flow measurement venturimeter pilot tube orifice meter - Question Bank

1. Which of these devices is most sensitive to changes in flow rate for a given size?
A) Venturimeter
B) Orifice meter
C) Pitot tube
D) Flow nozzle
2. The theoretical discharge through an orifice is calculated using the pressure difference and the principle of:
A) Conservation of mass
B) Conservation of momentum
C) Bernoulli's equation
D) Torricelli's theorem
3. What is the main drawback of using a Pitot tube for flow measurement in a pipeline?
A) It measures average velocity
B) It requires a long straight run of pipe
C) It can only measure flow in open channels
D) It has a high discharge coefficient
4. For measuring the flow of highly viscous fluids, which device might be preferred due to lower head loss?
A) Orifice meter
B) Venturimeter
C) Pitot tube
D) Flow nozzle
5. The relationship between pressure and velocity in Bernoulli's principle is:
A) Directly proportional
B) Inversely proportional
C) Exponential
D) Logarithmic
6. Which of the following is a less common type of flow measurement device based on differential pressure?
A) Orifice plate
B) Venturimeter
C) Flow nozzle
D) Pitot tube
7. The stagnation point in a fluid flow is where the:
A) Velocity is maximum
B) Pressure is minimum
C) Velocity is zero
D) Density is maximum
8. The accuracy of an orifice meter is generally affected by:
A) The length of the pipe upstream
B) The presence of a vena contracta
C) The sharpness of the orifice edge
D) The fluid temperature
9. Which device measures flow rate by comparing the weight of the fluid displaced by a float?
A) Venturimeter
B) Orifice meter
C) Pitot tube
D) Rotameter
10. In a Venturimeter, the angle of the diverging section is typically kept small to:
A) Increase velocity
B) Minimize friction losses
C) Maximize pressure recovery
D) Reduce head loss
11. For accurate velocity measurement with a Pitot tube, the tube opening must be:
A) Aligned with the flow direction
B) Perpendicular to the flow direction
C) At a 45-degree angle to the flow
D) Rotated freely
12. The ratio of the area at the vena contracta to the area of the orifice is called the:
A) Discharge coefficient
B) Velocity coefficient
C) Contraction coefficient
D) Expansion coefficient
13. Which of the following is a type of differential pressure flow meter?
A) Pitot tube
B) Rotameter
C) Venturimeter
D) Anemometer
14. The flow rate through an orifice meter is calculated using the pressure difference between the upstream and the:
A) Throat
B) Vena contracta
C) Diverging section
D) Outlet of the pipe
15. A Pitot tube is unsuitable for measuring flow in:
A) Clean water pipelines
B) Air ducts
C) Pipelines with significant suspended solids
D) Gas streams
16. The discharge coefficient of a Venturimeter is relatively constant over a wide range of Reynolds numbers because:
A) The diverging section minimizes losses
B) The throat is very short
C) The converging section is long
D) The vena contracta is well-defined
17. If the fluid velocity increases, the dynamic pressure will:
A) Decrease
B) Increase
C) Remain constant
D) Become zero
18. What is the primary advantage of an orifice meter over a Venturimeter?
A) Lower cost and simpler construction
B) Higher accuracy
C) Lower head loss
D) Larger flow capacity
19. The 'vena contracta' effect is most pronounced in which flow measurement device?
A) Venturimeter
B) Pitot tube
C) Orifice meter
D) Flow nozzle
20. In a Rotameter, the float rises when:
A) Flow rate decreases
B) Fluid density increases
C) Flow rate increases
D) Tube diameter decreases
21. Which device measures flow rate by balancing gravitational forces with drag forces?
A) Venturimeter
B) Orifice meter
C) Rotameter
D) Pitot tube
22. The ratio of the actual discharge to the theoretical discharge through an orifice meter is known as the:
A) Velocity coefficient
B) Contraction coefficient
C) Discharge coefficient
D) Flow coefficient
23. A Pitot tube measures the difference between stagnation pressure and:
A) Dynamic pressure
B) Static pressure
C) Atmospheric pressure
D) Hydrostatic pressure
24. The primary application of a Venturimeter is for measuring:
A) Velocity at a point
B) Flow rate in pipes
C) Pressure difference
D) Fluid level
25. Which of the following is a type of orifice plate?
A) Concentric orifice
B) Spiral orifice
C) Annular orifice
D) Bellmouth orifice
26. The pressure tapping for a Pitot tube should ideally be placed:
