What is the relation between the focal length and radius of curvature of a spherical mirror (concave mirror or convex mirror)? Calculate the focal length of a spherical mirror whose radius of curvature is 25cm.
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For a spherical mirror the principal focus (F) lies exactly mid-way between the pole (P) and centre of curvature (C). So, the focal length (f) of a spherical mirror is equal to half of its radius of curvature (R).$\text{f}=\frac{\text{R}}{2}$
R= 25cm (Given) f = ? We know that$\text{f}=\frac{\text{R}}{2}$
$=\frac{25}{2}$
$\text{f} = 12.5\text{cm}$
R= 25cm (Given) f = ? We know that$\text{f}=\frac{\text{R}}{2}$
$=\frac{25}{2}$
$\text{f} = 12.5\text{cm}$
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