GOKARAJURANGARAJU INSTITUTE OF ENGINEERING AND TECHNOLOGY

SENSORS MEASUREMENTS AND INSTRUMENTATION

Course Code: GR20A3092

UNIT-I: FUNDAMENTALS OF ELECTRICAL MEASUREMENTS

1. Explain the working principle of an ammeter. How is it different from that of a voltmeter?
2. Illustrate the internal construction and working of a permanent magnet moving coil
(PMMC) instrument when used as a voltmeter.
3. Describe the advantages and limitations of using a moving iron instrument as an ammeter.
4. What are the different methods of extending the range of an ammeter? Illustrate with
examples.
5. Explain the concept of a shunt in ammeters and how it affects the accuracy of the
measurement.
6. Compare and contrast the accuracy and sensitivity of PMMC and moving iron voltmeters.
7. How does the frequency of the measured signal affect the readings of PMMC and moving
iron instruments?
8. Interpret the role of damping in the operation of ammeters and voltmeters. Why is it
important?
9. Explain the term ‘burden’ in the context of current and voltage measurements using
ammeters and voltmeters.
10. Analyze the potential errors that can occur in ammeter and voltmeter readings and suggest
methods to minimize these errors.
11. Describe the construction and operation of a PMMC instrument. How is it calibrated?
12. What are the typical applications of moving iron instruments in electrical measurements?
13. Explain the torque equation of a PMMC instrument and how it influences the deflection.
14. Compare the linearity of the scale in PMMC and moving iron instruments. How does this
affect their usage?
15. Summarize the temperature effects on PMMC and moving iron instruments and how they
can be compensated.
16. Explain why PMMC instruments are not suitable for AC measurements while moving iron
instruments are.
17. Write a note on the hysteresis and eddy current losses in moving iron instruments. How do
they impact the measurement?
18. What are the constructional differences between attraction and repulsion type moving iron
instruments?
19. How does the spring control and gravity control affect the performance of PMMC and
moving iron instruments?
20. Illustrate the scale marking procedure for a PMMC instrument used as a voltmeter.
21. Explain the working principle of a current transformer (C.T.). How is it different from a
potential transformer (P.T.)?
22. Describe the constructional features of a potential transformer and its role in voltage
measurement.
23. What are the main sources of errors in current transformers? How can these errors be
minimized?
24. Outline the concept of burden in the context of C.T.s and P.T.s. How does it affect their
performance?
25. Explain the significance of the turn’s ratio in a current transformer and how it affects the
secondary current.
26. What is the phase angle error in a potential transformer? How does it impact the accuracy
of voltage measurements?
27. Compare the design considerations of a C.T. for metering purposes versus protection
purposes.
28. List the methods to compensate for the ratio errors in current and potential transformers.
29. Explain the importance of the accuracy class of C.T.s and P.T.s in electrical measurements.
30. How are C.T.s and P.T.s used in conjunction with other measuring instruments in power
systems?
31. Explain the working principle of a wattmeter. How does it measure electrical power in a
circuit?
32. Discuss the construction and operation of a dynamometer type wattmeter.
33. What are the different types of errors that can occur in a wattmeter? How can these errors
be minimized?
34. Describe the two-wattmeter method for measuring three-phase power. What are its
advantages and limitations?
 35. How is power measured in a single-phase circuit using a wattmeter? Illustrate with a
diagram.
36. Explain the concept of power factor. Why is it important in electrical power systems?
37. Describe how power factor can be measured using a power factor meter.
38. What are the effects of low power factor on the efficiency of power systems?
39. Discuss the methods to improve power factor in electrical systems.
40. Explain the relationship between power factor, active power, and reactive power in an AC
circuit.
41. What is active power? How is it different from reactive power and apparent power?
42. Describe the methods used for measuring active power in a three-phase system.
43. Explain how a wattmeter can be used to measure reactive power in an electrical circuit.
44. What is the use of a VAR meter for measuring reactive power.
45. How can the power triangle be used to understand the relationship between active, reactive,
and apparent power?
46. Explain the three-wattmeter method for measuring power in an unbalanced three-phase
system.
47. Describe the role of CTs and PTs in the measurement of power and power factor in high
voltage systems.
48. How does the phase angle between voltage and current affect the measurement of active
and reactive power?
49. Give the importance of accurate measurement of active and reactive power in power quality
analysis.
50. Explain how digital instruments and meters are used for measuring power and power factor
in modern electrical systems.

