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VALLIAMMAI ENGINEERING COLLEGE

SRM Nagar, Kattankulathur – 603 203

Question Bank

DEPARTMENT OF ELECTRONICS AND COMMUNIUCATION

EC6011 ELECTROMAGNETIC INTERFERENCE AND COMPATIBILITY

Regulation: 2013

Academic Year: 2017 – 2018 (Odd Semester)

Prepared By

Dr. S. Ramesh, Associate Professor,

Dr. N. Rajesh, AP- O.G,

Mrs. K. Kamala, AP - S.G.

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UNIT I ‐BASIC THEORY

Introduction to EMI and EMC, Intra and inter system EMI, Elements of Interference, Sources and Victims

of EMI, Conducted and Radiated EMI emission and susceptibility, Case Histories, Radiation hazards to

humans, Various issues of EMC, EMC Testing categories, EMC Engineering Application.

Part‐ A (2 Marks)

S. No Questions BT

Level

Domain

1. Analyze the need for electromagnetic compatibility. BTL 4 Analyzing

2. Write some of the testing strategies in EMC. BTL 1 Remembering

3. Identify the three criteria to be satisfied by any system to become

electromagnetically compatible.

BTL 1 Remembering

4. Discuss the steps to prevent emission that causes the EMI in a system. BTL 2 Understanding

5. Why EMI is a vital problem? BTL 1 Remembering

6. We feel electric shock at times, when we touch TV and Computer monitors.

Give the reason.

BTL 2 Understanding

7. List the sources of EMI. BTL 1 Remembering

8. Give the explanation about the conducted coupling of EMI. BTL 2 Understanding

9. Explain why a bike started or a mixie under running condition disturbs a TV

receivers functioning.

BTL 2 Understanding

10. Where is a decoupling capacitor used? Why? BTL 1 Remembering

11. Illustrate various types of radiation coupling in EMI. BTL 3 Applying

12. Choose which coupling happens directly between the emitter and receptor. BTL 3 Applying

13. What is the possibility to develop circuit models of EMI with correct reason? BTL 3 Applying

14. Criticize on the two factors that tend to affect the amount of interference that

would otherwise be transmitted along a conducted path.

BTL 5 Evaluating

15. Define EMI and EMC. BTL 1 Remembering

16. Differentiate conducted and radiated emission. BTL 4 Analyzing

17. Classify EMI/EMC and List some of the EMC applications. BTL 4 Analyzing

18. Summarize the effect of EMI on secured communications. BTL 5 Evaluating

19. What would happen if the coupling path is not properly shielded? Justify

BTL 6 Creating

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20. How can the hazards due to radiation be reduced or prevented? BTL 6 Creating

Part‐B (16 Marks)

1. (i) Write short notes on EMI Testing categories (10)

(ii) What are the various parameters of measurement? Give their relevant

units. (6)

BTL 1 Remembering

2. (i) List out all the sources and victims of EMI with examples? (8)

(ii) Write the various mechanisms in which electromagnetic interference can

travel from its source to the receptor. (8)

BTL 1 Remembering

3. (i) What is an intersystem EMI? How does it affect equipment in an EM

environment? (8)

(ii) Select and write about the case histories related to intersystem EMI. (8)

BTL 1 Remembering

4. (i) What is an intra system EMI? How does it affect equipment in an EM

environment? (8)

(ii) Write about the case histories related to intersystem EMI. (8)

BTL 1 Remembering

5. (i) Distinguish between the features of conducted EMI and radiated EMI. (8)

(ii) Explain the interference elements present in an EMI system (8)

BTL 2 Understanding

6. (i) Give an account on radiation hazards. (8)

(ii) Explain in detail the conducted EMI and radiated EMI with examples. (8)

BTL 2 Understanding

7. (i) Identify how a conducted emission occurs in an EM environment. (8)

(ii) Explain the tests performed for the conducted susceptibility. (8)

BTL 2 Understanding

8. (i) Illustrate proper industrial citations to explain the significance of EMI in a

system design. (8)

