Anaesthesia At a flow rate of 3L/min, inspiratory (FUO2) concentration of 30–60% can be achieved by using a – A Nasopharyngeal catheter B Simple face mask C Venturi mask D Head box 💡 Explanation At a flow rate of 3L/min, inspiratory (FUO2) concentration of 30–60% can be achieved by using a – ✓ Correct Answer: A. Nasopharyngeal catheter