Pressure measurement is one of the most important parts of industrial instrumentation.
Whether it is pressure measurement in a pipeline, monitoring a boiler, or making sure equipment is safe, accurate pressure measurement is always needed.
Today, pressure devices are not just simple gauges; we now have advanced transmitters that give precise readings, compensate for errors, and even communicate digitally with control systems.
In our previous blog on Sensors and Transducers (Objective Questions & Answers), we shared useful MCQs that helped many learners and professionals strengthen their basics.
This time, we are focusing on Pressure Measurement with 75 advanced objective questions and answers. These will help engineers, technicians, and students refresh their knowledge, prepare for exams, and improve their practical understanding of pressure instruments.
So lets get started !
Pressure Measurements : Objective Questions and Answers
1. Which element is most commonly used in Bourdon tube pressure gauges?
a) Straight tube
b) Spiral tube
c) C-shaped tube
d) Diaphragm
Answer: c
2. Bourdon tube gauges are generally not suitable for:
a) High static pressures
b) Differential pressure measurement
c) Dynamic/vibrating pressure applications
d) Both b and c
Answer: d
3. A diaphragm pressure gauge measures pressure by detecting:
a) Resistance change in a wire
b) Voltage generated at junctions
c) Deflection of a thin membrane
d) Magnetic flux variation
Answer: c
4. A piezoelectric pressure sensor cannot measure:
a) Dynamic pressure
b) Transient pressure pulses
c) Steady-state static pressure
d) Impact forces
Answer: c
5. In strain gauge-based pressure transducers, the strain gauge is mounted on:
a) Bourdon tube tip
b) Diaphragm or pressure-sensitive element
c) A thermocouple junction
d) Magnetic core
Answer: b
6. Differential pressure transmitters are widely used in industry to measure:
a) Temperature difference
b) Flow rate across primary elements
c) Level in pressurized vessels
d) Both b and c
Answer: d
7. For orifice plate flow measurement, the relation between flow (Q) and differential pressure (ΔP) is:
a) Q∝ΔP
b) Q∝(ΔP)2
c) Q∝ sqrt{ΔP}
d) Independent of ΔP
Answer: c
8. The reference point for gauge pressure measurement is:
a) Perfect vacuum
b) Atmospheric pressure
c) Sealed reference cell
d) Absolute zero
Answer: b
9. Absolute pressure sensors measure pressure relative to:
a) Atmospheric pressure
b) Sealed reference at 1 bar
c) Perfect vacuum
d) Differential port
Answer: c
10. A manometer works on the principle of:
a) Pascal’s Law
b) Boyle’s Law
c) Hydrostatic Law
d) Charles’ Law
Answer: c
11. A U-tube manometer filled with mercury can measure:
a) Negative gauge pressures
b) Small pressure differences precisely
c) High static pressures in pipelines
d) Temperature variations indirectly
Answer: b
12. Capacitance-type pressure transducers work on the principle of:
a) Change in resistance with strain
b) Change in inductance with displacement
c) Change in capacitance due to diaphragm deflection
d) Voltage generation under compression
Answer: c
13. The main advantage of using a capacitance pressure sensor over piezoresistive type is:
a) No temperature sensitivity
b) Ability to measure absolute zero pressure
c) High sensitivity and low power consumption
d) Unlimited overload protection
Answer: c
14. A dead-weight tester is used for:
a) Level measurement
b) Flow calibration
c) Primary standard calibration of pressure instruments
d) Measuring absolute zero
Answer: c
15. Overpressure protection in pressure transmitters is usually provided by:
a) Adding external resistors
b) Special pressure relief diaphragms or stops
c) Insulating the case
d) Using a larger orifice
Answer: b
16. The most common material used for pressure transmitter diaphragms is:
a) Aluminum
b) Stainless steel
c) Brass
d) PVC
Answer: b
17. Remote diaphragm seals are used with pressure transmitters mainly to:
a) Reduce cost of installation
b) Avoid signal amplification
c) Protect the transmitter from corrosive or viscous media
d) Improve power supply stability
Answer: c
18. In differential pressure transmitters used for level measurement in closed tanks, the low-pressure port is connected to:
