Question

formula is used to find the focal length of the mirror is a)f=uv/u+v b)f=uv/u-v c)f=v-u/uv d) f=uv/u+v​

Answer 1

Answer:

a) f=uv/u+v

I have kept the image attachment.

Hope u will get your answer.

Answer 2

Answer:

The formula used to calculate the focal length of a mirror is $f=\frac{uv}{u+v}$.

Explanation:

• A mirror's focal length is a gauge of its power.
• The focal length of the mirror is defined as the distance from the pole to the focus.
• When incident light rays are parallel to the primary axis, the focus is the point through which the reflected light rays pass (or appear to pass).
• The mirror formula is given as-

         $\frac{1}{f} =\frac{1}{u} +\frac{1}v}\\\frac{1}{f} =\frac{v+u}{uv}\\f =\frac{uv}{u+v}$

where, $f$ is the focal length, $u$ is the separation between an object and the mirror, and $v$ is the separation between an image and the mirror..

Hence, formula used for calculating the focal length of a mirror is  $f=\frac{uv}{u+v}$.

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