A convex mirror is made from a section of the surface of a sphere of radius 10.0cm. Its principal focus is at a distance of from its pole.

Correct option is C

The correct answer is option (c) 5 cm

Given : 

Convex mirror

radius of curvature $R=10.0\text{cm}$  

Formula used :- ​For a convex mirror, the principal focus fff is related to the radius of curvature $R$ by the formula:

$$f=\frac{R}{2}$$

Solution :                                                       

$$f=\frac{10}{2}$$

          $$f=5 cm$$

Thus, the principal focus is at a distance of 5.0 cm from the pole.​​