3D153 CDC Vol. 1
- 1.
Which of the following is not a function of the sections within the career field training plan (CFETP) part I?
- A.
Indicates source restraints.
- B.
Identifies the specialty training standard (STS).
- C.
Explains the purpose of the CFETP and how it is to be used.
- D.
Identifies duties and responsibilities, skill and career progression, and career field path.
Correct Answer
B. Identifies the specialty training standard (STS).Explanation
The correct answer is "Identifies the specialty training standard (STS)." The other options listed are all functions of the sections within the career field training plan (CFETP) part I. The CFETP is designed to provide guidance and structure for career field training and development. It includes information on source restraints, the purpose of the CFETP and how it should be used, as well as identifying duties and responsibilities, skill and career progression, and the career field path. However, identifying the specialty training standard (STS) is not one of the functions of the CFETP.Rate this question:
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- 2.
Which of the following is not a requirement for upgrade to 3D153?
- A.
Obtaining flight chief approval for the award of Air Force Specialty Code (AFSC) 3D153.
- B.
Completing Cyberspace Support career development course (CDC) 3DX5X.
- C.
Completing Radio Frequency (RF) Transmission Systems CDC 3D153.
- D.
Completing all core tasks identified for 5 skill-level.
Correct Answer
A. Obtaining flight chief approval for the award of Air Force Specialty Code (AFSC) 3D153.Explanation
To upgrade to 3D153, one must complete the Cyberspace Support career development course (CDC) 3DX5X, complete the Radio Frequency (RF) Transmission Systems CDC 3D153, and complete all core tasks identified for the 5 skill-level. Obtaining flight chief approval for the award of Air Force Specialty Code (AFSC) 3D153 is not mentioned as a requirement.Rate this question:
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- 3.
Which 3D career field installs, supports, and maintains servers or other computer systems and responds to service outages and interruptions to network operations?
- A.
Knowledge Operations Management (3D0X1)
- B.
Cyber Systems Operations (3D0X2)
- C.
Spectrum Operations (3D1X2)
- D.
Cyber Surety (3D0X3)
Correct Answer
B. Cyber Systems Operations (3D0X2)Explanation
Cyber Systems Operations (3D0X2) is the correct answer because this career field involves installing, supporting, and maintaining servers or other computer systems. It also includes responding to service outages and interruptions to network operations. This job requires knowledge and skills in managing and troubleshooting computer systems and networks, ensuring their smooth operation and addressing any issues that may arise.Rate this question:
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- 4.
Which 3D career field deploys, sustains, troubleshoots and repairs voice, data and video network infrastructure systems, Internet Protocol (IP) detection systems and cryptographic equipment?
- A.
Radio Frequency Transmissions Systems (3D1X3)
- B.
Cyber Transport Systems (3D1X2)
- C.
Spectrum Operations (3D1X4)
- D.
Client Systems (3D1X1)
Correct Answer
B. Cyber Transport Systems (3D1X2)Explanation
Cyber Transport Systems (3D1X2) is the correct answer because this career field involves deploying, sustaining, troubleshooting, and repairing voice, data, and video network infrastructure systems, as well as IP detection systems and cryptographic equipment. This field deals with the management and maintenance of network systems and ensures their proper functioning and security.Rate this question:
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- 5.
What outlines mandatory training items that supervisors use to prepare job safety training guides (JSTG)?
- A.
Air Force Safety Outline (AFSO)
- B.
Air Force Safety Instruction (AFSI)
- C.
Job Safety Training Outline (JSTO)
- D.
Job Safety Training Instruction (JSTI)
Correct Answer
C. Job Safety Training Outline (JSTO)Explanation
The correct answer is Job Safety Training Outline (JSTO). This is because the JSTO is specifically designed to outline the mandatory training items that supervisors use to prepare job safety training guides (JSTG). The JSTO provides a structured framework for supervisors to ensure that all necessary training topics are covered in their guides, helping to promote a safe working environment. The other options, such as the Air Force Safety Outline (AFSO) and Air Force Safety Instruction (AFSI), may be related to safety but do not specifically address the preparation of job safety training guides. The Job Safety Training Instruction (JSTI) is not mentioned in the question and therefore cannot be considered as the correct answer.Rate this question:
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- 6.
Which AF Form is used to report hazardous conditions that place Air Force personnel or property at risk?
- A.
1118
- B.
457
- C.
55
- D.
3
Correct Answer
B. 457Explanation
AF Form 457 is used to report hazardous conditions that place Air Force personnel or property at risk. This form is specifically designed for reporting unsafe conditions or practices in order to prevent accidents or damage. By reporting these hazards, the Air Force can take appropriate measures to mitigate the risks and ensure the safety of its personnel and property.Rate this question:
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- 7.
