For a plane mirror, the magnification (M = +1). What does this signify for (a) M=1 (b) positive sign of M?

Step 1: Signification of M =1,

1. A plane mirror is a mirror with a smooth flat reflective surface.
2. Magnification (M) of a mirror is defined as the ratio of the size of the image to the size of the object.
3. M = 1 indicates that the size of the image is equal to the size of the object.

Step 2: Signification of positive sign in M,

1. The positive sign of the magnification indicates that the image formed by a plane mirror is erect.