Chemical Engineering

Differential Pressure Measurements

Question 1
Marks : +2 | -2
Pass Ratio : 100%
A closed manometer is filled with 3 fluids first on the left leg with density 8 kg/m3 and length 10 cm, middle one with density 10 kg/m3 and height difference 5 cm more on right leg and the third on the right leg with density 15 kg/m3, what is the length of the third liquid?
1 cm
2 cm
3 cm
4 cm
Explanation:
Pressure on both legs should be equal, => 8*10 = 10*5 + 15*x, => x = 2 cm.
Question 2
Marks : +2 | -2
Pass Ratio : 100%
A U-tube manometer is open at one end and has a gas at the other end if the level of the mercury in both legs of the manometer is equal then what is the temperature of the gas?
1 Pa
1 Torr
1 mm Hg
1 atm
Explanation:
Since the level of mercury in both legs are equal, this means that pressure is equal on both ends, => pressure of gas = pressure of atmosphere = 1 atm.
Question 3
Marks : +2 | -2
Pass Ratio : 100%
A U-tube manometer is closed at both ends one end is vacuum and other end has a gas, if the difference in level of mercury is h = 10 mm, what is the pressure of gas?
1.33 Pa
1.45 Pa
1.56 Pa
1.75 Pa
Explanation:
Since the other end of the manometer has vacuum, this means the pressure of gas is equal to the difference in pressure of mercury in both ends, => Pressure of gas = d*g*h = 13.6*9.8*0.01 = 1.33 Pa.
Question 4
Marks : +2 | -2
Pass Ratio : 100%
Which of the following device is used to measure the velocity of flow?
Manometer
Venturi meter
Pitot tube
None of the mentioned
Explanation:
Pitot tube is used to measure the velocity of flow.
Question 5
Marks : +2 | -2
Pass Ratio : 100%
What is the difference between manometer and differential manometer?
Differential manometer has gas in empty space
Manometer has gas in empty space
Differential manometer has liquid in empty space
Manometer has liquid in empty space
Explanation:
Differential manometer has gas in empty space while manometer has a vacuum.
Question 6
Marks : +2 | -2
Pass Ratio : 100%
Which of the following is used for the pressure measurement of only liquid?
Manometer
Piezometer
Differential Manometer
None of the mentioned
Explanation:
Piezometer is a pressure measuring device used to measure the pressure of liquid only.
Question 7
Marks : +2 | -2
Pass Ratio : 100%
A closed U-tube manometer has a gas on one end with pressure 10 Pa and other end has vacuum, what is the approximate density of the liquid if the height difference of the liquid is 10 cm?
1 Kg/m3
10 Kg/m3
100 Kg/m3
1000 Kg/m3
Explanation:
Pressure of gas = Pressure due to height difference of liquid = d*g*h, => 10 = d*10*0.1, => d = 10 Kg/m3.
Question 8
Marks : +2 | -2
Pass Ratio : 100%
A closed U-tube manometer has a gas on one end with pressure 5 Pa and other end has vacuum, what is the approximate height difference of the liquid if the density of liquid is 10 Kg/m3?
5 mm
10 mm
50 mm
100 mm
Explanation:
Pressure of gas = Pressure due to height difference of liquid = d*g*h, => 5 = 10*10*h => h = 0.05 m = 50 mm.
Question 9
Marks : +2 | -2
Pass Ratio : 100%
A barometer has liquid level 10 cm above the outside level and the gas captured inside has the pressure of 0.5 atm, what is the density of liquid?
0.5 atm-s2/m2
1 atm-s2/m2
1.5 atm-s2/m2
2 atm-s2/m2
Explanation:
Pressure of gas + Pressure of liquid = atmospheric pressure, => 0.5 atm + d*10*0.1 = 1 atm, => d = 0.5 atm-s2/m2.
Question 10
Marks : +2 | -2
Pass Ratio : 100%
Which of the following is used to measure a pressure of only gas?
U-tube manometer
Piezometer
Differential Manometer
None of the mentioned
Explanation:
U-tube manometer is used to measure the pressure of gas only.