BICSI - Chapter 2:Electromagnetic Compatibility: Detail View

1)

472. Which of the following is the ability of a device, equipment, or system to operate properly in its intended electromagnetic environment without introducing significant electromagnetic interference into the environment? a. Electromagnetic compatibility b. Electromagnetic interference c. Electromagnetic coupling

A. Electromagnetic compatibility(Chapter 2-Pg.1)

2)

473. Which of the following is the transfer of electromagnetic energy from one device or system to another in the same environment, causing interference with the normal operation of devices or systems? a. Electromagnetic compatibility b. Electromagnetic interference c. Electromagnetic coupling

B. Electromagnetic interference(Chapter 2-Pg.1)

3)

474. EMI increases when devices or systems share a common electromagnetic environment and their frequencies overlap. If they operate over a different range, higher levels of EMI can be expected. True or False

False(Chapter 2-Pg.1)

4)

475. All of the following are mechanisms that can cause coupling between two circuits or systems, except: a. Conductive coupling d. Inductive coupling b. Transference coupling e. Electromagnetic coupling c. Capacitive coupling

B. Transference coupling(Chapter 2-Pg.1)

5)

476. Which of the following couplings is defined as produced by magnetic fields? a. Conductive coupling d. Inductive coupling b. Transference coupling e. Electromagnetic coupling c. Capacitive coupling

D. Inductive coupling(Chapter 2-Pg.1)

6)

477. To lessen EMC problems, identify at least two of the three elements and eliminate or reduce the influence of the third one. True or False

True(Chapter 2-Pg.1)

7)

478. The electromagnetic spectrum includes all of the following sources except: a. Light d. Radio waves b. Microwaves e. Infrared radiation c. Ultraviolet rays f. Alpha rays

F. Alpha rays (Chapter 2-Pg.2)

8)

480. Electromagnetic waves are distinguished by their wavelength, which is expressed in ____________ or ____________, which is then expressed in hertz. a. Meters and frequency d. Feet b. Velocity and feet e. Meters and velocity c. Feet and frequency

A. Meters and frequency(Chapter 2-Pg.2)

9)

481. At one end of the electromagnetic spectrum are radio waves, which of the following is at the opposite end of the spectrum? a. Gamma rays b. Electromagnetic waves c. Thermal rays d. Alpha rays

A. Gamma rays(Chapter 2-Pg.3)

10)

482. Because of the material-based structure and small size of electronic devices, electrical power quality considerations are crucial. True or False

True(Chapter 2-Pg.3)

11)

483. Conducted coupling affect electronic devices primarily through all of the following except: a. Input signal lines b. Electromagnetic coupling c. Utility or premises electrical power distribution d. Output signal lines

B. Electromagnetic coupling(Chapter 2-Pg.3)

12)

484. Radiated interference can enter electronic devices primarily by all of the following except: a. Proximity to interfering sources b. Missing or inadequate gaskets/enclosures c. Utility or premises electrical power distribution d. Missing or inadequate bonding or earthing e. Missing or inadequate device or cable shielding

C. Utility or premises electrical power distribution(Chapter 2-Pg.3)

13)

485. Electrical codes do not generally provide for electromagnetic compatibility. True or False

True(Chapter 2-Pg.4)

14)

486. Commercial grounding and bonding standards focus on the infrastructure of a building and often do not cover: a. Tolerances related to surge current immunity and component insulation. b. Specific methods for RFI/EMI mitigation for equipment or systems c. Transient voltage surge protection on ac electrical signal paths

C. Transient voltage surge protection on ac electrical signal paths(Chapter 2-Pg.4)

15)

487. The ITS designer is directly responsible for the EMC of ITS. True or False

False(Chapter 2-Pg.4)

16)

488. MICE considerations should be considered by the designer prior to choosing the type of cabling required to support the application. True or False

True(Chapter 2-Pg.4)

17)