UNIT-II: MEASUREMENT OF ENERGY AND OTHER ELECTRICAL QUANTITIES

1. Explain the working principle of a single-phase induction type energy meter.

2. Outline the construction and operation of a three-phase energy meter.
3. What are the main components of an energy meter and their functions?
4. Describe the different types of errors that can occur in single-phase energy meters and how
they can be minimized.
5. How is the calibration of an energy meter carried out?
6. Compare and contrast electromechanical and electronic energy meters.
7. Explain how a three-phase energy meter measures power and energy in a balanced load
condition.
8. Give the concept of creeping in energy meters and how it can be prevented.
9. What are the advantages of using a static energy meter over an electromechanical energy
meter?
10. Explain the significance of the rotor in an induction type energy meter and how it
contributes to energy measurement.
11. How does a three-phase energy meter handle unbalanced loads?
12. Describe the role of a potential coil and current coil in the operation of an energy meter.
13. Explain the concept of power factor correction in the context of energy metering.
14. Give the importance of meter constant in energy meters.
15. Explain the principle of operation of an electronic energy meter and its advantages over
traditional meters.
16. Describe the working principle and applications of Crompton's potentiometer.
17. Explain the construction and operation of an AC potentiometer.
18. List the advantages of using an AC potentiometer over a DC potentiometer.
19. Explain how an AC potentiometer can be used to measure the magnitude and phase angle
of an unknown voltage.
20. Describe the process of standardization in Crompton's potentiometer.
21. What is the use of a potentiometer in calibrating voltmeters and ammeters.
22. Explain the principle of phase angle measurement using an AC potentiometer.
23. What are the sources of errors in potentiometric measurements and how can they be
minimized?
24. Describe the differences between a polar type and a coordinate type AC potentiometer.
25. How can a potentiometer be used to measure power in an AC circuit?
26. Explain the working principle of a Wheatstone bridge and its application in resistance
measurement.
27. Describe the construction and working of a Megger and its use in measuring insulation
resistance.
28. Illustrate the principle and operation of a Kelvin double bridge for low resistance
measurement.
29. Explain the procedure for measuring unknown resistance using a Wheatstone bridge.
30. What are the limitations of a Wheatstone bridge and how can they be overcome?
31. Describe the advantages of using a Kelvin double bridge over a Wheatstone bridge for low
resistance measurements.
32. Explain the factors affecting the accuracy of resistance measurements using a Megger.
33. What are the sources of error in a Kelvin double bridge and methods to minimize them.
34. Explain the significance of guard wires in high resistance measurements using a Megger.
35. How does temperature affect the measurement of resistance in bridges?
36. Describe the working principle of Maxwell’s bridge for measuring inductance.
37. Explain the construction and operation of Anderson’s bridge for inductance measurement.
38. Discuss the principle and working of Schering bridge for capacitance measurement.
39. Explain how an unknown inductance can be measured using Maxwell’s bridge.
40. Describe the advantages and limitations of Anderson’s bridge in inductance measurement.
41. Discuss the method of measuring capacitance using a Schering bridge.
42. Explain the sources of error in Maxwell’s bridge and how they can be minimized.
43. Describe the role of standard capacitors in the calibration of Schering bridge.
44. How can a Schering bridge be used to measure the dissipation factor of a capacitor?
45. Explain the importance of balancing conditions in bridge measurements of inductance and
capacitance.
46. Analyze the effect of frequency on the accuracy of measurements using Maxwell’s and
Schering bridges.
47. Describe the procedure for measuring the quality factor of an inductor using Anderson’s
bridge.
48. Explain the significance of the loss angle in the context of Schering bridge measurements.
49. How does stray capacitance and inductance affect the measurement accuracy of bridges?
50. Examine the practical applications of bridge methods in industrial and laboratory settings.
UNIT-III: OSCILLOSCOPE AND DIGITAL VOLTMETERS