(ii) Show how celestial bodies act as a source of EMI. (8)

BTL 3 Applying

9. (i) Select a proper testing methodology for radiation emissions and

susceptibility. Explain. (8)

(ii) Interpret the lightning discharge as a source of EMI and discuss on the

strong sources of atmospheric noise. (8)

BTL 3 Applying

10. (i) Analyze how an electrostatic discharge occur. (8)

(ii) Investigate on details of how an EMI is caused by radiation Hazards. (8)

BTL 4 Analyzing

11. (i) Explain the measurement performed for the conducted emission? (8)

(ii) Examine the role of decoupling capacitors in digital IC‟s. (8)

BTL 4 Analyzing

12. (i) Analyze the various issues of EMC in brief. (6)

(ii) How does the conduction emission occur in Switched mode power

supply? Discuss about the common mode noise in SMPS. (10)

BTL 4

Analyzing

13. Consider the past historical facts. Criticize on the impact of radio

communication. Also discuss how lightning discharges affect the

transmission line communication. (16)

BTL 5 Evaluating

14. Generalize the discrimination between time domain and frequency domain

EMI. Why analysis is made in frequency approach analysis, design and

BTL 6 Creating

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location of high voltage equipments? (16)

UNIT II COUPLING MECHANISMS

Electromagnetic field sources and Coupling paths, Coupling via the supply network, Common mode

coupling, Differential mode coupling, Impedance coupling, Inductive and Capacitive coupling, Radiative

coupling, Ground loop coupling, Cable related emissions and coupling, Transient sources, Automotive

transients.

PART‐A (2 Marks)

S.No. Questions BT

Level

Domain

1. List out the types of coupling between cables. BTL 1 Remembering

2. Define ground coupled interference. BTL 1 Remembering

3. Draw the elements of interference in a basic system with source and receptor. BTL 1 Remembering

4. What is transient coupling and factors that influence grounding scheme? BTL 1 Remembering

5. Draw common mode and differential mode coupling in circuits. BTL 1 Remembering

6. Describe the effect of cross talk with reference to EMI/EMC design issues. BTL 2 Understanding

7. Give suitable explanation for „Ground‟ with respect to working on electrical

gadgets.

BTL 2 Understanding

8. Express the impacts of electromagnetic emission. BTL 2 Understanding

9. Discuss the way by which one can avoid power mains interference. BTL 2 Understanding

10. Illustrate the steps in the procedure to analyze EMP susceptibility. BTL 3 Applying

11. What would happen if conductive transfer occurs? BTL 6 Creating

12. Classify the factors that the noise voltage developed in a closed loop, depend

on.

BTL 3 Applying

13. Criticize the need of ground loop coupling. BTL 5 Evaluating

14. Explain Automotive transient. BTL 4 Analyzing

15. Analyze the drawbacks of various coupling mechanisms. BTL 4 Analyzing

16. Explain power supply and power main coupling. BTL 4 Analyzing

17. Combine the effect of radiation and conduction coupling and discuss its

effect.

BTL 6 Creating

18. Define LISN. BTL 1 Remembering

19. Point out the important techniques to control EMI at source point. BTL 3 Applying

20. Explain how the field coupling affects the system? BTL 5 Evaluating

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PART‐B (16 Marks)

S.No. Questions BT

Level

Domain

1

(i) What are the electromagnetic field sources found in an electromagnetic

environment? Discuss. (8)

(ii) Define coupling. What are the types of coupling encountered in an EM

environment? Discuss. (8)

BTL 1 Remembering

2 (i) Define coupling path. What are the electromagnetic interferences that

occur in the coupling path? (8)

(ii) What is common mode coupling? Show how it affects a system in an

electromagnetic environment. (8)

BTL 1 Remembering

3 (i) Define radiated differential mode coupling? How In what way this is

different from the radiated common mode coupling? (8)

(ii) What are transient sources? How does the lightning discharge affect the

electronic equipments? (8)

BTL 1 Remembering

4 (i) What is ground loop coupling? State the causes of ground loop coupling.

