A pin of length 2.0 cm lies along the principal axis of a converging lens, the center being at a distance of 11 cm from the lens. The focal length of the lens is 6 cm. Find the size of the image.
Given,
The focal length of the lens, f= 6cm
Length of the pin AB = 2cm
The distance of pin from its center to the lens, u= 10cm
Now, according to the ray diagram, we can say that the pin is lying horizontally on the principal axis. The length of the pin is AB and the image formed by the lens of the pin will be A’B’
Using lens formula,
Similarly, for point B
Hence, the length of the image= 
1