Ch. 2 (Electromagnetic Compatibility)

Question 1

Conducted coupling

Answer 1

Except solid state

Question 2

Internal EMI sources

Answer 2

Power lines
Motors
Cell phones
Except “incandescent lighting” or “electrical power cables”

Question 3

EMI sources (natural)

Answer 3

Atmospheric electricity

Cosmic radiation

Question 4

Electrostatic discharge

Answer 4

Spark in the air

Question 5

CRT

Answer 5

Cathode Ray Tube

Question 6

What interferes with CRTs

Answer 6

RFI

Question 7

Unwanted signals

Answer 7

CM - common mode

DM - differential mode

Question 8

An example of common mode

Answer 8

Locking up a computer

Question 9

Differential mode affects

Answer 9

Corrupting transmitted signals

Question 10

Types of EMI

Answer 10

Except unbalanced DM fields

Question 11

Coupling mutual capacitance/inductance

Answer 11

Except signal injector

Question 12

Tunnel problems

Answer 12

Except unbalanced DM fields

Question 13

Man-made EMI sources

Answer 13

Electrical power
Generator
Communications electronics

Question 14

ESD =

Answer 14

Electrostatic Discharge

Question 15

Types of ESD

Answer 15

Spark
Radiated
Contact

Question 16

ESD immunity

Answer 16

Contact level 2 - 4 KV
Contact level 4 - 8 KV
Air level 2 - 4 KV

Question 17

Less than 5KVA

Answer 17

No separation necessary

Question 18

Separation requirements for fluorescent lamps

Answer 18

5.12”

Question 19

Separation from power in grounded metal conduit

Answer 19

6”

Question 20

Separation from unshielded power lines near grounded metal conduit

Answer 20

12”

Question 21

Separation from unshielded power lines near open pathways

Answer 21

24”

Question 22

Separation from electrical motors & transformers

Answer 22

47”

Question 23

Mitigate unwanted signals w/ ___

Answer 23

Ferrite beads

Question 24

Magnetic scheme

Answer 24

Filters unwanted signals

Question 25

Two types of EMI

Answer 25

Man-made

Natural

Question 26

How to measure EMC

Answer 26

There is no technique

Question 27

EMC =

Answer 27

Electromagnetic Compatibility

Question 28

Separation for arc welders

Answer 28

31.5”

Question 29

Electromagnetic fields are ___ undesirable

Answer 29

Not always

Question 30

___ are created when inductive and capacitive circuits are switched on and off

Answer 30

Electrical fast transient (EFT) disturbances

Question 31

Inadequate gaskets/enclosures can be a source of ___

Answer 31

Radiated interference

Question 32

RMS power

Answer 32

.707

Question 33

Difference between two grounds should be no more than ___

Answer 33

1.00

Question 34

Modern electronics are ___ susceptible to EMI

Answer 34

More

Question 35

Instrumentation shield grounding

Grounding for longer shield runs

Answer 35

One end

Both ends

Question 36

Minimum CM rejection ratio

Answer 36

40 dB

Question 37

Visible light

Answer 37

10 to the 15th power