Question

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

Answer 1

The radius of curvature of a spherical mirror is 20 cm.
so,
f  =  R/2
  =20/2 =10cm
so,the focal length will be be 10cm

Answer 2

Answer:

The focal length of the spherical mirror is 10 cm

Given:

The 'radius' of 'curvature' of a 'spherical mirror' is 20 cm, r = 20

Explanation:

The focal length of a 'spherical mirror' is half of its 'radius of curvature.'

$f=\frac{r}{2} \rightarrow(1)$

Where f is the 'focal length', r is the 'radius' of curvature of a spherical mirror

Substituting the value of r in the above equation, we get

$\mathrm{f}=\frac{20}{2}=10 \mathrm{cm}$