Question

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

Answer 1

Answer:

$\boxed{\sf Focal \ length = 10 \ cm}$

Given:

Radius of curvature (R) of a spherical mirror = 20

To Find:

Focal length (f)

Explanation:

Formula:

$\boxed{ \bold{\sf Focal \ length \ (f) = \frac{Radius \ of \ curvature \ (R)}{2}}}$

Substituting value of R in the equation:

$\sf \implies f = \frac{20}{2}$

$\sf \implies f = \frac{ \cancel{2} \times 10}{ \cancel{2}}$

$\sf \implies f = 10 \: cm$

Answer 2

Focal length = 10 cm.

Solution :

Given radius of curvature = 20 cm.

Formula :

Focal length = Radius of curvature/2

→ Focal length = 20/2

→ Focal length = 10 cm.

Answer : 10 cm.