489. An electromagnetic field is a combination of an electrical field (created by electric currents) and magnetic field (created by stationary charges) True or False

False(Chapter 2-Pg.5)

18)

490. A magnetic field induces a voltage on a current-carrying conductor, where an electrical field induces a current on a conductor placed in its' proximity. True or False

True(Chapter 2-Pg.5)

19)

491. Electromagnetic fields can be both desirable and undesirable. True or False

True(Chapter 2-Pg.5)

20)

492. EMI sources vary greatly in the electromagnetic environment, and usually can be classified in the following categories, except for: a. Intentional d. Unintentional b. Transient e. Intransient c. Continuous

E. Intransient(Chapter 2-Pg.5)

21)

493. Control of external EMI sources is not normally practical, and internal EMI sources are usually easier to control. True or False

True(Chapter 2-Pg.6)

22)

494. Runs of unshielded and untwisted conductors in balanced twisted-pair cables are susceptible to external unwanted signal emissions because that behaves as ______________. a. Antennas b. Receivers c. Transmitters

A. Antennas(Chapter 2-Pg.6)

23)

495. The amount of radiation or coupling depends on the level of the ______________ at the output of the transmitter. a. Electromagnetic interference b. Common-mode voltage c. Digital signal processors

B. Common-mode voltage(Chapter 2-Pg.6)

24)

496. The ability to operate without introducing unwanted EMI into the environment or being affected by the internal or external unwanted signal in an undesirable way is a description of which of the following? a. Electromagnetic compatibility b. Electromagnetic interference c. Electromagnetic coupling

A. Electromagnetic compatibility(Chapter 2-Pg.8)

25)

497. Electromagnetic energy generated by equipment is frequently referred to as ____________, while the ability to withstand EM disturbances is referred to as immunity. a. Radiation b. Resistance c. Emission

C. Emission(Chapter 2-Pg.8)

26)

498. Even though there is a need for measurable parameters to establish the tests and standards used to ensure that all elements used are compatible, there are no specific techniques or units to measure EMC. True or False

True(Chapter 2-Pg.8)

27)

499. Measuring the electrical and magnetic field strength of the radiated emissions determines the outgoing radiation. True or False

False(Chapter 2-Pg.8)

28)

500. The unit of measure for the electrical field strength is all of the following except: a. Volt per meter b. Megavolts per meter c. Millivolts per meter d. Microvolt per meter

B. Megavolts per meter(Chapter 2-Pg.8)

29)

501. Measurements of conducted interference are normally taken over a frequency spectrum of ________ kHz to ________ MHz. a. 100 kHz to 30 MHz b. 200 kHz to 40 MHz c. 300 kHz to 50 MHz

A. 100 kHz to 30 MHz(Chapter 2-Pg.8)

30)

502. Measurements of radiated interference are normally taken over a frequency spectrum of _____ MHz to _____ GHz. a. 30 MHz to 5 GHz b. 40 MHz to 4 GHz c. 50 MHz to 3 GHz

A. 30 MHz to 5 GHz(Chapter 2-Pg.8)

31)

503. Which of the following is another unit often used to measure narrowband electric field strength above a reference level of microvolt? a. Decibel b. Millivolts c. Dipoles

A. Decibel(Chapter 2-Pg.8)

32)

504. The radiated interference limits are set on measurements taken by means of resonant dipoles at a distance for FCC Class B and _____ m (______ ft) for FCC Class A. a. 5 m (16.5 ft) b. 10 m (33 ft) c. 15 m (50 ft)

B. 10 m (33 ft)(Chapter 2-Pg.8)

33)

505. Methods for measurements of radiated and conducted interference include all of the following except: a. Conducted EMI from equipment b. Radiated interference measurements c. Open area test site d. Conducted interference measurements

A. Conducted EMI from equipment(Chapter 2-Pg.9)

34)

506. Some radiated interference measurements are common-mode and differential-mode interferences. True or False

False(Chapter 2-Pg.9)

