RCDD Chapter 2 Electromagnetic Compatibility Quiz
What does RCDD stand for? Can you pass this RCDD chapter 2 electromagnetic compatibility quiz? RCDD stands for Registered Communications Distribution Designer. It is an accomplished professional who has gained the status of exceptional excellence in the ICT (Information and Communications Technology) industry which is given by BICSI (Building Industry Consulting International). So, let's take some questions and see if you can score high. Wish you good luck, and we hope you enjoy your time playing this quiz.
Questions and Answers
- 1.
Radiated emissions are determined by measuring the field strength of the outgoing radiation. The unit of measure is what?
- A.
Volts
- B.
Amps
- C.
Volts per Amps V/a
- D.
Volts per meter V/m
Correct Answer
D. Volts per meter V/mExplanation
Radiated emissions are measured in volts per meter (V/m). This unit of measure quantifies the strength of the electromagnetic field being emitted from a source. It indicates the electric field strength at a specific distance from the source. By measuring the field strength, one can assess the level of electromagnetic interference and determine if it complies with regulatory standards. Therefore, V/m is the appropriate unit for measuring radiated emissions.Rate this question:
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- 2.
Site issues such as telephone distribution, what are the EMI factors
- A.
Unbalanced cabling
- B.
Incorrect or missing primary protectors
- C.
Incompatible secondary protectors
- D.
Incorrect or missing grounds
- E.
Incorrect or missing connections
Correct Answer(s)
A. Unbalanced cabling
B. Incorrect or missing primary protectors
C. Incompatible secondary protectors
D. Incorrect or missing grounds
E. Incorrect or missing connectionsExplanation
The correct answer includes various factors that can contribute to site issues such as telephone distribution. Unbalanced cabling refers to cables that have unequal impedance, which can cause signal distortion and interference. Incorrect or missing primary protectors can leave the system vulnerable to power surges and other electrical disturbances. Incompatible secondary protectors may not provide adequate protection for the system. Incorrect or missing grounds can result in electrical instability and potential safety hazards. Incorrect or missing connections can lead to signal loss and poor performance. All of these factors can contribute to site issues with telephone distribution.Rate this question:
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- 3.
All EMI problems are explainable by the basic laws of physics, and the EMI problem is always a circuit.
- A.
True
- B.
False
Correct Answer
A. TrueExplanation
This statement is true because EMI (Electromagnetic Interference) problems can be explained and understood using the fundamental laws of physics. EMI occurs when electromagnetic waves interfere with the normal operation of electronic devices or circuits. Since electromagnetic waves are governed by the laws of physics, understanding these laws helps in identifying the causes and finding solutions to EMI problems. Additionally, EMI problems are always related to circuits because they involve the interaction of electromagnetic waves with electronic components and circuits.Rate this question:
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- 4.
Contact discharges level number X 2 will give you your voltage level.
- A.
True
- B.
False
Correct Answer
A. TrueExplanation
The given statement suggests that multiplying the contact discharges level number by 2 will give the voltage level. This implies that there is a direct relationship between the contact discharges level and the voltage level. Therefore, the statement is true.Rate this question:
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- 5.
Sources of the unwanted signal are what?
- A.
Electrical power converters
- B.
Logic Circuits
- C.
Other Internal unwanted Signal
- D.
Electrical power line
- E.
Cabling
Correct Answer(s)
A. Electrical power converters
B. Logic Circuits
C. Other Internal unwanted Signal
D. Electrical power line
E. CablingExplanation
The sources of unwanted signals can include electrical power converters, logic circuits, other internal unwanted signals, electrical power lines, and cabling. These sources can introduce noise or interference into a system, affecting the quality and reliability of the desired signals.Rate this question:
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- 6.
At the services entrance, what grounds the electrical power?
- A.
Grounding electrode conductor
- B.
Grounding electrode
- C.
Building conductor for telecommunications
- D.
Telecommunications bonding backbone
- E.
The main grounding busbar
Correct Answer
A. Grounding electrode conductorExplanation
The grounding electrode conductor is responsible for grounding the electrical power at the services entrance. It provides a safe path for electrical current to flow into the ground in the event of a fault or surge, protecting the electrical system and preventing potential hazards such as electric shocks or fires. By connecting the grounding electrode to the electrical system, the grounding electrode conductor ensures that any excess electrical energy is safely discharged into the ground.Rate this question:
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- 7.
Which major components do not belong when dealing with electromagnetically induced interference?
- A.
Unbalanced EM fields of the electrical power system
- B.
Balanced DM field of the electrical power system
- C.
Coupling between the electrical power and telecommunications systems
- D.
The susceptibility of the telecommunications systems
Correct Answer
B. Balanced DM field of the electrical power systemExplanation
The major components that do not belong when dealing with electromagnetically induced interference are the "Balanced DM field of the electrical power system." Electromagnetic interference is caused by unbalanced EM fields of the electrical power system, coupling between the electrical power and telecommunications systems, and the susceptibility of the telecommunications systems. The balanced DM field does not contribute to electromagnetic interference.Rate this question:
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- 8.
