Pitot Tube

Q. A venturimeter, having a diameter of 7.5 cm at the throat and 15 cm at the enlarged end, is installed in a horizontal pipeline of 15 cm diameter. The pipe carries an incompressible fluid at a steady rate of 30 litres per second. The difference of pressure head measured in terms of the moving fluid in between the enlarged and the throat of the venturimeter is observed to be 2.45 m. Taking the acceleration due to gravity as 9.81 m/s${}^2$, the coefficient of discharge of the venturimeter (correct up to two places of decimal) is

1. 0.95

Q. A pitot-static tube, with a coefficient of 0.98 is used to measure the velocity of water in a pipe. The stagnation pressure recorded is 3m and the static pressure is 0.5 m. What is the velocity of flow?

1. 7.2 m/s
2. 6.8 m/s
3. 5.9 m/s
4. 5.2 m/s

Q. A venturimeter of 20 mm throat diameter is used to measure the velocity of water in a horizontal pipe of 40 mm diameter. If the pressure difference between the pipe and throat sections is found to be 30 kPa then, neglecting frictional losses, the flow velocity is

1. 0.2 m/s
2. 1.0 m/s
3. 1.4 m/s
4. 2.0 m/s

Q. In an air flow the velocity is measured by a Pitot tube (coefficient = 1.0). The mass density of air can be taken as $1.2kg/m^3$. If the head difference in a vertical U-tube holding water is 12 mm, then what is the velocity of air in m/s?

1. 10
2. 14
3. 17
4. 20

Q. A U-tube manometer with a small quantity of mercury is used to measure the static pressure difference between two locations A and B in a conical section through which an incompressible fluid flows. At a particular flow rate, the mercury column appears as shown in the figure. The density of mercury is 13600 kg/$m^3$ and g = 9.81 $m/s^2$. Which of the following is correct?

1. Flow direction is A to B and $p_A-p_B=20kPa$
2. Flow direction is B to A and $p_A-p_B=1.4kPa$
3. Flow direction is A to B and $p_B-p_A=20kPa$
4. Flow direction is B to A and $p_B-p_A=1.4kPa$

Q. A venturimeter having a throat diameter of 0.1 m is used to estimate the flow rate of a horizontal pipe having a diameter of 0.2 m. For an observed pressure difference of 2 m of water head and coefficient of discharge equal to unity, assuming that the energy losses are negligible, the flow rate (in $m^3/s$) through the pipe is approximately equal to

1. 0.500
2. 0.150
3. 0.050
4. 0.015

Q. Figure shows the schematic for the measurement of velocity of air (density =1.2 kg/$m^3$) through a constant-area duct using a pitot tube and a water tube manometer. The differential head of water (density=1000 kg/$m^3$) in the two columns of the manometer is 10 mm. Take acceleration due to gravity as 9.8 m/$s^2$. The velocity of air in m/s is

1. 6.4
2. 9.0
   
3. 12.8
4. 25.6

Q. Water flows through a pipe of diameter 0.30 m. What would be the velocity V for the conditions shown in the figure below?

1. 1.084

Q. Flow measurements with a Prandtl-Pitot tube showed that the tip readings varied only across the flow while the side-opening readings varied only in the direction of flow. The type of flow is

1. Uniform irrotational
2. Uniform rotational
3. Non-uniform irrotational
4. Non-uniform rotational

Q. The arrangement shown in the figure measures the velocity V of a gas density
1 kg/$m^3$ flowing through a pipe. The acceleration due to gravity is 9.81 m/ $s^2$. If the manometric fluid is water (density 1000 kg/$m^3$) and the velocity V is 20 m/s, the differential head h (in mm) between the two arms of the manometer is____________

1. 20.4

Q. A prandtl tube (Pitot-static tube with C = 1) is used to measure the velocity of water. The differential manometer reading is 10 mm of liquid column with a relative density of 10. Assuming g = 9.8$m/s^2$, the velocity of water (in m/s) is ________

1. 1.328

Q. Water $\rho =1000kg/m^3$ flows through a venturimeter with inlet diameter 80 mm and throat diameter 40 mm. The inlet and throat gauge pressures are measured to be 400 kPa and 130 kPa respectively. Assuming the venturimeter to be horizontal and neglecting friction, the inlet velocity (in m/s) is______

1. 6

Q. A line source of strength $15\pi m/s$ is situated within a uniform stream flowing at -12 m/s (i.e. right to left). At a distance of 0.6 m downstream from the source is an equal sink. How far will the stagnation points be from the nearest source/sink?

1. 0.38 m
2. 0.46 m
3. 0.52 m
4. 0.58 m