Answer:
D the difference between two pressures​
Explanation:
A manometer is a device used to measure the difference between the pressure in a place. Manometer is solely used to determine gas pressure.
- The device compares gas pressure to atmospheric pressure at any given point.
- It measures pressure against a fixed reference or with respect to a differential pressure in a place.
- The column of liquid is the medium it uses to measure the pressure differences.
- Pressure is the force exerted per unit area.
