Correct Answer - Option 1 : 20 cm
The correct answer is 20 cm.
- Given that,
- Radius of curvature= 40 cm.
- We know that the focal length of a spherical mirror is equal to half the radius of curvature of that mirror.
- \(Focal \ length = {Radius\ of\ curvature \over 2}\)
- \(Focal \ length = {40 \over 2}= 20\ cm\)
- Focal length for convex mirror whose 40 cm is 20 cm.
- A convex mirror is a spherical mirror whose reflecting surface is curved outwards.
- The centre of curvature of a convex mirror lies behind the mirror.
- Convex mirrors are mainly used as rear-view mirrors in vehicles.
Nature, position and relative size of the image formed by a convex mirror.
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Position of the Object
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Position of the image
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Size of the image
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Nature of the image
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At infinity
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At the focus F, behind the mirror
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Highly diminished, point-sized
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Virtual and erect
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Between infinity and the pole P of the mirror
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Between P and F, behind the mirror
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Diminished
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Virtual and erect
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