a) Atmosphere
b) Bottom of the tank
c) Top of the tank vapor space
d) Both top and bottom
Answer: c
19. The span of a pressure transmitter refers to:
a) Absolute zero
b) Difference between the upper and lower range values
c) Maximum possible over range
d) Calibration zero point
Answer: b
20. The most accurate laboratory pressure calibration device is:
a) Bourdon gauge
b) Manometer
c) Dead-weight tester
d) Spring gauge
Answer: c
21. The accuracy of a pressure gauge is generally expressed as a percentage of:
a) Zero error
b) Full-scale range
c) Span error only
d) Linearity error
Answer: b
22. A common error source in differential pressure transmitters measuring liquid flow is:
a) Lead wire resistance
b) Impulse line blockage or plugging
c) Magnetization of sensing element
d) Excessive vibration of casing
Answer: b
23. Which pressure transducer type is best suited for very low-pressure (vacuum) measurement?
a) Bourdon tube
b) Capacitive diaphragm sensor
c) Spring gauge
d) Piezoelectric sensor
Answer: b
24. A typical industrial pressure transmitter outputs:
a) 0–10 V DC
b) 24 V AC
c) 4–20 mA current signal
d) 0–1 kHz frequency
Answer: c
25. In HART-enabled smart pressure transmitters, digital communication is superimposed on:
a) Voltage signal
b) Analog 4–20 mA signal
c) AC mains
d) Fieldbus protocol
Answer: b
26. A vacuum gauge reads:
a) Pressure below atmospheric pressure
b) Absolute zero
c) Differential only
d) Gauge above atmosphere
Answer: a
27. Overpressure limit of a transmitter is typically:
a) Equal to 100% of full scale
b) 1.5 to 2 times the full-scale range
c) Infinite for all smart transmitters
d) Adjustable by the user
Answer: b
28. Which pressure unit is most commonly used in vacuum technology?
a) Pascal
b) psi
c) Torr (or mmHg)
d) bar
Answer: c
29. In a pressure transmitter, “zero elevation” refers to:
a) When the transmitter is mounted below the tapping point and requires positive biasing of zero