1. Explain the working principle of a Cathode Ray Oscilloscope (CRO).

2. Describe the construction and function of the cathode ray tube (CRT) in a CRO.
3. What is the role of the electron gun in a CRO? How does it contribute to the display of
waveforms?
4. Explain how the intensity and focus controls affect the display on a CRO.
5. Describe the use of the graticule in a CRO for waveform analysis.
6. How is the triggering function used in a CRO to stabilize waveforms?
7. Explain the process of calibrating a CRO and why it is important.
8. How can a CRO be used to measure the rise time of a pulse waveform?
9. Explain the function of the time base generator in a CRO and how it affects the horizontal
sweep.
10. How does the time base control affect the horizontal scaling of a waveform?
11. Explain the importance of synchronization in the horizontal time base for accurate
waveform representation.
12. What is the impact of bandwidth on the performance of vertical amplifiers in a CRO.
13. Explain the concept of vertical position control and its significance in waveform analysis.
14. Describe the role of coupling (AC/DC) in vertical amplifiers and how it affects signal
display.
15. How can the vertical amplifier be used to measure small signal voltages accurately?
16. Elaborate the function of the X-Y mode in a CRO and its applications.
17. Explain how a CRO can be used to measure the phase difference between two waveforms.
18. Describe the method of measuring frequency using a CRO.
19. How can a dual trace CRO be used to compare the phase relationship between two signals?
20. Explain the importance of accurate triggering in phase and frequency measurements using
a CRO.
21. Describe the steps involved in calculating the frequency of a signal displayed on a CRO.
22. What are the limitations of using a CRO for phase measurement at high frequencies.
23. Explain the role of the time base in determining the accuracy of frequency measurements
on a CRO.
24. How can the phase shift be determined using the X-Y mode on a CRO?
25. Outline the significance of phase and frequency measurements in electrical signal analysis.
26. Explain the working principle of a sampling oscilloscope.
27. Describe how a sampling oscilloscope differs from a conventional CRO.
28. List the advantages of using a sampling oscilloscope for high-frequency signal
measurements.
29. Explain the concept of equivalent time sampling and its application in sampling
oscilloscopes.
30. What are the limitations of sampling oscilloscopes in terms of signal fidelity?
31. Describe how the sampling rate affects the accuracy of waveform reconstruction in a
sampling oscilloscope.
32. List the applications of sampling oscilloscopes in modern electronic testing.
33. Explain the process of aliasing in sampling oscilloscopes and how it can be minimized.
34. How does the input bandwidth of a sampling oscilloscope affect its performance?
35. What is the role of the sample and hold circuit in the operation of a sampling oscilloscope.
36. Explain the working principle of a digital storage oscilloscope (DSO).
37. Describe the differences between a DSO and an analog CRO.
38. List the advantages of using a DSO for signal analysis and storage.
39. Explain the concept of real-time sampling in a DSO and its significance.
40. How does a DSO store and display waveforms for later analysis?
41. Explain the importance of memory depth in a DSO for long-duration signal capture.
42. Describe the function of trigger modes in a DSO and their impact on waveform capture.
43. How can a DSO be used to analyze transient signals and glitches?
44. Explain the working principle of a digital voltmeter (DVM) using successive
approximation.
45. Describe the ramp method of voltage measurement in a DVM and its advantages.
46. Compare and contrast the successive approximation, ramp, and dual slope integration
methods used in DVMs.
47. Explain the advantages of using a dual slope integration DVM for low-frequency
measurements.
48. Describe the role of analog-to-digital converters (ADCs) in the operation of digital
voltmeters.
49. Explain the concept of auto-ranging in digital voltmeters and its benefits.
50. How does the sampling rate influence the performance of a digital voltmeter?

UNIT-IV: SENSOR FUNDAMENTAL PRINCIPLES

1. Define what a sensor is and explain its role in measurement systems.

2. List the different types of sensors based on their principles of operation.
3. Identify the key parameters that characterize the performance of a sensor.
4. Describe the basic working principle of a resistive sensor.
5. Name the different types of inductive sensors and their applications.
6. State the advantages of using capacitive sensors for displacement measurement.
7. Recall the principle of operation of a Linear Variable Differential Transformer (LVDT).
8. Enumerate the different classification criteria for sensors.
9. Outline the typical applications of force sensors in industry.
10. Mention the different types of transducers and how they convert physical quantities into
electrical signals.
11. Explain the concept of sensor sensitivity and its importance.
12. Discuss the differences between active and passive sensors with examples.
13. Summarize the working principle of inductive sensors.
14. Interpret the characteristics curve of a capacitive sensor.
15. Compare resistive and inductive sensors in terms of their applications and limitations.
16. Illustrate how a force sensor can be used in an automotive application.
17. Describe the factors that affect the accuracy of a position sensor.
18. Clarify how LVDTs are used to measure linear displacement.
19. Distinguish between mechanical and electro-mechanical sensors.
20. Explain how environmental conditions can impact sensor performance.
21. Demonstrate how to connect a resistive sensor to a measurement circuit.
22. Apply the concept of inductance to explain the operation of an inductive proximity sensor.
23. Use a capacitive sensor to measure the displacement of a moving object.
24. Show how force sensors can be integrated into a robotic arm for tactile feedback.
25. Implement an LVDT in a feedback system for precise control of a hydraulic actuator.
26. Measure the resistance change in a strain gauge sensor under varying loads.
27. Calculate the output voltage of a capacitive sensor given specific input parameters.
28. Operate an inductive sensor to detect the presence of a metal object.
29. Test the linearity of an LVDT by varying the position of the core.
30. Utilize a force sensor to measure the weight of an object in a laboratory experiment.
31. Analyze the error sources in resistive sensors and propose methods to minimize them.
32. Examine the frequency response of inductive sensors and its impact on dynamic
measurements.
33. Compare the performance characteristics of different types of capacitive sensors.
34. Investigate the hysteresis behavior in LVDTs and its effect on measurement accuracy.
35. Determine the sensitivity of a force sensor and how it influences the measurement range.
36. Evaluate the suitability of different position sensors for a given application.
37. Break down the signal conditioning requirements for inductive sensors.
38. Assess the temperature stability of resistive sensors and their calibration needs.
39. Interpret the data obtained from a capacitive sensor in a real-time monitoring system.
40. Critique the limitations of mechanical sensors compared to electro-mechanical sensors.
Synthesis
41. Design a measurement system using resistive sensors for strain measurement in a bridge
structure.
42. Formulate a method to enhance the accuracy of inductive sensors in proximity detection.
43. Develop a capacitive sensor-based system for measuring liquid level in a tank.
44. Construct a force measurement setup using multiple sensors for redundancy.
45. Propose an application where LVDTs can be used to improve system performance.
46. Create a calibration routine for a set of position sensors used in an industrial automation
system.
47. Devise a way to integrate mechanical and electro-mechanical sensors in a hybrid sensing
system.
48. Write a new type of sensor that combines the principles of capacitive and inductive sensing.
49. Plan an experiment to characterize the performance of different force sensors under varying
conditions.
50. Generate a report comparing the effectiveness of resistive, inductive, and capacitive
sensors in a specific application.

