The focal length of a spherical mirror of radius of curvature 30 cm is:(a) 10 cm (b) 15 cm (c) 20 cm (d) 30 cm

Academic Physics NCERT Class 10

(b) 15 cm

Explanation

Given,

Radius of curvature = $r$ = 30 cm

To find = $f$ = Focal length

Solution

We know that the focal length of a spherical mirror is half of its radius of curvature.

Mathematically it is given as-

$f=\frac{1}{2}R$

Now, putting the given value we get-

$f=\frac{1}{2}\times 30$

$f=15cm$

Hence, the focal length of the spherical mirror will be 15cm.

Simply Easy Learning

Updated on: 10-Oct-2022

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