Isochoric Process

Isochoric (or isovolumetric) process: volume stays CONSTANT (ΔV = 0).

No work done: W = P·ΔV = 0.

First law: Q = ΔU. All heat goes into internal energy.

Heat absorbed: Q = nC_v·ΔT.

On PV diagram: VERTICAL line.

Pressure-temperature link: P/T = constant (Gay-Lussac's law).

Examples: heating gas in a sealed rigid container, pressure cooker partially.

Used in Otto cycle (gasoline engine) — constant-volume heat addition (idealized).