35)

507. It is important to use precise terminology to avoid communication errors when using the terms EMI, EMC and RFI. True or False

True(Chapter 2-Pg.10)

36)

508. A factor that can affect EMI in TEs that would result in switched mode power supply clock signal leakage would be an issue in which of the following telecommunications equipment? a. Interconnecting cables b. Components c. Electrical power quality

C. Electrical power quality(Chapter 2-Pg.11)

37)

509. Factors such as ESD levels too low or susceptibility to pulsed EMI such as arcing, pertain to which of the following telecommunications equipment issues? a. Interconnecting cables b. Central processing unit c. Product compliance

C. Product compliance(Chapter 2-Pg.11)

38)

510. Factors that can affect EMI in TEs, where product listings are to the wrong standard or violation of listing requirements would pertain to which of the following telecommunications equipment? a. Product safety b. Installation c. OEM devices

A. Product safety(Chapter 2-Pg.12)

39)

511. Factors that can affect EMI in sites where overloaded circuits and extension cords, or improper surge protection devices would be a site issue under which of the following? a. Commercial and standby b. Branch distribution and outlets c. Electrical service entrance

B. Branch distribution and outlets(Chapter 2-Pg.13)

40)

512. All EMI problems are explainable by the basic laws of physics; the EMI problem is always a circuit. True or False

True(Chapter 2-Pg.15)

41)

513. Accomplishing EMC often involves designing for threats that may or may not occur. True or False

True(Chapter 2-Pg.15)

42)

514. EMI problems from conducted or radiated sources usually include all of the following except: a. Transmitters d. Switches b. Radar e. Receivers c. Motors

E. Receivers(Chapter 2-Pg.16)

43)

515. EMI problems from transfer or propagation sources include all of the following except: a. Space separation d. Shielding failures b. Poor filtering e. Improper grounding c. Telemetry

C. Telemetry(Chapter 2-Pg.16)

44)

516. EMI problems typically involving receiving or receptor elements include biological or human hazards. True or False

True(Chapter 2-Pg.16)

45)

517. EMI is either man-made or naturally occurring. All of the following are naturally occurring except: a. Atmospheric electricity b. Cosmic radiation c. Geothermal disturbances

C. Geothermal disturbances(Chapter 2-Pg.16)

46)

518. Of the man-made sources of EMI, engines and vehicles would be listed as being: a. Ignition systems b. Tools and machines c. Industrial and consumer equipment

A. Ignition systems(Chapter 2-Pg.17)

47)

519. Copper cables can conduct unwanted signal or radiate an electromagnetic field when attached to equipment. True or False

True(Chapter 2-Pg.18)

48)

520. The transfer of unwanted signals may occur over one path or several paths, and can transfer by all of the following ways except: a. Radiation coupling d. Conduction coupling b. Induction coupling e. Conversion coupling c. Capacitive coupling

E. Conversion coupling(Chapter 2-Pg.18)

49)

521. Some of the methods used to suppress or prevent unwanted signals include all of the following except: a. Shielding b. Induction c. Bonding and Grounding d. Filtering

B. Induction(Chapter 2-Pg.18)

50)

522. A natural phenomenon is which accumulated electrical charges are discharged is known as which of the following? a. Static discharges b. Electrostatic discharge c. Static power

B. Electrostatic discharge(Chapter 2-Pg.19)

51)

523. Which of the following is created with two materials of different dielectric constants rub against each other? a. Electrostatic discharge b. Static electric c. Electromagnetic interference

B. Static charge(Chapter 2-Pg.19)

52)

524. ESD can cause EMI. True or False

True(Chapter 2-Pg.19)

53)

525. All of the following are distinguished types of electrostatic discharge, except: a. Accumulated electrical charges b. Discharge through a spark in the air c. Contact discharge d. Radiated effects of ESD

A. Accumulated electrical charges(Chapter 2-Pg.19)

54)

