What is the distance between the pole and focus of a spherical mirror?

Correct option is C

The correct answer is (C) $$\frac{R}{2}$$​

The distance between the pole and the focus of a spherical mirror is called the focal length.
For both concave and convex mirrors, the focal length  is related to the radius of curvature  by the following formula:
​$$f = \frac{R}{2}$$​​
​
Where:
f is the focal length (the distance from the pole to the focus),
R is the radius of curvature (the distance from the pole to the center of curvature).

Thus, the distance between the pole and the focus is half the radius of curvature.