A mirror which can produce a magnification of +1 is
1) convex mirror 2) concave mirror 3) plane mirror 4)both concave &plane mirror
both concave and plane mirror
because plan mirror also show a image same size of object and in concave mirror objects placed at c then the image formed same size
because plan mirror also show a image same size of object and in concave mirror objects placed at c then the image formed same size