526. There are four levels of immunity are outlined for contact and air discharge of ESD. True or False

True(Chapter 2-Pg.20)

55)

527. All levels of immunity are capable of inducing high-frequency electrical currents into cables in the vicinity, and can allow the current to _______ at a resonant frequency that is very low for long cables. a. Pulsate b. Ring c. Vibrate

B. Ring(Chapter 2-Pg.20)

56)

528. Which of the following devices has an electrostatic discharge susceptibility voltage range of 30 to 1800? a. Vertical metal oxide semiconductor (VMOS) b. Bipolar junction transistor (BJT) c. Silicon controlled rectifier (SCR) d. Junction gate field effect transistor (JFET)

A. Vertical metal oxide semiconductor (VMOS)(Chapter 2-Pg.21)

57)

529. Transmission lines or channels can be described in terms of distributed network parameters per unit, so generally speaking the series resistance and inductance per unit length along with the shunt capacitance and conductance per unit length can represent the wireline channel. True or False

True (Chapter 2-Pg.22)

58)

530. The value of the conductance can be assumed to be zero for a defined frequency range for several cabling systems without compromising accuracy if the dielectric material surrounding the conductor has a very good frequency response. True or False

True(Chapter 2-Pg.22)

59)

531. Which of the following can be described as disturbances created when inductive and capacitive circuits are switched on and off over an operation cycle? a. Radiated immunity b. Electrical fast transient c. Transient voltage

B. Electrical fast transient(Chapter 2-Pg.25)

60)

532. Which of the following best describes the short duration current, voltage or power on low-voltage electrical power lines? a. Radiated immunity b. Electrical fast transient c. Transient voltage

C. Transient voltage(Chapter 2-Pg.25)

61)

533. The testing of equipment for immunity to surges is complicated due to the large number of interfaces that are typical in an electronic system. True or False

True(Chapter 2-Pg.26)

62)

534. EMI and RFI are commonly used interchangeably. True or False

True(Chapter 2-Pg.27)

63)

535. Degradation of a desired signal at the receptor-end can be caused by radio frequency ranges in the ______ to ______ range. a. 10⁴ to 10⁸ range b. 10² to 10⁶ range c. 10⁵ to 10⁹ range

A. 10⁴ to 10⁸ range(Chapter 2-Pg.27)

64)

536. The only reliable and effective technique to mitigate RFI effects on telephone sets is by the deployment of shielded or screened structured cabling systems in the concerned areas. True or False

True(Chapter 2-Pg.27)

65)

537. Monitors are susceptible to RFI in certain environments and for this reason ___________ monitors are recommended for use. a. Cathode ray tube (CRT) b. Liquid crystal display (LCD) c. Thin film transistor monitors (TFT)

B. Liquid crystal display (LCD)(Chapter 2-Pg.27)

66)

538. All of the following are essentially two types of unwanted signals on cable in an EMI event, except? a. Common-mode b. Differential mode c. Predominate-mode

C. Predominate-mode(Chapter 2-Pg.28)

67)

539. Which of the types of unwanted signals below is usually predominating? a. Common-mode b. Differential mode c. Predominate-mode

A. Common-mode(Chapter 2-Pg.28)

68)

540. Which of the types of unwanted signals are coupled into a pair of conductors due to radiation from an EMI source? a. Common-mode b. Differential mode c. Predominate-mode

B. Differential mode(Chapter 2-Pg.28)

69)

541. Twisting the conductors in pairs can minimize differential mode interference. True or False

True(Chapter 2-Pg.28)

70)

542. In order to successfully filter both types of unwanted signals, a _____________ is preferred. a. Magnetic conductor b. Magnetic filter c. Magnetic scheme

C. Magnetic scheme(Chapter 2-Pg.28)

71)

543. Unwanted DM signal mitigation can be accomplished using individual ____________ installed on each input lead of the line or output lead of the interfering circuit or line. a. Ferrite beads b. Glass beads c. Filtering beads

A. Ferrite beads(Chapter 2-Pg.28)

72)

544. Common-mode unwanted signals on cabling can affect equipment, such as locking up a computer, because the CM signal gets inside the equipment and causes logical errors. Which of the following is NOT a problem with CM unwanted signals? a. Occurs equally and in phase on all signal lines with relationship to the reference ground b. CM signal can become converted to a DM signal by cable or equipment c. Affects equipment by corrupting transmitted signals on a balanced circuit.