A) In the turbulent wake of the flow
B) At the point of maximum velocity
C) Perpendicular to the flow direction
D) Parallel to the flow direction
27. For measuring the velocity of a high-speed aircraft, which instrument is commonly used?
A) Venturimeter
B) Orifice meter
C) Pitot tube
D) Weir
28. Which flow measurement device is most suitable for applications where minimal head loss is critical?
A) Orifice meter
B) Flow nozzle
C) Venturimeter
D) Rotameter
29. The vena contracta is the point where the fluid stream has:
A) Maximum area and minimum velocity
B) Minimum area and maximum velocity
C) Maximum area and maximum velocity
D) Minimum area and minimum velocity
30. Which factor significantly influences the discharge coefficient of an orifice meter?
A) Length of the pipe
B) Ratio of orifice diameter to pipe diameter
C) Fluid temperature
D) Atmospheric pressure
31. Compared to a Venturimeter, an orifice meter typically results in:
A) Lower head loss
B) Higher head loss
C) No head loss
D) Negligible head loss
32. The discharge coefficient for an orifice meter is generally:
A) Higher than that of a Venturimeter
B) Lower than that of a Venturimeter
C) Equal to that of a Venturimeter
D) Approximately 1.0
33. In an orifice meter, the point of maximum velocity and minimum pressure occurs at the:
A) Upstream of the orifice plate
B) At the orifice plate itself
C) The vena contracta
D) Downstream of the vena contracta
34. An orifice meter consists of a plate with an opening inserted in a pipeline, and it creates a:
A) Gradual increase in pressure
B) Sudden decrease in pressure
C) Pressure drop due to restriction
D) Constant flow rate
35. The orifice meter is a device used for:
A) Measuring fluid temperature
B) Measuring fluid viscosity
C) Measuring fluid flow rate
D) Measuring fluid density
36. A Pitot tube is most accurate when the flow is:
A) Highly turbulent
B) Stratified
C) Laminar and uniform
D) Multiphase
37. What is a significant limitation of using a Pitot tube?
A) It can only be used for gases
B) It measures average velocity over an area
C) It is prone to clogging in fluids with suspended solids
D) It causes significant head loss
38. The velocity of a fluid at a point using a Pitot tube is given by the formula:
A) sqrt(2 * (P_stagnation - P_static) / rho)
B) sqrt(2 * (P_static - P_stagnation) / rho)
C) (P_stagnation - P_static) / rho
D) sqrt(2 * rho * (P_stagnation - P_static))
39. The stagnation pressure measured by a Pitot tube is equal to the sum of:
A) Static pressure and kinetic energy per unit volume
B) Static pressure and potential energy per unit volume
C) Dynamic pressure and potential energy per unit volume
D) Static pressure and density
40. A Pitot tube measures the velocity of a fluid by determining the difference between:
A) Static pressure and dynamic pressure
B) Static pressure and total pressure
C) Dynamic pressure and total pressure
D) Stagnation pressure and static pressure
41. A Pitot tube is primarily used to measure:
A) Static pressure
B) Flow rate
C) Velocity at a point
D) Total pressure
42. For a Venturimeter, the flow rate is proportional to the square root of the:
A) Pressure difference between inlet and throat
B) Velocity at the throat
C) Density of the fluid
D) Diameter of the throat
43. What is the purpose of the diverging section in a Venturimeter?
A) To further decrease velocity
B) To increase pressure and recover kinetic energy
C) To create turbulence
D) To measure static pressure
44. The discharge coefficient for a Venturimeter is typically:
A) Less than 0.5
B) Between 0.95 and 0.99
C) Between 0.6 and 0.7
D) Close to 1.0
45. What is the main advantage of using a Venturimeter for flow measurement?
A) Low cost
B) Simple installation
C) Low head loss
D) High accuracy for turbulent flow only
46. According to Bernoulli's principle, as the velocity of a fluid increases, its:
A) Pressure increases
B) Pressure decreases
C) Density increases
D) Viscosity increases
47. In a Venturimeter, as the fluid flows from the wider section to the narrower throat, its velocity:
A) Decreases
B) Increases
C) Remains constant
D) Becomes turbulent
48. Which of the following is NOT a component of a standard Venturimeter?
A) Converging section
B) Throat
C) Diverging section
D) Measuring weir
49. What is the primary principle behind the operation of a Venturimeter?
A) Bernoulli's principle
B) Archimedes' principle
C) Pascal's law
D) Newton's third law