Lateral magnification (mirror) (m = −v/u)

jee-mainjee-advancedneet-ug

m = −v/u

What each symbol means

SymbolWhat it stands for
mLateral magnification (linear, signed)
uObject distance from pole (m)
vImage distance from pole (m)

When to use this

Standard JEE / NCERT assumptions unless stated (paraxial, thin lens, coherent YDSE sources, etc.).