The recommendation is to use an overall longitudinal balance of _____ or greater at low frequencies.
- A.
30db
- B.
20db
- C.
50db
- D.
60db
Correct Answer
D. 60dbExplanation
The recommendation is to use an overall longitudinal balance of 60db or greater at low frequencies. This means that the balance between the longitudinal signals should be at least 60db or higher to achieve optimal performance at low frequencies. This ensures that the signals are evenly distributed and minimizes any potential interference or distortion that may occur.Rate this question:
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- 9.
The EM energy generated by equipment is commonly referred to as immunity, and the equipment's ability to withstand EM disturbances is referred to as emissions.
- A.
True
- B.
False
Correct Answer
B. FalseExplanation
The statement is incorrect. The EM energy generated by equipment is commonly referred to as emissions, not immunity. Immunity refers to the equipment's ability to withstand EM disturbances.Rate this question:
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- 10.
Internal EMI sources are usually harder to control since it is not possible to reduce the emissions at the source.
- A.
True
- B.
False
Correct Answer
B. FalseExplanation
The statement is false because it is possible to control internal EMI sources by reducing emissions at the source. This can be achieved through various methods such as shielding, grounding, and filtering. By implementing these measures, the emissions from internal sources can be minimized and controlled effectively.Rate this question:
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- 11.
External EMI sources are typical
- A.
Cellular phones
- B.
Electrical power cables
- C.
Rectifiers
- D.
Radio
Correct Answer
A. Cellular phonesExplanation
Cellular phones are a typical source of external electromagnetic interference (EMI). This is because they emit radio waves and electromagnetic signals that can interfere with other electronic devices. The signals from cellular phones can disrupt the functioning of nearby devices, causing interference or noise in their operation. Therefore, cellular phones are considered one of the common sources of EMI in various environments.Rate this question:
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- 12.
Electromagnetic EM includes light, radio waves, microwaves, infrared IR radiation, ultraviolet rays, X-rays, and gamma rays. What are these Collectively known as?
- A.
Electrical protection
- B.
Input signal lines
- C.
EM spectrum
- D.
Output signals
Correct Answer
C. EM spectrumExplanation
The given correct answer is "EM spectrum". The question asks about the collective name for various types of electromagnetic waves, including light, radio waves, microwaves, infrared radiation, ultraviolet rays, X-rays, and gamma rays. These waves collectively form the electromagnetic spectrum, which encompasses the entire range of electromagnetic radiation.Rate this question:
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- 13.
Magnetic beads are often used for filtering, and more than one bead may be required.
- A.
True
- B.
False
Correct Answer
A. TrueExplanation
Magnetic beads are commonly used for filtering because they can easily be manipulated using a magnetic field. Their magnetic properties allow them to attract and bind to specific molecules or particles, making them effective for separating and purifying substances in various applications such as biological research, diagnostics, and industrial processes. Since the amount of material to be filtered may vary, it is possible that more than one magnetic bead is needed to achieve the desired level of filtration. Therefore, the statement that more than one bead may be required for filtering is true.Rate this question:
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- 14.
Many of the same considerations that apply to balanced twisted-pair cables concerning unwanted signal coupling apply to screened or foil twisted-pair (SCTP or FTP) cables.
- A.
True
- B.
False
Correct Answer
A. TrueExplanation
Screened or foil twisted-pair (SCTP or FTP) cables have similar considerations as balanced twisted-pair cables when it comes to unwanted signal coupling. This means that the same factors that affect the interference and noise in balanced twisted-pair cables also apply to SCTP or FTP cables. Therefore, the statement "Many of the same considerations that apply to balanced twisted-pair cables concerning unwanted signal coupling apply to screened or foil twisted-pair (SCTP or FTP) cables" is true.Rate this question:
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- 15.
It's ok to place telecommunications systems next to equipment that can generate EMI.
- A.
True
- B.
False
Correct Answer
B. FalseExplanation
Placing telecommunications systems next to equipment that can generate electromagnetic interference (EMI) is not okay. EMI can disrupt the functioning of telecommunications systems, leading to poor signal quality, dropped calls, and other communication issues. To ensure optimal performance and minimize interference, it is recommended to keep telecommunications systems away from EMI-generating equipment.Rate this question:
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- 16.
The coupling from mutual impedance between the electrical power and telephone facility is a function of the following: Please identify the one that does not belong.
- A.
Physical separation between the electrical power and telephone facilities.
- B.
Length of exposure.
- C.
Resistance to the return path for the unbalanced current.
- D.
Signal injectors
- E.
Shielding effectiveness of the electrical power and telephone cables.
Correct Answer
D. Signal injectors -
- 17.