C. Affects equipment by corrupting transmitted signals on a balanced circuit.(Chapter 2-Pg.28)

73)

545. Differential-mode noise can affect equipment by corrupting transmitted signals on a balanced circuit. This DM noise can also be a result of coupling between two or more pairs inside a balanced cable. True or False

True(Chapter 2-Pg.29)

74)

546. A source of unwanted signals, electrical power converters typically produce ___________ signals. a. Common-mode b. Differential-mode c. Both of the above

C. Both of the above(Chapter 2-Pg.30)

75)

547. The logic circuits of telecommunications systems can be another source of unwanted signal as it introduces the unwanted signal directly to both the ground plane and the dc power supply, which can affect the entire electrical system. True or False

True(Chapter 2-Pg.30)

76)

548. Semiconductor unwanted signals can propagate to logic lines, to and from digital system clocks and onto data lines. True or False

True(Chapter 2-Pg.30)

77)

549. High-frequency unwanted signals may be coupled on the electrical power line without affecting the electrical power circuitry. True or False

True(Chapter 2-Pg.30)

78)

550. Cables are seldom the longest paths between circuit components and modules. True or False

False(Chapter 2-Pg.30)

79)

551. All of the following are considered important items of consideration when designing a cabling system for EMC, except: a. Use of shielded cable d. Availability of structural steel in the building b. Use of surge protection e. Bonding infrastructure for EFs, ERs, and TRs c. Existing CM or DM f. dc grounding electrode system disturbance levels design

F. dc grounding electrode system design(Chapter 2-Pg.31)

80)

552. Which of the following terms best describes two parallel paths that have identical conductive terminations to two separate grounding references? a. Common-mode interference d. Bonding infrastructure b. Differential-mode interference e. None of the above c. Ground loops

C. Ground loops(Chapter 2-Pg.31)

81)

552. Which of the following terms best describes two parallel paths that have identical conductive terminations to two separate grounding references? a. Common-mode interference d. Bonding infrastructure b. Differential-mode interference e. None of the above c. Ground loops

C. Ground loops(Chapter 2-Pg.31)

82)

553. At low frequencies, cable shield can be grounded at one cable end and provide effective resistance to the effects EMI. True or False

True(Chapter 2-Pg.32)

83)

554. There are several standards for bonding and grounding, and different requirements, but that difference should not be higher than _____ V rms to minimize ground loop effects. a. 1 V rms b. 3 V rms c. 5 V rms

A. 1 V rms(Chapter 2-Pg.32)

84)

555. It is mandatory to guarantee minimum potential differences between both ground connections. True or False

True(Chapter 2-Pg.32)

85)

556. Also important to consider is that at higher frequencies, there is a _______________ coupling that tends to complete the ground loop when the cable shield is grounded at one cable end only. a. Unwanted signal b. Stray capacitive coupling c. Radiation coupling

B. Stray capacitive coupling(Chapter 2-Pg.33)

86)

557. Where does the grounding electrode conductor ground the electrical power distribution circuit that serves the ac source for building system and telecommunications? a. In the telecommunications room b. At the equipment grounding point c. At the service entrance

C. At the service entrance(Chapter 2-Pg.34)

87)

558. Which of the following would be the accurate equation to get the magnitude of the volts in decibel relative to 1 V for a circular loop antenna? a. Vcn = 2πΕϜ/λ b. Vdm = 2πΕΕ/λ c. Vcm = 2πΑΕ/λ

