MEASUREMENTS AND INSTRUMENTATION-QB

B.E./B.Tech. DEGREE EXAMINATION, APRIL/MAY 2011
Third Semester
Electrical and Electronics Engineering
EE 2201 — MEASUREMENTS AND INSTRUMENTATION
(Regulation 2008)  Time : Three hours Maximum : 100 marks
Answer ALL questions
PART A — (10 × 2 = 20 marks)
1. Define dynamic characteristics of an instrument.
2. Write down the different Standards of an instrument.
3. State the purpose of Shunts in the Voltmeter.
4. Classify different types of iron loss.
5. List the application of A.C. bridge.
6. Enumerate the principle of grounding.
7. List any two storage devices.          
8. Differentiate the functions of printer and plotter.
9.Define transducer.
10. Give any two applications of Smart Sensors.
PART B — (5 × 16 = 80 marks)
11. (a) Describe the static and dynamic characteristics of measuring
instrument. (16)
Or
(b) (i) Explain the concept of static evaluation of measurement data. (8)
(ii) Describe the different calibration procedures of measuring
instrument. (8)         
12. (a) (i) With a neat block diagram, explain the construction and
operating principle of digital voltmeter. (8)
(ii) Describe the functional operation of energy meter. (8)
Or
(b) (i) Describe the basic magnetic measurement using B-H curve (8)
(ii) Explain the operating principle of instrument transformer. (8)
13. (a) (i) Describe the operation of A.C. potentiometer. (8)
(ii) With a neat bridge network, derive the general equation for
bridge balance with a neat a.c. bridge diagram. (8)
Or
(b) Explain the operation of Schering Bridge to determine the unknown
capacitance. Derive the relevant equations and explain the
computation procedure using phasor diagram. (16)
14. (a) Write brief notes on          
(i) Magnetic disk and tape
(ii) Recorders and printers. (8+8)
Or
(b) With a help of simplified block diagram, explain the construction and
operating principle of general purpose Cathode Ray Oscilloscope. (16)
15. (a) (i) Explain the measurement of resistance using strain gauge. (8)
(ii) Describe the various factors influencing the type of transducer
for a particular application. (8)        
Or
(b) Explain the principle of operation.
(ii) A/D converter.      
NOVEMBER /DECEMBER 2008
PART A
1.What is the importance of dynamic characteristics of systems?
2. Why must instruments be calibrated?
3. What are the advantages of digital instruments over analog instruments?
4. How are resisters and diodes checked using digital multimeters?
5.Derive the condition for sustained oscillation in feedback oscillators?
6. What is electromagnetic interference in instruments?
7. Write briefly in pink plotter.
8. Explain briefly on magnetic tapes.
9. how are stain gauge used for pressure measurement?
10. What is meant by quantization error?
PART B
11 (a) (i) Explain on the static and dynamic characteristics of a measurement system.
          (ii) If a set of six observations are as follows:
           1.5V,3V,1V,5V,2V,4V.
Calculate the arithmetic mean, average deviation and standard deviation.(10+6)
Or
(b) With a neat figure explain briefly on each the building blocks of a digital display instrument . Write briefly seven segment LED display decoder. (10+6)
12. (a) (i) Write briefly on the various torque in analog indicating instruments.
(ii) With neat figures explain how frequency of a signal is measured using a CRO. (6+10)
Or
(b) Write briefly with neat figures on
(i) Principle of operation of a current transformer.
(ii) B.H. curve analysis of magnetic circuit.(10+6)
13. (a) (i) Derive the bridge balance condition for the Maxwell bridge and Schering bridge.
(ii) Find the equivalent parallel resistance and capacitance that causes a wein bridge to null if the following components are given:
R1= 8kΩ, C1 = 6µF
R2 = 30k Ω, f=2.5 kHz
R3 = 1kΩ (10+6)
Or
(b) Discuss briefly on types of instrument errors and instrument faults. With neat figure explain the need of WAGNER’S EARTH (ground) connection in bridge circuit (10+6)
14. (a) With neat figures explain the construction and working principle of a digital storage Oscilloscope. Compare its its advantages over an analog CRO.(10+6)
Or
(b) Write briefly on any TWO: (8+8)
(i)Dot matrix display
(ii) Advantage and principle of LCD Displays
(iii) Digital data logger.
15. (a) How are A/D converters classified? With neat diagram explain the construction and principle of successive approximation  type ADC?. (2+14)
Or
(b) (i) Write briefly on thermocouple and thermistors as temperature transducers. (8)
(ii) With neat figure explain LVDT for velocity measurement. (8)