b) Overpressure compensation
c) Remote seal adjustment
d) Zero suppression due to high pressure
Answer: a
30. A resonant silicon pressure sensor works by measuring:
a) Strain resistance directly
b) Frequency shift in a vibrating element caused by applied pressure
c) Capacitance change in diaphragm
d) Piezoresistive coefficient change
Answer: b
31. Zero suppression in pressure transmitters is applied when:
a) Transmitter is above tapping point
b) Transmitter is below tapping point in open tank measurement
c) Transmitter has electrical interference
d) Transmitter diaphragm is damaged
Answer: b
32. Which of the following is used for very high-pressure measurement (>1000 bar)?
a) Bourdon tube
b) Manometer
c) Thick-walled diaphragm or wire strain gauge sensor
d) Dead-weight tester only
Answer: c
33. A bellows element is generally used in pressure instruments to measure:
a) Temperature
b) Flow
c) Low to medium pressures with good sensitivity
d) Level
Answer: c
34. The output of a piezoresistive pressure sensor is proportional to:
a) Capacitance
b) Frequency shift
c) Voltage generation
d) Change in resistance due to strain
Answer: d
35. Which of the following sensors can be used in high-temperature environments (>400 °C)?
a) Piezoresistive silicon sensor
b) Capacitive diaphragm sensor
c) Bourdon tube gauge
d) MEMS sensor
Answer: c
36. What is the primary error when impulse lines of a DP transmitter are not properly filled in liquid service?
a) Span shift
b) Zero shift
c) Hysteresis error
d) Linearity error
Answer: b
37. Remote seals in pressure transmitters are filled with:
a) Gas under pressure
b) Special fill fluids (like silicone oil) for hydraulic coupling
c) Water only
d) Air to transmit pressure
Answer: b
38. The most suitable pressure transducer for biomedical low-pressure applications (e.g., blood pressure) is:
a) Bourdon tube
b) Strain gauge
c) Capacitive or piezoresistive silicon diaphragm sensor
d) Manometer
Answer: c
39. Which device is used to measure extremely low absolute pressures (high vacuum)?
a) Bourdon tube
b) McLeod gauge or ionization gauge
c) U-tube manometer
d) Strain gauge transducer
Answer: b
40. A pressure transmitter accuracy specified as ±0.1% of span means:
a) ±0.1% of the measured value
b) ±0.1% of the calibrated range
c) ±0.1% of full-scale factory range
d) ±0.1% random noise
Answer: b
41. Dynamic pressure fluctuations in process lines are best measured by:
a) Bourdon gauge
b) Piezoelectric pressure transducer
c) Diaphragm seal
d) U-tube manometer
Answer: b
42. The primary cause of “drift” in a pressure transmitter over time is:
a) Blocked impulse lines
b) Aging of sensor materials and electronics
c) Overpressure damage only
d) Sudden vibration in pipework
Answer: b
43. Which type of transmitter can measure both positive and negative (vacuum) pressures?
a) Gauge pressure transmitter only
b) Differential pressure transmitter with atmospheric reference
c) Piezoelectric transducer
d) Capacitive absolute sensor
Answer: b
44. What is the purpose of a three-valve manifold in pressure transmitter installation?
a) Provide overvoltage protection
b) Allow isolation, equalization, and safe venting during calibration/maintenance
c) Reduce impulse line length
d) Provide redundancy
Answer: b
45. Pressure measurement in molten metal lines is best done using:
a) Bourdon gauge
b) Capacitance sensor
c) Diaphragm seal with high-temperature fill fluid
d) MEMS sensor
Answer: c
46. The maximum safe working pressure of a Bourdon tube gauge is limited by:
a) Tube temperature
b) Elastic limit of the tube material
c) Length of the capillary tube
d) Viscosity of fluid
Answer: b
47. A pressure transmitter with range 0–10 bar and accuracy ±0.2% of span can have a maximum error of:
a) ±0.02 bar
b) ±0.1 bar
c) ±0.2 bar
d) ±2 bar
Answer: c
48. Which device measures both static and dynamic pressure in aerodynamic testing?
a) Manometer
b) Pitot-static tube
c) Bourdon gauge
d) Piezoresistive sensor
Answer: b
49. The term “proof pressure” refers to:
a) Minimum measurable pressure
b) Maximum pressure that can be applied without causing permanent damage to a sensor
