The radius of curvature of a spherical mirror is 20 cm. What is its focal length?

Radius of curvature (R) = 20 cm

Radius of curvature of the spherical mirror(R) = 2 × Focal length (f)

R = 2f

f= R/2 = 20 / 2 = 10 cm.

Therefore, the focal length of the spherical mirror is 10 cm