An air flow rate of up to 1 m3/s at standard conditions is expected in a 0.25-m diameter duct. An orifice meter is used to measure the rate of flow. The manometer available to make the measurement has a maximum range of 300 mm of water. Determine the diameter of the orifice plate that should be used with D and D/2 pressure taps. Determine the head loss if the flow area at the vena contracta is 0.65 of the orifice diameter.