C. Vcm = 2πΑΕ/λ(Chapter 2-Pg.36)

88)

559. Changing the average height from 1 m (3 ft) to 100 mm (4 in) reduces the unwanted signal coupling by a factor of ______. a. 5 b. 10 c. 15

B. 19(Chapter 2-Pg.36)

89)

560. Metallic conduit can be used to minimize the accumulation of voltages, it can also be used for all of the following except: a. Reduce common-mode field to loop EMI b. Reduce common-mode crosstalk c. Create a reference ground plane d. Reduce capacitances

D. Reduce capacitances(Chapter 2-Pg.36)

90)

561. Metallic cable raceways can be connected directly to the equipment structure, or chassis, or by means of a jumper. True or False

True(Chapter 2-Pg.37)

91)

562. In general, instrumentation shields should only be grounded at one end, but for longer runs and interfacility runs, cable shields are generally grounded at each end. True or False

True(Chapter 2-Pg.38)

92)

563. Electromagnetic shielding can be used to minimize the level of radiation from a given system into its environment. True of False

True(Chapter 2-Pg.38)

93)

564. At lower frequencies, cable twists absorb the major part of the EMI effects; at higher frequencies the ___________ absorbs the electromagnetic waves. a. Conduit b. Cable tray c. Cable shield

C. Cable shield(Chapter 2-Pg.38)

94)

565. The transmission of electromagnetic energy into another form, usually thermal, is a good description of which of the following? a. Absorption loss b. Transference loss c. Conductivity loss

A. Absorption loss(Chapter 2-Pg.39)

95)

566. Transfer impedance is a measure of the voltage induced on the inside surface of a shield for a current flowing on the outside surface of the shield. True or False

True(Chapter 2-Pg.39)

96)

567. Shield effectiveness varies with all of the following except: a. Operating frequency b. Type, thickness and geometry of the shielding materials c. Method of grounding d. Type and quality of cable used

D. Type and quality of cable used(Chapter 2-Pg.39)

97)

568. Shield discontinuities can adversely affect the shielding effectiveness. True or False

True(Chapter 2-Pg.39)

98)

569. The successful termination of shielded/screened cables into connectors requires good connection between the cable screen and the connector metallic body. True or False

True(Chapter 2-Pg.39)

99)

570. Grounding of cable shields must be made using a _______ degree connection avoiding any breaches in the conductor continuity. a. 160° b. 360° c. 45°

B. 360°(Chapter 2-Pg.39)

100)

571. When designing telecommunications systems, regulations typically relate to an electronic system as a whole and not to any specific component. True or False

True(Chapter 2-Pg.40)

101)

572. When designing a cabling system for critical environments in terms of EMI, the designer "Shall or Should" follow cable separation guidelines? Shall or Should

Shall(Chapter 2-Pg.40)

102)

573. All of the following are likely sources of EMI, except: a. Electric motors d. Door openers b. Fluorescent lighting e. Copiers c. Electrical power cables f. Computers

F. Computers(Chapter 2-Pg.40)

103)

574. Performance-enhanced balanced twisted-pair cables offer some degree of unwanted signal rejection that makes shielding unnecessary in most of the commercial environments. True or False

True(Chapter 2-Pg.40)

104)

575. The use of __________ is one way to limit inductive unwanted signal coupling between the telecommunications cabling and potential sources of EMI. a. Metallic connector gaskets b. Instrumentation shields c. Grounded metallic pathways

C. Grounded metallic pathways(Chapter 2-Pg.41)

105)

576. The use of sheathed cables or other branch circuit cable constructions that prevent separation of the line, neutral and grounding conductors also minimize EMI emission from electrical power conductors. True or False

True(Chapter 2-Pg.41)

106)

577. Higher-balanced twisted-pair cable categories result in better noise rejection response. True or False

True(Chapter 2-Pg.41)

107)

