Answer:
[tex] \boxed{\sf Focal \ length = 10 \ cm} [/tex]
Given:
Radius of curvature (R) of a spherical mirror = 20
To Find:
Focal length (f)
Explanation:
Formula:
[tex] \boxed{ \bold{\sf Focal \ length \ (f) = \frac{Radius \ of \ curvature \ (R)}{2}}}[/tex]
Substituting value of R in the equation:
[tex] \sf \implies f = \frac{20}{2} [/tex]
[tex] \sf \implies f = \frac{ \cancel{2} \times 10}{ \cancel{2}} [/tex]
[tex] \sf \implies f = 10 \: cm[/tex]
