Correct Answer:
B. A floating buoy that rises and falls with the liquid level, activating a switch to send an electrical signal to a control system.
Explanation:
- A. Incorrect: A weighted ball typically does not produce an electrical or digital output signal; it usually provides a direct mechanical action.
- B. Correct: A floating buoy or float switch moves with the liquid level and triggers an electrical switch when it reaches a certain point. This switch sends a signal to a remote control system, which can then adjust the liquid level by controlling pumps or valves.
- C. Incorrect: A submerged probe might measure pressure changes, but it is not a flotation device and does not directly control the liquid level through flotation.
- D. Incorrect: A rotating vane typically measures flow rate rather than liquid level and does not operate based on flotation principles.
Correct Answer:
B. A floating buoy that rises and falls with the liquid level, activating a switch to send an electrical signal to a control system.
Explanation:
- A. Incorrect: A weighted ball typically does not produce an electrical or digital output signal; it usually provides a direct mechanical action.
- B. Correct: A floating buoy or float switch moves with the liquid level and triggers an electrical switch when it reaches a certain point. This switch sends a signal to a remote control system, which can then adjust the liquid level by controlling pumps or valves.
- C. Incorrect: A submerged probe might measure pressure changes, but it is not a flotation device and does not directly control the liquid level through flotation.
- D. Incorrect: A rotating vane typically measures flow rate rather than liquid level and does not operate based on flotation principles.