(6)

(ii) Show how ground loop coupling affects the grounding in a system that is

a part of the electromagnetic environment. (10)

BTL 1 Remembering

5 (i) Illustrate in detail the conducted and radiated coupling. (8)

(ii) Demonstrate the common impedance ground couplings with examples.

(8)

BTL 2 Understanding

6 (i) Demonstrate the effect of cross talk in a three conductor transmission line.

(8)

(ii) Discuss in detail about power supply coupling. (8)

BTL 2 Understanding

7 (i) Describe the cable related emissions and coupling briefly. (8)

(ii) Summarize on Automotive transients. (8)

BTL 2 Understanding

8 (i) Describe about the inductive coupling supporting with neat diagrams and

scenarios. (8)

(ii) Explain how the electrostatic discharge affects the digital circuits and

control panels. (8)

BTL 3 Applying

9 (i) Explain the capacitive coupling that occurs between the two cables

running parallel to each other. (8)

(ii) Identify how surges occurring on power supply affect the appliances.

Explain. (8)

BTL 3 Applying

10. (i) Explain the concept behind cross talk with help of PCB in detail. (6)

(ii) Analyze how a coupling / surges takes place on main power supply

network and how does it affect the appliances / network and how it can be

avoided with appropriate design. (10)

BTL 4 Analyzing

11. (i) Examine how common mains supply acts as a frequent source of

conducted interference. (8)

BTL 4 Analyzing

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(ii) Illustrate the electromagnetic impact of cable coupling in a system

design. (8)

12. (i) Analyze the effects of inductance in a two wire cable system. (8)

(ii) Describe the effects of the capacitance that exists between the cables.(8)

BTL 4

Analyzing

13. (i) Justify the reasons of how the cable coupling, near and far coupling of

EM fields produced can be reduced. Also, suggest the ways to enhance the

immunity of circuits/equipments/systems. (8)

(ii) Evaluate the effects of radiative coupling in an EM environment. (8)

BTL5 Evaluating

14. (i) How an electromagnetic field that appears in the atmosphere does get

coupled into the transmission or power cables? Calculate the induced

voltage and current due to this coupling action. (8)

(ii) Develop the scenario which demonstrates the electromagnetic coupling

between an emitter and a receptor. Support it with neat diagrams. (8)

BTL 6 Creating

UNIT III EMI MITIGATION TECHNIQUES

Working principle of Shielding and Murphy’s Law, LF Magnetic shielding, Apertures and shielding

effectiveness, Choice of Materials for H, E, and free space fields, Gasketting and sealing, PCB Level shielding,

Principle of Grounding, Isolated grounds, Grounding strategies for Large systems, Grounding for mixed

signal systems, Filter types and operation, Surge protection devices, Transient protection.

PART A

S. No Questions BT

Level

Domain

1. Analyze EMI shielding and its need. BTL 4 Analyzing

2. What is Murphy‟s Law? BTL 1 Remembering

3. List the Choice of Materials for shielding. BTL 1 Remembering

4. Define shielding effectiveness. BTL 1 Remembering

5. Formulate the shielding effectiveness of E and H‐fields. BTL 6 Creating

6. Summarize various shielding methods. BTL 2 Understanding

7. Interpret the all the tests that can be carried over in a shielding room. BTL 2 Understanding

8. Explain the need for EMI Gaskets. BTL 4 Analyzing

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9. Explain the different Gasketting for EMI sealing. BTL 5 Evaluating

10. List out the coupling situations to be addressed during the physical layout

process.

BTL 1 Remembering

11. Classify the procedures for effective grounding in PCB design BTL 4 Analyzing

12. Discuss about the advantages of multipoint grounding. BTL 2 Understanding

13. Chemical Salting has to be repeated for every 2 or 3 years for better

grounding effect–Justify.