578. Multiple conductor cable used for transmission of several individual signals should consist of balanced twisted-pair signal conductors with the same twists. True or False

False(Chapter 2-Pg.42)

108)

579. Low-level data transmission lines should not be run parallel to high-level electrical power lines. True or False

True(Chapter 2-Pg.42)

109)

580. Where cables of different signal conditions must cross, crossing should be at a _______ degree angle. a. 45 degree b. 90 degree c. 180 degree

B. 90 degree(Chapter 2-Pg.42)

110)

581. Signal conductors "Shall not or Should not" be installed into conduit containing electrical power conductors. Shall not or Should not

Shall not(Chapter 2-Pg.42)

111)

582. The use of _______ devices should be used to reduce transients that emanate from inductive devices that are being switched off. a. Surge protectors b. EMI filter c. Capacitor

A. Surge protectors(Chapter 2-Pg.43)

112)

583. Whenever possible sources of EMI exceeding 5 kVA, should be kept physically separated from telecommunications cables, but less than 5 kVA, no additional separation should be necessary. True or False

True(Chapter 2-Pg.44)

113)

584. High levels of noise on power branch circuits is abnormal and unacceptable, and should be corrected or suppressed by using all of the following, except: a. Circuit protectors b. Line conditioners c. Surge protectors

A. Circuit protectors(Chapter 2-Pg.44)

114)

585. Optical fiber is immune to the effects of EMI. True or False

True(Chapter 2-Pg.44)

115)

586. The minimum separation distance from possible sources of EMI exceeding 5 kVA for unshielded power lines or electrical equipment in proximity to open or non-metal pathway is: a. 150 mm (6 in) b. 300 mm (12 in) c. 610 mm (24 in)

C. 610 mm (24 in)(Chapter 2-Pg.44)

116)

587. The minimum separation distance from possible sources of EMI 5 kVA for electrical motors and transformers is: a. 1000 mm (39 in) b. 1194 mm (47 in) c. 1521 mm (60 in)

B. 1194 mm (47 in)(Chapter 2-Pg.44)

117)

588. The minimum separation requirements between metallic cabling and fluorescent, neon, mercury vapor and high-intensity discharge lamps are all the same at _____mm (_____ in), but can be reduced the appropriate cable management systems are used or product suppliers guarantees are provided. a. 130 mm (5.12 in) b. 260 mm (10.24 in) c. 390 mm (15.36 in)

A. 130 mm (5.12 in)(Chapter 2-Pg.44)

118)

589. The minimum separation requirements between metallic cabling and frequency induction heating is which of the following? a. 390 mm (15.36 in) b. 780 mm (27.2 in) c. 1000 mm (39.37 in)

C. 1000 mm (39.37 in)(Chapter 2-Pg.44)

119)

590. An electrical power line EMI filter is "mandatory / not mandatory" in all modern electronics? Mandatory or Not Mandatory

Mandatory(Chapter 2-Pg.45)

120)

591. A successful data line filtering scheme must provide for effective attenuation of high-frequency unwanted signals, as well as broadband CM unwanted signal and provide for the maintenance of signal integrity. True or False

True(Chapter 2-Pg.46)

121)

592. Isolation transformers for data signals are quite strict as they are narrowband devices and must provide isolation with a narrow frequency. True or False

False(Chapter 2-Pg.46)

122)

593. The function of isolation transformers is primarily to interrupt the CM ground loop at the receiver or transmitter end. True or False

True(Chapter 2-Pg.46)

123)

594. The primary to secondary capacitance tends to close the ground loop across a barrier, which leads the system to an unbalance and some of the CM voltage is transferred to the secondary of the transformer as DM noise. This transfer is known as which of the following? a. Mode conversion b. Primary conversion c. Secondary conversion

A. Mode conversion(Chapter 2-Pg.46)

124)

595. All of the following are efficient components to mitigate electromagnetic interference problems, except: a. Ferrite beads b. Ferrite sleeves c. Ferrite connectors d. Ferrite toroids

