Question

If the focal length of a spherical mirror is 20 cm then its radius of curvature is​_______

Answer 1

Answer:

The radius of curvature of a spherical mirror is 20 cm. What is its focal length? Therefore, the focal length of the spherical mirror is 10 cm.

Answer 2

${ \red{ \bf{ Given: }}}$

Radius of curvature (R) = 20 cm

${ \red{ \bf{ Formula: }}}$

Radius of curvature of a spherical mirror = 2 — Focal length (f)

${ \red{ \bf{ Solution: }}}$

R= 2f

f= R/2

f = 20 / 2

f = 10

${ \red{ \bf{ Answer: }}}$

Hence, the focal length of the given spherical mirror is 10 cm

${ \red{ \bf{ Extra \: Information: }}}$

${ \green{ \bf{ What \: is \: radius \: of \: curvature? }}}$

The radius of a circle which touches a curve at a given point and has the same tangent and curvature at that point is called radius of curvature.

${ \green{ \bf{ What \: is \: its \: focal \: length? }}}$

the distance between the centre of a mirror or a lens and its focus is called focal length.