BTL 5 Evaluating

14. Illustrate the terms grounding and bonding, opto - isolator? BTL 3 Applying

15. Classify EMI filters. BTL 3 Applying

16. What is meant by „bulging‟ capacitor? BTL 1 Remembering

17. Estimate the insertion loss of the filter. BTL 6 Creating

18. Estimate the functionality of transient suppressors. BTL 2 Understanding

19. Draw the diagram of gas tube surge suppressor and arrestors. BTL 1 Remembering

20. Show all the procedures that have to be considered for cable routing. BTL 3 Applying

PART – B

1. Discuss the various types of shielding techniques and derive the expression

for the attenuation due to single shield and multimedia laminated shield with

neat diagrams and equations. (16)

BTL 2

Understanding

2. (i) Show that the electromagnetic leakage occurs through shielding joints.

(6)

(ii) Suggest the methods to reduce this electromagnetic leakage. (10)

BTL 3 Applying

3. (i)How can a gasket be used to suppress the EM leakage at joints? (8)

(ii)Write notes on sealing for EMI leakage. (8)

BTL 1 Remembering

4. Explain in detail about the different types of system grounding for

EMI/EMC. (16)

BTL 2 Understanding

5. (i) Describe a filter help in suppressing undesired conducted electromagnetic

interference?

(ii) Support your answer with the help of lumped element low pass filter.

(8)+(8)

BTL 4 Analyzing

6. (i) Summarize on the methods to measure the grounding with examples.(8)

(ii) Brief out the preventions to be followed while earthing. (8)

BTL 1 Remembering

7. Analyze the factors considered for a telephone line filter design. How does

this factor influence the filter design? Explain with necessary examples. (16)

BTL 4 Analyzing

8. Summarize about various lumped element low pass filters for EMI

mitigation. Also compare their performances. (16)

BTL 2

Understanding

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9. Write notes on(i)Surge protection and suppression (ii)Transient protection

and suppression (ii) Low Frequency (LF) magnetic field shielding

(5)+(5)+(6)

BTL 1 Remembering

10. “The insertion loss of a particular filter depends on the source and load

impedances, and therefore cannot be stated independently of the termination

impedances.”Justify the above statement and prove it numerically. Also,

determine the insertion loss at 150kHz and 30MHz for a differential mode

and common mode. (16)

BTL 5 Evaluating

11. For a Residential power distribution system, analyze the requirements and

the steps to design a safety grounding system considering the two wires and

three wires grounding scenario. (16)

BTL 6 Creating

12. (i) Investigate on how the components election and mounting controls EMI.

(6)

(ii) Explain about PCB to chassis ground connection and effects of apertures.

(10)

BTL 4 Analyzing

13. (i) What are all the procedures grounding strategies i) Large systems ii)

Mixed signal systems? (8)

(ii) Brief about electromagnetic compatibility that is achieved while PCB is

prepared for industry applications. (8)

BTL 1

Remembering

14. (i) Illustrate the consequence of different shielding materials over the

shielding. Tabulate some of the shielding materials and their uses. (8)

(ii) Demonstrate how does an isolation transformer control EMI? Explain

Shielding and filtering methods of controlling EMI. (8)

BTL 3 Applying

UNIT IV STANDARDS AND REGULATION

Need for Standards, Generic/General Standards for Residential and Industrial environment, Basic Standards,

Product Standards, National and International EMI Standardizing Organizations; IEC, ANSI, FCC, AS/NZS,

CISPR, BSI, CENELEC, ACEC. Electro Magnetic Emission and susceptibility standards and specifications,

MIL461E Standards.

PART A

S. No Questions BT

Level

Domain

1. List out the EMI/EMC civilian standards. BTL 1 Remembering

2. What for MILSTD-461, 462 and 463 are used? BTL 1 Remembering

3. Which the FCC limits are for conducted and radiated emissions for class A

equipments?

BTL 1 Remembering

4. Give the reason why CISPR standards evolved. BTL 2 Understanding

5. Can High Voltage lines be allowed to cross residential sites? Justify. BTL 5 Evaluating

6. Quote the CISPR standards for EMIC. BTL 1 Remembering

7. Illustrate at least two standards for design guidelines and test&

Measurement procedures published by IEEE/ANSI.

