A concave mirror has radius of curvature of 40 cm. At what distance from the pole
of the mirror a parallel beam of light would be focused after reflection?

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Solution

The point where a parallel beam of light would be focused after reflection is known principle focus of the mirror. And, the distance of the that point from the pole of the mirror is known as focal length. Now, we know that the focal length is half the radius of curvature so, it will be 40cm / 2 = 20cm.

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A concave mirror has radius of curvature of 40 cm. At what distance from the poleof the mirror a parallel beam of light would be focused after reflection?

A concave mirror has radius of curvature of 40 cm. At what distance from the pole
of the mirror a parallel beam of light would be focused after reflection?