Question:
(a) A tube from one end of a differential pressure transducer is placed at the bottom of a cylindrical cup (D= 0.8m, H= 0.1m) to measure mass flow rate.
The cup is filled with water (density= 998 kg/m3) and is draining through a small hole at the bottom of the cup. The pressure transducer has a sensitivity of 2mV/kpa and reads zero volts when the pressure difference is zero. What voltage is measured when the cup is half full?
(b) The diameter, length and resistance of a wire were measured to determine the resistivity of the material. Calculate the percent uncertainty in the resistivity based on a confidence level of 95%. Note Resistivity = (resistance* cross-sectional-area) / length.
(c) An inclined U-tube manometer filled with water(density= 998 kg/m3) is used to measure the pressure differential in a pilot-static tube placed in a wind tunnel. If the manometer is inclined at 45 degrees and the height difference along the incline is 0.062 m, what is the velocity of the air (density= 1.20kg/m3) in the wind tunnel?
(d) Which flow measuring device produces a smaller permanent pressure loss, an orifice plate or a venturi flow meter?
(e) A thermistor has a resistance of 20,000 ? at 100°C. Given the value of β = 3650°C, Ro = 20,000 Ω and R = 500 Ω. Evaluate the temperature corresponding to a thermistor resistance of 500 Ω.