BTL 3 Applying

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8. State the objective of requirements CS103/104/105. BTL 1 Remembering

9. Identify the expansion of the terms CISPR, FCC. BTL 3 Applying

10. Differentiate military and civilian standards. BTL 4 Analyzing

11. Propose the Standards for generic products to be used in industrial

environments?

BTL 6 Creating

12. Summarize few parameters of MIL461E / 462. BTL 2 Understanding

13. Define IEC and BSI. BTL 1 Remembering

14. Discuss the special requirements of MIL STD 461E for EMC testing? BTL 2 Understanding

15. Interpret the purpose of EMC standards? BTL 2 Understanding

16. Construct the main function of ACEC. BTL 3 Applying

17. Analyze the key for Conducted Emission (CE) EMC standards? BTL 4 Analyzing

18. Prepare the AS/NZS standards? BTL 6 Creating

19. Assess modular approval standards. BTL 5 Evaluating

20. Point out the two types of EMC Product standard. BTL 4 Analyzing

PART – B

1. What does the standard MIL461E emphasize? What are the problems one

may face by violating the regulations in it? If possible, a case study be

referred to support your justification. (16)

BTL 1 Remembering

2. (i) Express the needs to meet for EMI standards? Explain. (8)

(ii) Discuss in detail the specifications for emission and susceptibility given

in MIL461E standard. (8)

BTL 2 Understanding

3. Develop the conducted interference controls, radiated interference controls and

susceptibility at intermediate levels of exposure in MIL STD 461/462

standard. (16)

BTL 6 Creating

4. (i) Compare Euro norms standards in Japan. (8)

(ii) Infer details about EMI specifications and its limits with respect to

civilian and military standards. (8)

BTL 4 Analyzing

5. Analyze the purpose of EMI standards and give different types of standards

that followed in different countries? (16)

BTL 4 Analyzing

6. Distinguish between the FCC‟s EMC requirement and the European Union‟s

EMC requirements? What additional emission requirements does the

European Union have that the FCC does not? (16)

BTL 2 Understanding

7. Write about Civilian standards FCC, Comite Special des Perturbations Radio

electrique (CISPR) and International Electro technical Commission (IEC)

standards. (5+5+6)

BTL 1 Remembering

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8. (i) Explain in detail the usage of ANSI standards in EMC area. (8)

(ii) Point out why military standards are more stringent for RE and RS. (8)

BTL 4 Analyzing

9. (i) List out the IEC specifications adopted by ANSI standard. (8)

(ii) Briefly explain the MIL standards are useful in the area of EMI/EMC.

(8)

BTL 1 Remembering

10. Summarize FCC and CISPR Conducted Emission (CE) and Radiated

Emission (RE) standards. (16)

BTL 2 Understanding

11. Write short notes on (i) British Standard Institution (BSI)

(ii) Comite European de Normalisation Electrotechniques (CENELEC).(8+8)

BTL 1 Remembering

12. (i) Determine the generic standards for residential and industrial

environments. (8)

(ii) Validate the VDE standards and pulsed interference immunity. (8)

BTL 5 Evaluating

13. (i) Demonstrate the regulatory model for radiated emissions from electrical

equipment. (8)

(ii) Show that how US organizations involved with EMC for commercial

standards. (8)

BTL 3 Applying

14. Illustrate on how the spectrum conservation can be achieved through proper

frequency assignment. (16)

BTL 3 Applying

UNIT V EMI TEST METHODS AND INSTRUMENTATION

Fundamental considerations, EMI shielding Effectiveness tests, Open field test, TEM cell for immunity test,

Shielded Chamber, Shielded anechoic chamber, EMI test receivers, Spectrum Analyzer, EMI test wave

simulators, EMI coupling networks, Line impedance stabilization networks, Feed through capacitors,

Antennas, Current Probes, MIL-STD test methods, Civilian test methods

PART A

S.No Question BTL

level

Domain

1 Draw two arrangements of OATS BTL 1 Remembering

2 Why is shielded chamber needed for EMI testing? BTL 1 Remembering

3 Enlist the test methods available to measure the Shielding Effectiveness also

give the expression.

