The magnification 'm' produced by a convex lens when the object is placed at a distance 2f from the lens is given by:

The correct answer is m = -1.Key Points

• When an object is placed at a distance of 2f from a convex lens, the image is formed at a distance of 2f on the other side of the lens.
• The image formed is real, inverted, and of the same size as the object.
• Magnification (m) = Height of Image / Height of Object = -1 (negative sign indicates inversion).
• This scenario is a standard case in lens formulas and ray diagrams of convex lenses.
• Thus, magnification 'm' = -1 for object placed at 2f in convex lens.

Additional Information

• Convex Lens (Converging Lens)
  • A convex lens is thicker at the center and converges parallel rays of light to a point called the focus.
  • It forms real and inverted images for object distances greater than focal length (f), and virtual, erect images when the object is within f.
• Magnification (m)
  • Magnification = v/u or Height of Image / Height of Object.
  • Positive magnification indicates an erect image, negative indicates an inverted image.
• Lens Formula
  • 1/f = 1/v - 1/u where f = focal length, v = image distance, u = object distance.
  • All distances are measured from the optical center of the lens.
• Applications of Convex Lens
  • Used in magnifying glasses, microscopes, cameras, and human eye correction.