Joule-Thomson Effect Definition — FRCA Primary MCQ
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Correct answer: D — Gas cooling that occurs when a gas expands from high to low pressure through a throttle without exchange of heat or work
The Joule-Thomson effect: when a real (non-ideal) gas expands from high to low pressure through a valve/orifice (throttle) without exchanging heat with surroundings it cools (for most gases at room temperature). This explains: cooling of gas cylinders during rapid use / cryoprobe function / and the risk of regulator freezing with rapidly emptying cylinders.
Reference: Al-Shaikh Stacey 2019 Essentials of Anaesthetic Equipment