BTL 1 Remembering

4 Illustrate the significance of narrow band testing. BTL2 Understanding

5 Assess the Near Field sources in Shielding effectiveness. BTL5 Evaluating

6 List the various measurement precautions in OATS BTL 1 Remembering

7 Illustrate the block diagram of ESD simulator. BTL 3 Applying

8 What is the need for coupling/decoupling network and show the basic

arrangements.

BTL 1 Remembering

9 Identify at least two standards for test &measurement procedures published by

IEEE/ANSI.

BTL 3 Applying

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10 Compare radiated measurements for class A devices and others. BTL4 Analyzing

11 Formulate the spectrum bandwidth that will be occupied by a radio station BTL6 Creating

12 Give some commonly used test antenna and the useful frequency range for

each.

BTL2 Understanding

13 State various types of EM modeling methodologies used in signal integrity

analysis.

BTL 1 Remembering

14 Generalize the requirements of Military STD for EMC testing? BTL2 Understanding

15 Discuss on how test bed is selected for ESD testing. BTL2 Understanding

16 With LISN illustrate the basic circuit used for RI measurements BTL 3 Applying

17 Point out two very important needs for TEM cell. BTL 4 Analyzing

18 Develop the equation for the measurement of site attenuation and Antenna

Factor (AF).

BTL 6 Creating

19 Summarize the sources of inaccuracies in the TEM cell measurements. BTL 5 Evaluating

20 Differentiate Military standard and Civilian standards in measurements. BTL 4 Analyzing

PART B

1 Give a detailed account on EMI test receivers and EMI test wave simulators.

(16)

BTL 1 Remembering

2 (i) Explain the principles of operation of current probe. (8)

(ii) Discuss in detail about the functioning of feed through capacitor. (8)

BTL 2 Understanding

3 (i) Formulate the various EMI Test instruments. (8)

(ii) Develop a test bed for EFT. (8)

BTL 6 Creating

4 (i) Examine the method of measuring site attenuation and antenna factor. (8)

(ii) Infer about EMI specifications and its limits with respect to civilian and

military standards. (6)

BTL 4 Analyzing

5 Outline the construction of an anechoic chamber used for EMI measurement

and explain the procedure for RE and RS measurement. (16)

BTL 4 Analyzing

6 (i) Describe about the open area test site measurements. What are its

limitations? (8)

(ii) Outline the characteristics of open area test site. (8)

BTL 2 Understanding

7 Write short notes on Broadband measurement antennas

(i) The Bi-conical Antenna (8)

(ii) Log-Periodic Antenna (8)

BTL 1 Remembering

8 (i) Explain briefly about the measurements using an anechoic chamber. (8)

(ii) Explain about Line Impedance Stabilization Networks. (8)

BTL 4 Analyzing

9 (i) List out the various equipment used for Conducted EMI. (6)

(ii) Explain briefly the MIL-STD test methods useful in the area of

EMI/EMC. (10)

BTL 1 Remembering

10 (i) Outline various shielding effectiveness test used to determine the level of

attenuation of an EMI shield. (10)

(ii) Illustrate the construction of the Shielded anechoic chamber. (6)

BTL 2 Understanding

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11 Write short notes on

(i) Measurement of CM and DM Interferences.

(ii) Conducted EMI in ships and Aircraft. (8+8)

BTL 1 Remembering

12 (i) Explain about the source of inaccuracies using anechoic chamber

measurements. (8)

(ii) Enumerate the measurements using EMI Rx and spectrum analyzer. (8)

BTL 5 Evaluating

13 (i) Demonstrate the Radiation Susceptibility test using TEM cell. (8)

(ii) How do you perform testing using Giga Hertz TEM cell? (8)

BTL 3 Applying

14 (i) Illustrate on how the spectrum conservation can be achieved through

proper frequency assignment. (10)

(ii) Construct an EMI coupling network and give its need. (6)

BTL 3 Applying