What is the Focal length of a convex mirror whose radius of curvature is 40 cm?.

The correct answer is 20 cm.

Key Points

• 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.

Important Points

Nature, position and relative size of the image formed by a convex mirror.