Answer:
h = 10 cm
Explanation:
The magnification produced by a mirror is given by :
[tex]m=\dfrac{h'}{h}[/tex]
h' is the image size and h is the object size
We have, h = 10 cm, m = +1
So,
[tex]m=\dfrac{h'}{h}\\\\h=\dfrac{10}{1}\\\\h=10\ cm[/tex]
So, the size off the object is same as that of the size of the image i.e. 10 cm.