Question 36General Subjects - QMED70% to pass
What is the operating principle of a variable area flow meter, such as a rotameter?
AI Explanation
The correct answer is B) The float or rotor is more dense than the fluid being measured and is positioned so that the gravitational force down is balanced by the upward motion of the fluid flow.
This is correct because in a variable area flow meter, such as a rotameter, the float or rotor is designed to be more dense than the fluid being measured. As the fluid flows upward through the tapered tube, the upward force of the fluid flow counteracts the downward gravitational force on the float, causing it to rise to a position where these forces are balanced. The position of the float or rotor within the tube indicates the flow rate of the fluid.
The other options are incorrect because they describe a scenario where the float or rotor is less dense than the fluid, which is not the operating principle of a rotameter.
Related Questions
#34 In what application would a reflex type flat gauge glass be used? #35 What statement best represents the characteristics of an innage tape and bob for the purposes of taking a vented tank sounding? #37 If a thermometer reads 80oC, what is the equivalent temperature in oF? #38 If the mercury has become separated in a liquid-in-glass thermometer, what can be done to correct this situation? #39 What type of direct reading thermometer works on the principle of differential expansion of dissimilar metals as the temperature rises and features a rotary dial scale?