An object is placed at a distance equal to 2f in front of a convex lens. Draw a labelled ray diagram to show the formation of image. State two characteristics of the image formed.

Explanation

i. A convex lens forms real, diminished and inverted image when an object is placed beyond `2F_(1)`.
ii. Consider an object AB shown in figure. A ray AO passing through optical centre goes undeviated as ray OA': Similarly, the ray AP, incident parallel to principal axis passes through focus `F_(2)` after refraction and meets the ray OA' at A'. This forms an image A'B'.
iii. This image is formed between `F_(2) and 2F_(2)`.