1. A Closed U-tube manometer has a gas at one end and vacuum at other end, if the height difference of the liquid (density = 10 kg/m3) in the manometer in 5 cm, what is the pressure of the gas?
a) 10 N/m2
b) 5 N/m2
c) 2.5 N/m2
d) 1 N/m2
Explanation: Pressure of the gas = dgh = 10*10*0.05 = 5 N/m2.
2. Archimedes’ principle describes which of the following quantities?
a) Pressure
b) Buoyancy
c) Velocity
d) Mass
Explanation: Archimedes’ principle states that buoyant force on a body is equal to the weight of the body.
3. An object is dipped in water, if the weight of the object measured by spring balance is 10 g and buoyancy force acting on the object is 0.1 N then what is the actual mass of the object?
a) 10 g
b) 20 g
c) 30 g
d) 40 g
Explanation: Weight of the object = (10*10–3)*10 + 0.1 = 0.2 N, => actual mass of the object = 0.2/10 = 0.02 kg = 20 g.
4. An open end manometer is filled with a gas on one end and other end is open to atmosphere with height difference of liquid (density = 10000 Kg/m3) 10 cm, what is the pressure of gas?
a) 1 atm
b) 1.1 atm
c) 1.2 atm
d) 1.3 atm
Explanation: Pressure = 1 + 10000*10*0.1/101325 = 1.1 atm.
5. A closed end manometer is filled with a gas on one end and other end is close with vacuum, height difference of liquid (density = 10000 Kg/m3) 25 cm, what is the pressure of gas?
a) 0.1 atm
b) 0.24 atm
c) 0.36 atm
d) 0.9 atm
Explanation: Pressure = 10000*10*0.25/101325 = 0.24 atm.
6. Which of the following is used for the pressure measurement of only liquid?
a) Manometer
b) Piezometer
c) Differential Manometer
d) None of the mentioned
Explanation: Piezometer is a pressure measuring device used to measure the pressure of liquid only.
7. Which of the following is used to measure a pressure of only gas?
a) U-tube manometer
b) Piezometer
c) Differential Manometer
d) None of the mentioned
Explanation: U-tube manometer is used to measure the pressure of gas only
8. What is the difference between manometer and differential manometer?
a) Differential manometer has gas in empty space
b) Manometer has gas in empty space
c) Differential manometer has liquid in empty space
d) Manometer has liquid in empty space
Explanation: Differential manometer has gas in empty space while manometer has a vacuum.
9. Which of the following device is used to measure the velocity of flow?
a) Manometer
b) Venturi meter
c) Pitot tube
d) None of the mentioned
Explanation: Pitot tube is used to measure the velocity of flow
10. 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?
a) 1 Pa
b) 1 Torr
c) 1 mm Hg
d) 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.