NOVEMBER DECEMBER 2009

1.     Differentiate resolution from threshold

2.     How are the absolute and relative errors expressed mathematically

3.     What are the essential torques required for operating an instrument?

4.     What is phase meter? Mention the types of phase meter

5.     What is an isolation amplifier? Where is it used?

6.     State the condition for balance in a wheatstone bridge

7.     What are the types of printers according to printing methodology?

8.     What are the main parts of the cathode ray tube?

9.     Differentiate sensor from transducer.

1   Draw the block diagram for 4 bit analog to digital converter.

(    Define and explain the static characteristics of an instrument.

(b) (i) draw and explain the general block diagram of measurement system.

     (ii) write an note on different types of errors.

 12.(a) describe the construction and working principle of single phase induction type energy meter. Write a short note on any two adjustments required in energy meters.

(b) explain with neat sketch the classification of Instrument transformers write a note on the errors affecting the characteristics of an instrument transformer.

13.(a) with a neat sketch describe a bridge to determine the unknown inductance and a bridge to determine the unknown capacitance.

(b)explain the grounding techniques in detail to reduce the ground loop interference signal.

14.(a) describe the LED and LCD display devices.

(b) describe the direct and frequency modulation magnetic tape recording types. Give its merits and demerits.

15 (a) what are the selection criteria for the transducer? Explain the working principle of LVDT with neat sketch and characteristics. Give advantages, disadvantages and applications of LVDT

(b) what are the performance parameters of analog to digital converter? Explain any two basic A/D conversion techniques in detail.

UNIT 1   

PART-A

1. List out the dynamic characteristics of any measurement system.

2. What are the types of error measurement system?

3. What are the static characteristics important?

4. What is standard? What are the different types of standard?

5. What is the function of manipulation element in a measurement system?

6. What are the primary standards? Where are they used?

7. What is primary sensing element?

8. What is calibration?

9. Define the terms precision and sensitivity?

10. Define static error.

11. Distinguish re-productibility and repeatability.

12. Show the block diagram indicating functional elements of measurement system.

13. Distinguish between zero drift and span drift.

14. Define a dynamic response of an instrument.

15. What are the different calibration methodologies?

16. Define limiting errors and instrumental errors.

17. Mention any four static characteristics of measuring instruments.

18. Distinguish between direct and indirect methods of measurements.

19. What is the significance of calibration?

20. What is meant by accuracy and precision of an instrument?

21. List the different types of possible errors in measurements.

22. What is the difference between analog and digital instrument?

23. What are absolute instruments?

24. What is a secondary instrument?

25. How are secondary instruments classified?

PART-B

2.) 16 Marks

1. Draw the block diagram showing the basic functional elements of an instrument and explain the functions of each.

2. Define limiting errors. Derive the expression for relative limiting errors.

3. Explain in detail calibration techniques and draw the calibration curve in general.

4. Give the methods of using any three standard inputs being used for analyzing the dynamic response of system with neat sketches.