DM noise affects equipment primarily by corrupting transmitted signals on an unbalanced circuit.
- A.
Ture
- B.
False
Correct Answer
B. FalseExplanation
DM noise, also known as common mode noise, affects equipment primarily by corrupting transmitted signals on a balanced circuit, not an unbalanced circuit. In an unbalanced circuit, noise affects both the signal and the common ground reference, resulting in signal corruption. Therefore, the given statement is false.Rate this question:
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- 18.
The unwanted signal is comprised of two components CM unwanted signal and DM unwanted signal.
- A.
True
- B.
False
Correct Answer
A. TrueExplanation
The explanation for the given correct answer is that the unwanted signal consists of two components: CM unwanted signal and DM unwanted signal. This means that there are two types of unwanted signals present, namely common-mode (CM) unwanted signal and differential-mode (DM) unwanted signal. Therefore, the statement "The unwanted signal is comprised of two components CM unwanted signal and DM unwanted signal" is true.Rate this question:
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- 19.
Radio Frequency Immunity is generally stated at ________volts root-mean-spuare (Vrms)
- A.
1
- B.
2
- C.
3
- D.
10
- E.
5
Correct Answer
C. 3Explanation
Radio Frequency Immunity is generally stated at 3 volts root-mean-square (Vrms).Rate this question:
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- 20.
What are two types of unwanted signals on a cable?
- A.
Common Mode (CD)
- B.
Current
- C.
Unwanted signal
- D.
Differential Mode (DM)
Correct Answer(s)
A. Common Mode (CD)
D. Differential Mode (DM)Explanation
Common Mode (CD) and Differential Mode (DM) are two types of unwanted signals on a cable. Common Mode (CD) refers to the unwanted signal that appears in phase and at the same amplitude on both conductors of the cable, while Differential Mode (DM) refers to the unwanted signal that appears out of phase and with different amplitudes on the two conductors of the cable. These unwanted signals can cause interference and degrade the quality of the desired signal being transmitted through the cable.Rate this question:
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- 21.
In the balance of twisted pair cabling, the CM rejection of the magnetics can be further improved by adding a CM choke in series with the transformer. A minimum common-mode rejection ratio (CMRR) of __________ is desirable for high-quality magnetics over the operating frequency range of interest.
- A.
30 dB
- B.
20 dB
- C.
40 dB
- D.
60 dB
- E.
50 dB
Correct Answer
C. 40 dBExplanation
Adding a CM choke in series with the transformer helps to improve the CM rejection of the magnetics in twisted pair cabling. The minimum desired common-mode rejection ratio (CMRR) for high-quality magnetics over the operating frequency range of interest is 40 dB. This means that the magnetics should be able to attenuate common-mode noise by at least 40 decibels, providing a high level of rejection and ensuring better signal quality.Rate this question:
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- 22.
EMI is man-made or naturally occurring?
- A.
True
- B.
False
Correct Answer
A. TrueExplanation
EMI stands for Electromagnetic Interference, which refers to the disturbance caused by electromagnetic radiation on electronic devices or systems. EMI can be both man-made and naturally occurring. Man-made sources of EMI include electrical appliances, power lines, and electronic devices. On the other hand, naturally occurring sources of EMI include lightning and cosmic radiation. Therefore, the statement "EMI is man-made or naturally occurring?" is true, as EMI can originate from both man-made and natural sources.Rate this question:
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- 23.
Electromagnetic (EM) includes light, radio waves, microwaves, infrared (IR)radiation, ultraviolet rays, X-rays, and gamma rays. These are also known collectively as the EM Spectrum and are fundamentally similar in that they travel at the speed of light.
- A.
False
- B.
True
Correct Answer
B. TrueExplanation
The given statement is true. Electromagnetic waves, including light, radio waves, microwaves, infrared radiation, ultraviolet rays, X-rays, and gamma rays, are all part of the electromagnetic spectrum. These waves all travel at the speed of light, making them fundamentally similar. Therefore, the statement is correct.Rate this question:
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- 24.
Man-made sources of EMI include what?
- A.
Conversion (step up/down)
- B.
Distribution (insulation, cabling, transformers, or grounding)
- C.
Generators
- D.
Cell phones
- E.
RF
Correct Answer(s)
A. Conversion (step up/down)
B. Distribution (insulation, cabling, transformers, or grounding)
C. GeneratorsExplanation
Man-made sources of EMI include conversion (step up/down), distribution (insulation, cabling, transformers, or grounding), and generators. These sources can produce electromagnetic interference, which refers to the disturbance caused by electromagnetic radiation from electronic devices. Conversion processes, such as step up/down transformers, can generate EMI due to the switching of electrical currents. Distribution systems, including insulation, cabling, transformers, and grounding, can also produce EMI if not properly designed or maintained. Additionally, generators, which produce electrical power, can be a source of EMI if not adequately shielded or grounded.Rate this question:
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