Why this matters: Every NEET question on thermodynamics requires identifying the process type first. The mnemonic "I Am In Italy" — Isothermal: U stays, Adiabatic: Q quits, Isochoric: W waits, Isobaric: all play — gives the zero/constant quantity instantly. Once the process type is known, the correct formula for Q, W, and $\Delta U$ follows automatically.