5. Explain on the static and dynamic characteristics of a measurement system.

6. Describe in detail the different types of dynamic errors in a measurement system.

7. By using a micro meter screw the following readings were taken of a certain physical length.

UNIT2

PART-A

1. What is creeping and how it is prevented?

2. What is the working principle of wattmeter employed in measuring instruments?

3. How are the analog instruments classified on the basis of method used for comparing the unknown quantity?

4. Give the advantages of moving iron meters.

5. What are different methods of measurement of frequency in the power frequency range?

6. Explain why it is necessary to make the potential coil circuit purely resistive in wattmeters.

7. What are the advantages of digital instruments over analog instruments?

8. How are resistors are checked using digital multimeters?

9. What is auto ranging?

10. Define resolution of DVM.

11. What are volt-ampere hour and watt-hour?

12. What is the purpose of instrument transformers?

13. What are the various principles of analog type electrical instruments?

14. Give the importance of iron loss measurements.

15. What is the reason for using MI on both A.C and D.C?

16. What is the precaution to be followed while using current transformer?

17. What is transfer instrument?

18. Why the PMMC instrument is not used for a.c measurements?

19. What is the principle of ramp type digital voltmeter?

20. Which torque is absent in energy meter? Why?

21. Explain the purpose of Schmitt trigger in digital frequency meter.

22. What are the essential parts of a ramp type digital voltmeter?

23. Define nominal rate of instrument transformer.

24. Explain the following term as applied to digital displays 3 ½ digit and 4-½ digit display.

25. Explain the principle of digital phase meter.

PART-B

1. Derive the torque equation of electrodynamometer type instrument.

2. Explain with neat circuit diagram the working of successive approximation type DVM.

3. Draw the circuit diagram of digital phase meter and explain its working.

4. Give the construction and principle of operation of single phase induction type energy meter.

5. Describe the construction and functioning of mechanical type frequency meter.

6. Explain the functioning of Ferro-dynamic type electrical resonance frequency meter.

7. Describe the construction and working of PMMC instrument. Derive the equation for deflection if the instruments are spring controlled.

8. Derive the torque equation for an electro dynamometer type of wattmeter.

9. Write briefly with neat figures on (i) Principle of operation of a current transformer (ii) B-H curve analysis of a magnetic circuit.

10. Explain the working of moving iron instruments.

11. Explain the function of 3 phase energy meter and wattmeter.

12. How the range of d.c. Ammeter and d.c voltmeter can be extended? Derive the expressions to calculate shunt resistance and multiplier resistance.

13. Draw and explain the circuit diagram of digital frequency meter.

14. Explain the working of a digital multimeter with a schematic block diagram.

15. Explain the construction, working principle of a three-phase wattmeter. What is the importance of deflecting torque in these analog instruments?

