Convex Lens Ray Diagram Simulator

CBSE Board Exam Essentials: Ray Diagrams for Convex Lens

In Class 10 Board Exams, Ray Optics carries 7 to 10 marks. Students frequently lose marks due to incorrect arrow directions on rays, missing sign conventions, or confusing virtual images when the object is placed inside the focal length ($u < f$).

The 6 Standard Cases of Convex Lens Image Formation

• 1. At Infinity ($u = \infty$): Image at focus $F_2$, point-sized, real and inverted.
• 2. Beyond $2F_1$ ($u > 2f$): Image between $F_2$ and $2F_2$, diminished, real and inverted.
• 3. At $2F_1$ ($u = 2f$): Image at $2F_2$, exact same size ($m = -1$), real and inverted.
• 4. Between $F_1$ and $2F_1$ ($f < u < 2f$): Image beyond $2F_2$, enlarged ($|m| > 1$), real and inverted.
• 5. At $F_1$ ($u = f$): Image formed at infinity, highly magnified.
• 6. Between $F_1$ and Optical Center $O$ ($u < f$): Image on the same side as object, virtual, erect, and magnified (Simple Microscope principle!).

Sign Convention Rules (Cartesian System)

Remember: All distances are measured from the Optical Center $O$.
• Object distance ($u$) is always negative.
• Focal length ($f$) for a convex lens is always positive ($f > 0$).
• For real images, $v$ is positive and $m$ is negative.
• For virtual images, $v$ is negative and $m$ is positive.