| What is the operating principle of a variable area flow meter, such as a rotameter? |
| A) The float or rotor is less dense than the fluid being measured and is positioned so that the gravitational force up is balanced by the downward motion of the fluid flow. |
| 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. |
| C) The float or rotor is less 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. |
| D) The float or rotor is more dense than the fluid being measured and is positioned so that the gravitational force up is balanced by the downward motion of the fluid flow. |
