PV Diagram Explorer
Switch between 4 processes on a single plot.
Key Notes
PV diagram: pressure (P) on y-axis vs volume (V) on x-axis. Represents thermodynamic processes graphically.
Each point: a specific state with P, V, T (and n) defined.
Each curve: a process. Slope and shape tell what kind of process.
Isothermal (PV = const): hyperbola.
Adiabatic (PV^γ = const): steeper than isothermal.
Isobaric: horizontal line.
Isochoric: vertical line.
Area under curve = work done by gas: W = ∫P·dV.
Cyclic process: closed loop on PV. Enclosed area = net work over cycle.
Formulas
Work done by gas (any process)
Area under the curve in PV diagram.
Cycle work
Net work in a complete cycle.
Isothermal work
Logarithmic.
Adiabatic work
Useful for gas processes without heat exchange.
Isobaric work
Constant P × ΔV.
Important Points
PV diagram visualizes thermodynamic processes — read off P, V, T at each point.
Area under curve = W. Sign matters: expansion (V increases) ⇒ positive W; compression ⇒ negative.
Cycles: clockwise = engine (positive W_net), counter-clockwise = refrigerator (negative W_net).
Isotherm < adiabat in slope: for same V change, P drops less in isotherm than adiabat.
ΔU = 0 along isotherm of ideal gas (only T fixed) — useful shortcut.
All four basic processes (isothermal, adiabatic, isobaric, isochoric) have distinct shapes on PV.
PV Diagram Explorer notes from sciphylab (also known as SciPhy, SciPhy Lab, SciPhy Labs, Physics Lab). Class 11 physics revision for JEE Mains, JEE Advanced, NEET UG, AP Physics 1/2/C, SAT, and CUET-UG.