object size
7. So the object must have been kept at the center of curvature of the spherical mirror.
8. Since the magnification is negative, the image is real, inverted, and can be obtained on the screen.