UNIT V: SENSOR APPLICATIONS

1. List the types of flow-rate sensors and their applications.

2. Define the working principle of a pressure sensor.
3. Identify the main components of a temperature sensor.
4. Name different types of ultrasonic sensors used in industry.
5. Recall the principle of operation of an acceleration sensor.
6. Enumerate the different types of pressure sensors.
7. State the uses of flow-rate sensors in process control.
8. Mention the common materials used in temperature sensors.
9. Describe the basic operation of an ultrasonic sensor.
10. Outline the applications of acceleration sensors in automotive systems.
11. Explain how a flow-rate sensor measures the velocity of a fluid.
12. Discuss the differences between absolute, gauge, and differential pressure sensors.
13. Summarize how thermocouples work to measure temperature.
14. Interpret the working principle of an ultrasonic sensor for distance measurement.
15. Compare piezoelectric and capacitive acceleration sensors.
16. Clarify how pressure sensors can be used to monitor fluid levels.
17. Illustrate the operation of a resistance temperature detector (RTD).
18. Explain the concept of time-of-flight in ultrasonic sensors.
19. Differentiate between analog and digital acceleration sensors.
20. Describe how flow-rate sensors are used in HVAC systems.
21. Demonstrate how to connect a flow-rate sensor to a data acquisition system.
22. Use a pressure sensor to measure the pressure in a hydraulic system.
23. Apply the principles of thermocouples to design a temperature monitoring system.
24. Show how an ultrasonic sensor can be used to detect obstacles in robotics.
25. Implement an acceleration sensor in a vibration monitoring system.
26. Measure the flow rate of water using a turbine flow sensor.
27. Operate a piezoelectric pressure sensor to monitor atmospheric pressure.
28. Install a thermistor in a circuit to measure temperature changes.
29. Test the accuracy of an ultrasonic distance sensor in various environments.
30. Calibrate an acceleration sensor for use in a motion capture system.
31. Analyze the error sources in flow-rate measurements and propose solutions.
32. Examine the factors affecting the accuracy of pressure sensors.
33. Compare the performance of thermocouples and RTDs in high-temperature environments.
34. Investigate the limitations of ultrasonic sensors in detecting transparent objects.
35. Determine the impact of temperature variations on the performance of acceleration sensors.
36. Evaluate the suitability of different flow-rate sensors for measuring gas flow.
37. Critique the design of a diaphragm pressure sensor.
38. Assess the response time of various temperature sensors.
39. Break down the signal processing requirements for ultrasonic sensors.
40. Interpret the data from an acceleration sensor used in structural health monitoring.
41. Judge the effectiveness of flow-rate sensors in energy management systems.
42. Appraise the reliability of piezoresistive pressure sensors in harsh environments.
43. Validate the accuracy of temperature measurements using thermocouples.
44. Review the performance of ultrasonic sensors in industrial automation.
45. Rank different types of acceleration sensors based on their sensitivity and range.
46. Critically evaluate the advantages and disadvantages of electromagnetic flow-rate sensors.
47. Assess the long-term stability of capacitive pressure sensors.
48. Examine the calibration methods for high-precision temperature sensors.
49. Defend the choice of ultrasonic sensors in automotive parking assistance systems.
50. Evaluate the impact of shock and vibration on the performance of MEMS acceleration
sensors.