c) The rated full-scale range
d) Calibration error limit
Answer: b
50. Why are filled capillary systems used with remote-mounted pressure gauges?
a) To reduce accuracy
b) To isolate the gauge from high-temperature processes
c) To amplify pressure signal
d) To reduce cost of gauges
Answer: b
51. MEMS-based pressure sensors are typically made using:
a) Brass and copper
b) Micromachined silicon diaphragms with piezoresistive strain gauges
c) Thick metal plates
d) Optical fibers only
Answer: b
52. Which of the following is a secondary pressure standard?
a) Dead-weight tester
b) Calibrated Bourdon gauge
c) Mercury column manometer
d) Primary vacuum gauge
Answer: b
53. In high-pressure gas systems, which type of seal is used to prevent leaks around a diaphragm?
a) Rubber gasket
b) Welded or metallic seals
c) O-ring only
d) Plastic seal
Answer: b
54. Which error in pressure transmitters is caused by ambient temperature variation?
a) Linearity error
b) Span shift
c) Thermal drift
d) Hysteresis
Answer: c
55. In a DP transmitter used for flow, what happens if high- and low-pressure connections are accidentally reversed?
a) Span error
b) Output goes negative or reversed
c) No output
d) Hysteresis only
Answer: b
56. The unit “psi” stands for:
a) Pounds per square inch
b) Pounds-force per square inch
c) Pressure sensitivity index
d) Pounds per second
Answer: b
57. Which type of gauge has the fastest response time for fluctuating pressure?
a) Bourdon tube
b) Manometer
c) Piezoelectric transducer
d) Bellows
Answer: c
58. Absolute pressure measurement is essential in:
a) Boiler drum level
b) Vacuum systems and distillation columns
c) Open tank level
d) Atmospheric monitoring
Answer: b
59. What is the typical supply voltage for industrial pressure transmitters?
a) 5 V DC
b) 24 V DC
c) 110 V AC
d) 48 V DC
Answer: b
60. The damping feature in smart pressure transmitters is used to:
a) Increase sensitivity
b) Reduce hysteresis
c) Filter out process pressure fluctuations for stable output
d) Compensate zero shift
Answer: c
61. Which of the following is a primary pressure standard?
a) Dead-weight tester
b) Calibrated Bourdon gauge
c) Strain gauge transmitter
d) Manometer filled with air
Answer: a
62. Which device is used for very precise measurement of small differential pressures in clean labs?
a) Bourdon gauge
b) Inclined manometer
c) Piezoelectric sensor
d) Piston gauge
Answer: b
63. The pressure at the bottom of a liquid column is directly proportional to:
a) Temperature
b) Height of liquid column × density × gravity
c) Velocity of fluid
d) Viscosity of fluid
Answer: b
64. A piezoelectric crystal produces:
a) Constant current under pressure
b) Voltage proportional to applied dynamic pressure
c) Resistance variation only
d) Magnetic field distortion
Answer: b
65. Which of the following errors is NOT common in pressure measurement?
a) Zero drift
b) Span shift
c) Hysteresis
d) Refraction error
Answer: d
66. In a pressure transmitter, turndown ratio refers to:
a) Proof pressure / working pressure
b) Maximum span ÷ minimum adjustable span
c) Accuracy ÷ repeatability
d) Output ÷ input
Answer: b
67. Smart pressure transmitters perform internal corrections for:
a) Linearity
b) Temperature compensation
c) Zero/span errors
d) All of the above
Answer: d
68. Which pressure sensor type is most suitable for measuring rapid pressure transients in combustion chambers?
a) Bourdon gauge
b) Piezoelectric pressure sensor
c) Capacitance sensor
d) Diaphragm seal transmitter
Answer: b
69. Which fluid is most commonly used in dead-weight testers?
a) Water
b) Oil (hydraulic fluid)
c) Air
d) Mercury
Answer: b
70. An absolute pressure transmitter calibrated 0–1 bar abs will read what at vacuum (0 bar abs)?
a) 1 bar
b) 0 bar
c) –1 bar
d) 101.3 kPa
Answer: b
71. Which device is preferred for continuous furnace pressure measurement?
a) Manometer
b) Differential pressure transmitter
c) Dead-weight tester
d) Ionization gauge
Answer: b
72. The response time of a pressure sensor depends mainly on:
a) Sensor weight
b) Diaphragm stiffness and damping
c) Power supply
d) Capillary length only
Answer: b
73. Calibration frequency of pressure transmitters in process industries is usually decided by:
a) Manufacturer’s warranty
b) Industry standards and criticality of the measurement
c) Random operator choice
d) Local atmospheric pressure
Answer: b
74. The effect of altitude on a gauge pressure reading is:
a) No effect
b) Shift in zero reading due to lower atmospheric pressure
c) Span error
d) Hysteresis
Answer: b
75. Which of the following pressure measurement devices has the highest accuracy?
a) Bourdon tube gauge
b) Strain gauge transducer
c) Dead-weight tester (primary standard)
d) Diaphragm gauge
Answer: c
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