Name the point inside the lens through which a ray of light goes undeviated and draw the suitable ray diagram?
Answers
Explanation:
The point is known by a number of names.
In general, it is the Optical Center of the lens.
In a double convex lens, of equal curvatures, the label Lens Center is acceptable as well as the Geometric Center. It is also OK to call it the Intersection of the Diagonals of the Curved Kite (this is rarely used by physicists but masters of geometry like it because of symmetry); but because the LIMIT of the CURVATURE is a TRIANGULAR Prism, which would be to isosceles triangles sharing a common base, which a kite.
Some refer to it as the point of Zero Deviation. You refer to this in your question. This is true for thin lenses (vertical angle less that 6 degrees). In general, it is a “fuzzy” point and therefore not accurate.
Some math masters call it the Origin, because all distances (focal, image and object) are measured as displacements from it. This is acceptable because ray tracing is all geometry; or rather, analytical geometry.