VALLIAMMAI ENGINEERING COLLEGE SRM Nagar, Kattankulathur – 603 203
Question Bank
DEPARTMENT OF ELECTRONICS AND COMMUNIUCATION EC6011 ELECTROMAGNETIC INTERFERENCE AND COMPATIBILITY Regulation: 2013 Academic Year: 2016 – 2017 (Odd Semester)
Prepared By:
Dr.S.Ramesh, Asso.Prof Mrs.K.Kamala, AP-S.G Mrs.T.S.Sheriba, A.P-S.G
VEC/ECE/EC6011‐EMIC/2015‐2017 ODD
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) Q.No
Questions
BT Level
Domain
1.
Analyse 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 is EMI 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.
Criticise 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.
List some of the EMC applications.
BTL‐4
Analyzing
17.
Classify EMI/EMC.
BTL‐4
Analyzing
18.
Summarise 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
20.
How can the hazards due to radiation be reduced or prevented?
BTL‐6
Creating
VEC/ECE/EC6011‐EMIC/2015‐2017 ODD
Part B (16 Marks)
1. (i) Write short notes on EMI Testing categories (10) BTL‐1 (ii) What are the various parameters of measurement? Give their relevant units. (6) 2.
(i) List out all the sources and victims of EMI? (ii) Write notes on each sources and victims with examples.
3.
(6) (10)
Remembering
BTL‐1
Remembering
(i) What is an intersystem EMI? How does it affect an 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 intrasystem EMI? How does it affect an 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) (8) (ii) Explain the interference elements present in an EMI system
BTL‐2
Understanding
6.
(8) (i) Give an account on radiation hazards. (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. (ii) Explain the tests performed for the conducted susceptibility.
(8) (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. (ii) Interpret the lightning discharge as a source of EMI.
BTL‐3
Applying
BTL ‐ 4
Analyzing
(8) BTL ‐ 4 (8)
Analyzing
(8) (8)
10.
(i) Analyze how an electrostatic discharges occur. (8) (ii) Investigate on details of how an EMI is caused by radiation Hazards.(8)
11.
(i) Explain the measurement performed for the conducted emission? (ii) Examine the role of Decoupling capacitors in digital IC’s.
12.
(i) Analyze the various issues of EMC in brief (ii) How does the conduction emission occur in Switched mode power supply. Discuss about the common mode noise in SMPS. (10)
(6) BTL ‐ 4
Analyzing
13.
Consider the past historical facts. Criticize on the impact of radio communication. Also discuss the role of electromagnetic susceptibility and compatibility in it. (16)
BTL‐5
Evaluating
14.
Generate suitable examples to explain the intentional and unintentional electromagnetic emissions during operation of various equipments. How to control them? (16)
BTL‐6
Creating
UNIT II COUPLING MECHANISMS
VEC/ECE/EC6011‐EMIC/2015‐2017 ODD
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. Sl.No.
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
PART A (2 Marks)
4. What is transient coupling?
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 BTL‐3 on.
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
Sl.No.
PART B (16 Marks)
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 BTL‐1 occur in the coupling path? (8) (ii) What is common mode coupling? Show how it affects a system in an electromagnetic environment. (8)
Remembering
VEC/ECE/EC6011‐EMIC/2015‐2017 ODD
3
Define radiated differential mode coupling? How In what way this is different BTL-1 from the radiated common mode coupling? (8) What are transient sources? How does the lightning discharge affect the electronic equipments? (8)
Remembering
4
What is ground loop coupling? State the causes of ground loop coupling. (6) Show how it 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) Illustrate 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. (ii) Summarize on Automotive transients.
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 main power supply affect the appliances. Explain. (8)
BTL‐3
Applying
10.
(i) Explain the concept behind Cross talk with help of PCB in detail. (8) (ii) Analyze how a coupling takes place in a supply network and how does it affect the network. (8)
BTL‐4
Analyzing
11.
(i) Explain how common mains supply acts as a frequent source of conducted interference. (8) (ii) Illustrate the electromagnetic impact of cable coupling in a system design .(8)
BTL‐4
Analyzing
12.
Analyze the effects of inductance in a two wire cable system. (8) Describe the effects of the capacitance that exists between the cables. (8)
BTL‐4
Analyzing
13.
