Computer Applications

A point light source is kept in front of a convex mirror at a distance of 40 cm. The focal length of the mirror is 40 cm. Find the position of image.

Reflection of Light

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Answer

Given,

u = 40 cm (negative)

f = 40 cm (positive)

Mirror formula:

$\dfrac{1}{u} + \dfrac{1}{v} = \dfrac{1}{f}$

Substituting the values in the formula above, we get,

$- \dfrac{1}{40} + \dfrac{1}{v} = \dfrac{1}{40} \\[0.5em] \dfrac{1}{v} = \dfrac{1}{40} + \dfrac{1}{40} \\[0.5em] \dfrac{1}{v} = \dfrac{1+1}{40} \\[0.5em] \dfrac{1}{v} = \dfrac{2}{40} \\[0.5em] \dfrac{1}{v} = \dfrac{1}{20} \\[0.5em] \Rightarrow v = 20 \text{ cm} \\[0.5em]$

Hence, the image is formed 20 cm behind the mirror.

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Computer Applications

A point light source is kept in front of a convex mirror at a distance of 40 cm. The focal length of the mirror is 40 cm. Find the position of image.

Reflection of Light

Answer

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