Which sensor category would be used to measure water level?

• A. Pressure
• B. Flow
• C. Water level
• D. Location

Answer: (C)

When you want to know how high the water is in a tank or reservoir, you use a sensor that directly measures the height of the water surface. That category is water level sensors. They are designed to respond to the distance to the water surface or the surface itself, giving a direct reading of water height. Examples include ultrasonic or radar level sensors, float-based sensors, and capacitive level sensors.

Other options measure different quantities: a pressure sensor reads hydrostatic pressure, which can be converted to level only indirectly and depends on density and tank shape; a flow sensor measures how fast water moves through a pipe; a location sensor indicates position in space. Since the goal is to measure water height directly, the water level sensor category is the best fit.