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) Evaluate the effects of radiative coupling in an EM environment. (8)
BTL‐5
Evaluating
(8) (8)
VEC/ECE/EC6011‐EMIC/2015‐2017 ODD
14. How an electromagnetic field that appears in the atmosphere does gets coupled into the transmission or power cables? Calculate the induced voltage and current due to this coupling action. (8)
BTL‐6
Creating
Develop the scenarios which demonstrates the electromagnetic coupling between an emitter and a receptor. Support it with neat diagrams. (8)
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 Q.No
Questions
BT Level
Domain
1.
Analyse 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
9.
Point out the different Gasketting for EMI sealing.
BTL 5 Evaluating
10.
List out the coupling situations to be addressed during the physical layout process. 11. Classify the procedures for effective grounding in PCB design
BTL 1 Remembering 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
VEC/ECE/EC6011‐EMIC/2015‐2017 ODD
14.
Illustrate the terms grounding and bonding.
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.
2.
3. 4.
Discuss the shielding mechanism and derive the expression for the BTL 2 Understanding attenuation due to single shield and multimedia laminated shield with neat diagrams and equations. (16) (i) Show that the electromagnetic leakage occurs through shielding joints. BTL 3 Applying (6) (ii) Suggest the methods to reduce this electromagnetic leakage. (10) (i)How can a gasket be used to suppress the EM leakage at joints?(8) BTL 1 Remembering (ii)Write notes on sealing for EMI leakage. (8) Explain in detail about the different types of system grounding for EMI/EMC. BTL 2 Understanding (16)
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) 6. (i) Summarize on the methods to measure the ground resistance. (8) (ii) Brief out the preventions to be followed while earthing. (8)
BTL 4 Analyzing
7.
BTL 1 Analyzing
8. 9.
10.
11.
Analyze the factors considered for a telephone line filter design. How does this factor influence the filter design? Explain with necessary examples. (16) Summarize about various lumped element low pass filter schemes for EMI mitigation. Also compare their performances. Write notes on (i) Surge protection and suppression (ii) Transient protection and suppression (ii) Low Frequency (LF) magnetic field shielding (5)+(5)+(6) “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 150 kHz and 30 MHz for a differential mode and common mode. (16) 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 1 Remembering
BTL 2
Understanding
BTL 1 Remembering
BTL 5 Evaluating
BTL 6 Creating
VEC/ECE/EC6011‐EMIC/2015‐2017 ODD
12.
(i) Investigate on how the component selection and mounting controls BTL 4 Analyzing EMI.(6) (ii) Explain about PCB to chassis ground connection and effects of apertures. (10) 13. (i) What are all the procedures used for effective grounding in PCB design? BTL 1 Remembering (8) (ii) Brief about electromagnetic compatibility that is achieved while PCB is prepared for industry applications. (8) BTL 3 Applying 14. (i) Illustrate the consequence of different shielding materials over the shielding. Tabulate some of the shielding materials and their uses.(8) (ii) Demonstrate the shielding integrity at discontinuities. (8) 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 Q.No
Questions
BT Level
Domain
1.
List out the EMI/EMC civilian standards.
BTL 1 Remembering
2.
What for MIL STD 461, 462 and 463 are used?
BTL 1 Remembering
3.
Which are the class A devices with reference to FCC?
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
8.
State the objective of requirements CS 103/104/105.
BTL 1 Remembering
9.
Idenfify 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 MIL 461E / 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 need for EMI standards?
BTL 2 Understanding
VEC/ECE/EC6011‐EMIC/2015‐2017 ODD
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.
Pointout the two types of EMC Product standard.
BTL 4 Analyzing
PART – B
1. What does the standard MIL 461E 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) 2. (i) Express the needs to meet for EMI standards? Explain. (8) (ii) Discuss briefly of FCC regulations. (8) 3. Develop the conducted interference controls, radiated interference controls and susceptibility at intermediate levels of exposure in MIL STD 461/462 standard. (16) 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) 5. Analyze the purpose of EMI standards and give different types of standards that followed in different countries? (16)
BTL 1 Remembering
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) 7. Write about Comite Special des Perturbations Radioelectrique (CISPR) and International Electrotechnical Commission (IEC) standards. (8+8) 8. (i) Explain in detail the usage of ANSI standards in EMC area. (8) (ii) Pointout why military standards are more stringent for RE and RS. (8) 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) 10. Summarize FCC and CISPR Conducted Emission (CE) and Radiated Emission (RE) standards. (16) 11. Write short notes on (i) British Standard Institution (BSI) (ii) Comite European de Normalisation Electrotechniques (CENELEC).(8+8) 12. (i) Determine the generic standards for residential and industrial environments.(8) (ii) Validate the VDE standards and pulsed interference immunity. (8) 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 2 Understanding
BTL 2 Understanding BTL 6 Creating
BTL 4
Analyzing
BTL 4
Analyzing
BTL 1 Remembering
BTL 4
Analyzing
BTL 1 Remembering
BTL 2 Understanding BTL 1 Remembering BTL 5 Evaluating BTL 3 Applying
VEC/ECE/EC6011‐EMIC/2015‐2017 ODD
14.
