Which of the following is an example of a flow meter which has associated with it a float for flow indication purposes?

Correct Answer: Option C — A variable volume flow meter (rotameter)

A rotameter, or variable area flow meter, consists of a tapered tube and a float. As fluid flows upward, the float rises to an equilibrium position where the upward force of the fluid balances the weight of the float, providing a direct visual indication of the flow rate.