UNIT3

PART-A

1. State the advantages of using the bridge circuits for the measurement.

2. What is the sensitivity of Wheat stone bridge?

3. What are the sources of errors in Wheat stone bridge?

4. Give the application and limitations of Wheat stone bridge.

5. Which measurement can be carried out by Maxwell bridge?

6. List the advantages of using standard capacitor in Maxwell bridge.

7. Give the advantage and limitations of Maxwell bridge.

8. What is Hay’s bridge?

9. Compare Hay’s bridge with Maxwell bridge.

10. What is Wien’s bridge?

11. Give the classification of external interference signals.

12. What is capacitance interference?

13. What is electrostatic shielding?

14. What is inductive interference?

15. State the method of reducing inductive interference.

16. What is electromagnetic interference?

17. State the sources of EM waves, which can cause interference.

18. State the method of reducing ground loop interference.

19. What is the standardization of potentiometer?

20. Write the application of d.c. Potentiometers.

21. Write the application of a.c. potentiometers.

PART-B

1. Derive the bridge balance condition for the Maxwell bridge and Schering bridge

2. Explain in detail about the laboratory type DC potentio meter.

3. Describe about the multiple earth and earth loops.

4. Explain the different techniques of grounding.

5. Describe the circuit of Kelvin double bridge used for measurement of low resistance.

6. Explain how the inductance is measured in terms of known capacitance using Maxwell’s bridge.

7. Explain the working of Schering bridge.

8. Which bridge is used to measure frequency and explain the measurement procedure?

9. With neat diagram explain in detail about Hay bridge.

10. Explain about the Anderson bridge.

UNIT4

PART-A

1. What are the advantages and disadvantages of FM method of magnetic tape recording?

2. What are the different types of amplifiers used for CRO’s?

3. Give the principle of LCD type display device.

4. Draw a neat diagram on X-Y recorder.

5. Write two advantages of LED on electronic displays.

6. What are the advantages of magnetic tape recorder?

7. What is isolation probe?

8. State the features of ink-jet printers.

9. What are the various methods of recording data?

10. In what way line printers are advantages over dot matrix printer?

11. What are the different types of magnetic recording?

12. What are the different materials used on LED?

13. What are data loggers?

14. What are the functions of data loggers?

15. What are the basic components of data loggers?

16. List the advantages of LCD.

17. What is the sweeper in oscilloscope?

18. List the controllers normally found on XY recorder.

19. What is a recorder? How are the classified?

20. Define the deflection sensitivity of CRT.

21. List the main parts of cathode ray tube.

22. Discuss the advantages and disadvantages of PDM recording.

23. What is the basic operating principle of digital tape recording?

24. What are the basic components of a tape recorder?

25. What are the advantages of LCD over LED?

PART-B

1. Explain the FM method of magnetic tape recording and explain its advantages and disadvantages.

2. Describe the principle of working and circuit diagram of a digital oscilloscope.

3. With neat figure explain the working principle of a digital CRO. What are its advantages of analog CRO.

4. Explain in detail how the data stored in magnetic disk and tape.

5. Describe the construction and working of LCD’s , mention the difference between light scattering and field effect types of LCD’s also explain the advantages of LCDs.

6. Discuss in detail about various types of recorders.

7. Discuss in detail about dot matrix displays.

8. Explain the various methods of magnetic recording.

9. Describe the pulse duration modulation (PDM) as used in magnetic tape recording and explain its merits and demerits.

10. With neat figure explain the construction and working principle of a digital storage oscilloscope. Compare its advantages over an analog CRO.

UNIT5

PATR-A

1. Define transducer.

2. Mention some advantages of electrical transducers.

3. Mention some basic requirements of a transducer.

4. What are the classifications of transducers?

5. What is primary transducer?

6. What is secondary transducer?

7. What is active transducer? Mention some example.

8. What is passive transducer? Mention some example.

9. What is analog and digital transducers?

10. What is inverse transducer?

11. What are the types of potentiometers?

12. What are the advantages and disadvantages of potentiometers?

13. Define strain gauges.

14. Define gauge factor.

15. Mention types of strain gauge.

16. What is resistance thermometer?

17. What are the advantages and disadvantages of resistance thermometers?

18. What is thermistor? State the advantage and disadvantages.

19. What is inductive transducer?

20. Mention some advantages and disadvantages of LVDT.

21. Mention the applications of LVDT.

22. What is the basic principle of capacitive transducer?

23. Mention some advantages and disadvantages of capacitive transducer.

24. What is piezo electric effect?

25. What are the materials used for piezo electric transducer?

26. What are the types of DAS? State the applications also.

27. What are the essential functions of digital DAC?

28. What are the types of ADC?

29. What are the types of DAC?

30. What is smart sensor? Mention some applications.

PART-B

1. How the transducers are classified on the basis of principle of operation?

2. Explain the generalized diagram of a digital data acquisition system?

3. Describe the different modes of operation of piezo electric transducers.

4. Describe in details the successive approximation method of ADC.

5. Describe the different principles of working of capacitive transducers.

6. Explain the construction and principle of working of a LVDT.

7. Explain about the thermistor and thermocouples.

8. Discuss R-2R ladder type DAC.

9. Explain the resistive transducer with respective potentiometer.

10. Explain the principle of operation of piezo electric transducer.

11. Discuss in detail about optical encoder, Resistive encoder and shaft encoder.

12. Explain in detail about ADC and DAC converters.