Illustrate on how the spectrum conservation can be achieved through proper BTL 3 Applying frequency assignment. (16) 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 STD test methods. PART A Q.No
Questions
BT Level
Domain
1.
Draw two arrangements of OATS
BTL 1 Remembering
2.
What are the advantages of OATS?
BTL 1 Remembering
3.
List the features of current probe and power probe
BTL 1 Remembering
4.
Illustrate the significance of narrow band testing.
BTL 2 Understanding
5.
Assess the Near Field sources in Shielding effectiveness
BTL 5 Evaluating
6.
List the various measurement precautions in OATS
BTL 1 Remembering
7.
Illustrate at least two standards for design guidelines and test & measurement procedures published by IEEE/ANSI.
BTL 3 Applying
8.
What is a TEM Cell
BTL 1 Remembering
9.
BTL 3 Applying
10.
Identify atleast two standards for test &measurement procedures published by IEEE/ANSI. Compare radiated measurements for class A devices and others.
BTL 4 Analyzing
11.
Formulate the spectrum bandwidth that will be occupied by a radio station
BTL 6 Creating
12.
Give the list of antenna used for microwave frequencies.
BTL 2 Understanding
13.
State the recommended ambient conditions for air discharge mode testing.
BTL 1 Remembering
14.
Generalize the requirements of Military STD for EMC testing?
BTL 2 Understanding
15.
Discuss on how test bed is selected for ESD testing.
BTL 2 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 an equation for spectral efficiency that depends on the useful information from the radio equipment.
BTL 6 Creating
VEC/ECE/EC6011‐EMIC/2015‐2017 ODD
19.
Summarize the commonly used test antennas with frequency
BTL 5 Evaluating
20.
Differentiate Military standard and Civilian standards in measurements.
BTL 4 Analyzing
PART – B
1.
(i)Write short notes on sensors/Injectors. (ii)Write short notes on couplers.
2.
(i) Express the needs to meet for EMI standards for testing methods. (8) (ii) Discuss briefly about ESD test bed. (8) (i) Formulate the various EMI Test instruments. (8) (ii) Develop a test bed for EFT. (8) (i) Compare Euro norms standards in Japan. (8) (ii) Infer details about EMI specifications and its limits with respect to civilian and military standards for measurements (8) Analyze the schematic that enables the measurements using Anechoic chamber. (8) Explain how testing is performed in an open environment. (8) Describe about the open area test site measurements. What are its limitations?(8) Outline the characteristics of open area test site. (8)
BTL 2 Understanding
Write short notes on Broadband measurement antennas a) The Biconical Antenna (8) b) Log-Periodic Antenna (8) Explain briefly about the measurements using an anechoic chamber. (8) Explain about Line Impedance Stabilization Networks. (8) (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) (i)What do you mean by shielding? Explain the Near Field sources in Shielding effectiveness. (10) (6) (ii) Write a note on Shielded anechoic chamber . Write short notes on (i) Measurement of CM and DM Interferences (ii) Conducted EMI in ships and Aircraft (8+8) (i)Determine various testing antenna and their frequencies as specified in CISPR standard. (8) Enumerate the measurements using EMI Rx and spectrum analyser. (8) (i) Demonstrate the regulatory model for radiated emissions from electrical equipment. (8) (ii) How do you perform testing using Giga Hertz TEM Cell. (8) (i) Illustrate on how the spectrum conservation can be achieved through proper frequency assignment. (10) (ii)Build EMI coupling network. (6)
BTL 1 Remembering
3. 4.
5.
6. 7.
8. 9.
10.
11. 12.
13.
14.
(8) (8)
BTL 1 Remembering
BTL 6 Creating BTL 4
Analyzing
BTL 4
Analyzing
BTL 2 Understanding
BTL 4
Analyzing
BTL 1 Remembering
BTL 2 Understanding
BTL 1 Remembering BTL 5 Evaluating
BTL 3 Applying
BTL 3 Applying
VEC/ECE/EC6011‐EMIC/2015‐2017 ODD
