This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Anesthesia Machine, Subject name: Anaesthesia
[{'content': "Physical law made use in flow meter is:- \nSelect and explain. \nA. Henrys law, B. Grahams law, C. Daltons law, D. Faraday'slaw", 'role': 'user'}, {'content': "Answer: D \nExplanation: Velocity Flow Meters. Magnetic flow meters operate on Faraday'slaw of electromagnetic induction that states that a voltage is induced when a conductor moves through a magnetic field. The liquid serves as the conductor and the magnetic field is created by energized coils outside the flowtube.", 'role': 'assistant'}]