Lenses in contact (thin) (1/F = 1/f1 + 1/f2)
jee-mainjee-advancedneet-ug
1/F = 1/f1 + 1/f2
What each symbol means
| Symbol | What it stands for |
|---|---|
| F | Equivalent focal length of combined thin lenses in contact (m) |
| f_1 | Focal length of first lens (m) |
| f_2 | Focal length of second lens (m) |
When to use this
Standard JEE / NCERT assumptions unless stated (paraxial, thin lens, coherent YDSE sources, etc.).