C. Ferrite connectors(Chapter 2-Pg.47)

125)

596. Ferrites can also be used when the cable shield currents need to be reduced without shield interruption. True or False

True(Chapter 2-Pg.47)

126)

598. A decrease in the electrical power of the interfering signals by as little as _____ times can make a remarkable difference in the performance of the telecommunications system. a. 3 times b. 5 times c. 10 times

C. 10 times(Chapter 2-Pg.48)

127)

599. Equal currents flowing in each half of the primary winding of a well balanced transformer produces equal and opposite voltages at the secondary winding. True or False

True(Chapter 2-Pg.49)

128)

600. A minimum common-mode rejection ratio of ______ dB is desirable for high-quality chokes over the operating frequency range of interest. a. 20 dB b. 30 dB c. 40 dB

C. 40 dB(Chapter 2-Pg.49)

129)

601. Depending upon the degree of unbalance, part of a CM unwanted signal is converted to a DM unwanted signal that can pass directly to the receiver. Which of the following is a measure of this conversion? a. Longitudinal conversion transfer loss b. Low voltage disconnect transfer loss c. Longitudinal noise transfer loss

A. Longitudinal conversion transfer loss(Chapter 2-Pg.50)

130)

602. All of the following are major components of the electromagnetically induced interference that relates to telephone transmission facilities placed in a joint-use tunnel with an electrical power system, except: a. Susceptibility of the telecommunications system b. Current that propagates over the power cable c. Coupling between the electrical power and telecommunications system d. Induced electromagnetic fields from the electrical power system

B. Current that propagates over the power cable(Chapter 2-Pg.51)

131)

603. The magnitude of the electrical power line influence is determined by the magnitude of all of the following, except: a. Physical configuration of the line b. Current that propagates over the power cable c. Shielding effectiveness

C. Shielding effectiveness(Chapter 2-Pg.51)

132)

604. Coupling form mutual capacitance and/or mutual inductance between the electrical power and telephone/telecom facilities is a function of all of the following except: a. Physical separation between facilities b. Length of exposure or parallel cables c. Impedance of the return path d. Physical configuration of the system

D. Physical configuration of the system(Chapter 2-Pg.51)

133)

605. To reduce coupling in a tunnel, shielding on either facility where appropriate, can reduce coupling. True or False

True(Chapter 2-Pg.51)

134)

606. Safety considerations "Require / Recommend" that the chassis, or metal enclosures, for electrical equipment be grounded at each end of the cable. Require or Recommend

Require(Chapter 2-Pg.53)

135)

607. It is "Required / Recommended" to ground shielded cabling systems at both cable ends because of the instability of the stray capacitance value along a wide frequency range. Required or Recommended

Recommended(Chapter 2-Pg.54)

136)

608. Which of the following are characteristics of the telephone and telecom circuits that determine susceptibility or the extent the circuit is adversely affected by inductive fields? a. Amount or presence of shielding provided b. Balance of the telephone/telecom circuit c. Potential difference between grounds

C. Potential difference between grounds(Chapter 2-Pg.55)

137)

609. The worst offenders in terms of unwanted signals are high-frequency transients generated by starting and stopping machinery. True or False

True(Chapter 2-Pg.55)

138)

610. Potential difference between any two grounds "Shall / Should" be no more than 1.0 V rms to avoid any problems with conductive group loops. Shall / Should

Shall(Chapter 2-Pg.55)

139)

611. RMS power is ultimately the average of an ac waveform, which is the peak voltage, multiplied by __________. a. 0.505 b. 0.606 c. 0.707

C. 0.707(Chapter 2-Pg.55)

140)

612. It is recommended to use an overall longitudinal balance of ______ dB or greater at low frequencies and 30 to 40 dB or greater at high frequencies. a. 50 dB b. 60 dB c. 70 dB

B. 60 dB(Chapter 2-Pg.55)