In Fig. `AB` is the principal axis of original thin convex lens of `f = 25 cm`. It has been cut into two top part is placed at `(0, 0)` and object `O` is at `(-50 cm, 0)`.
If there were no cut, the object would have been at a height `0.5 cm` from principal axis `AB`.
As `(1)/(v) - (1)/(u) = (1)/(f)`
`(1)/(v) = (1)/(f) + (1)/(u) = (1)/(25) - (1)/(50) = (1)/(50) :. v = 50 cm`
Magnification, `mu = (v)/(u) = (50)/(-50) = -1`
Thus, the image would have been formed at `50 cm` from the pole on right side of lens and `0.5 cm` below the principal axis. Hence, w.r.t. the X-axis passing through the edge of the cut lens, the co-ordinates of the image are `(50 cm, -1 cm)`.
