The pressure measuring device that is based on height difference of a liquid is called a:
a. Manometer b. Transducer c. Pressure gage d. All of the above.
The correct answer and explanation is:
The correct answer is a. Manometer.
A manometer is a pressure measuring device that relies on the height difference of a liquid column to measure pressure. This type of device works on the principle of hydrostatic pressure, which states that the pressure at a point in a fluid is directly proportional to the height of the liquid column and the density of the liquid. In a manometer, one end is open to the atmosphere or a reference pressure, and the other end is connected to the system whose pressure is being measured.
The liquid used in manometers is typically mercury or water, depending on the range of pressure to be measured. When a pressure is applied to the system, it causes the liquid in the manometer to rise or fall, depending on whether the pressure is greater or less than the reference pressure. The difference in the height of the liquid column is then used to calculate the pressure, using the formula P=ρghP = \rho g h, where PP is the pressure, ρ\rho is the density of the liquid, gg is the acceleration due to gravity, and hh is the height difference.
Manometers are commonly used in laboratories and industrial applications for measuring low to moderate pressures. They are relatively simple, cost-effective, and provide accurate results. However, they are less suitable for measuring high pressures, where more advanced devices, like pressure transducers, are typically used.
While transducers (option b) and pressure gauges (option c) are also devices used for measuring pressure, they operate differently. Transducers convert pressure into an electrical signal, and pressure gauges are mechanical devices that display pressure readings, often without relying on height differences of liquids. Hence, the manometer remains the correct answer.