Which of the following represents Boyle's law?
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → \(V \propto \frac{1}{P}\) (at constant \(T\))
Boyle’s law says that for a fixed mass of gas kept at a constant temperature, the volume is inversely proportional to the pressure: doubling the pressure halves the volume, so \(PV\) stays constant.
Why the other options are incorrect
Option (1) \(V \propto T\) (at constant \(P\)) — Incorrect. This is Charles’s law: at constant pressure, volume grows with absolute temperature.
Option (3) \(P \propto T\) (at constant \(V\)) — Incorrect. This is Gay-Lussac’s law (the pressure law) for a gas in a closed, rigid vessel.
Option (4) \(V \propto n\) (at constant \(T\) and \(P\)) — Incorrect. This is Avogadro’s law: equal volumes of gases hold equal numbers of moles.