Which hazard is cause by heavy workloads, lack of control over the pace of work, shift work, noise, working by yourself, and conflict with coworkers and employers?
- A.
Biological
- B.
Chemical
- C.
Physical
- D.
Stress
Correct Answer
D. StressExplanation
Stress is caused by heavy workloads, lack of control over the pace of work, shift work, noise, working by yourself, and conflict with coworkers and employers. These factors can lead to increased levels of stress, which can have negative effects on an individual's physical and mental health.Rate this question:
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- 8.
Which Air Force program provides a means of reporting hazards that involve flight, ground, weapons, or space safety?
- A.
Ground safety program
- B.
Hazard reporting program
- C.
Hazard communication program
- D.
Ground safety mishap prevention program
Correct Answer
B. Hazard reporting programExplanation
The correct answer is Hazard reporting program. This program provides a means for reporting any hazards that involve flight, ground, weapons, or space safety. It allows individuals to report any potential dangers or risks that they observe, ensuring that they are addressed and mitigated to maintain a safe environment for all operations.Rate this question:
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- 9.
To prevent manual handling hazards, utilize team lifting when items that weigh more than how many pounds?
- A.
25
- B.
50
- C.
75
- D.
100
Correct Answer
A. 25Explanation
To prevent manual handling hazards, team lifting should be utilized when items weigh more than 25 pounds. This means that when an object weighs more than 25 pounds, it is recommended to have multiple people lift it together to distribute the weight and reduce the risk of injury or strain. This practice helps to ensure the safety of individuals involved in manual handling tasks and prevents accidents or health issues that can arise from lifting heavy objects alone.Rate this question:
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- 10.
The minimum milliamperes (mA) of current that result in cardiac arrest and can cause death is
- A.
100 mA
- B.
75 mA
- C.
50 mA
- D.
25 mA
Correct Answer
C. 50 mAExplanation
A current of 50 mA is considered the minimum amount that can result in cardiac arrest and potentially cause death. This level of current is enough to disrupt the normal electrical signals in the heart, leading to an irregular heartbeat and potentially stopping the heart altogether. It is important to note that individual susceptibility to electric shock may vary, and factors such as the path of the current, duration of exposure, and overall health can also influence the severity of the effects.Rate this question:
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- 11.
Within how many hours must a medical exam be concluded if non-ionizing radiation overexposure occurs?
- A.
24
- B.
48
- C.
72
- D.
96
Correct Answer
C. 72Explanation
If non-ionizing radiation overexposure occurs, a medical exam must be concluded within 72 hours. This is important because non-ionizing radiation can have harmful effects on the body, and prompt medical attention is necessary to assess the extent of the overexposure and provide appropriate treatment if needed. Waiting longer than 72 hours may result in delayed diagnosis and potential complications.Rate this question:
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- 12.
Which technical order (TO) publication series cover standard Air Force installation practices?
- A.
TO 31-20 series
- B.
TO 61-20 series
- C.
TO 31-10 series
- D.
TO 61-10 series
Correct Answer
C. TO 31-10 seriesExplanation
The correct answer is TO 31-10 series. This series of technical order publications covers standard Air Force installation practices.Rate this question:
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- 13.
Which section of a horizontal cable duct is used for signal and control cables?
- A.
Lower
- B.
Upper
- C.
Right
- D.
Left
Correct Answer
B. UpperExplanation
The upper section of a horizontal cable duct is typically used for signal and control cables. This section is usually designated for these types of cables to ensure proper organization and separation from other types of cables. By placing signal and control cables in the upper section, it helps to minimize interference and maintain the integrity of the signals being transmitted.Rate this question:
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- 14.
How are connectorized cables labled?
- A.
The first label is placed within 6 inches of the connector and marked "TO", and the second is placed within one (1) inch of the first label and marked "FROM".
- B.
The first label is placed within 6 inches of the connector and marked "TO", and the second is placed within two (2) inch of the first label and marked "FROM".
- C.
The first label is placed within 12 inches of the connector and marked "TO", and the second is placed within one (1) inch of the first label and marked "FROM".
- D.
The first label is placed within 12 inches of the connector and marked "TO", and the second is placed within two (2) inch of the first label and marked "FROM".
Correct Answer
D. The first label is placed within 12 inches of the connector and marked "TO", and the second is placed within two (2) inch of the first label and marked "FROM".Explanation
The correct answer is that the first label is placed within 12 inches of the connector and marked "TO", and the second is placed within two (2) inches of the first label and marked "FROM". This labeling system helps to identify the direction of the cable, indicating where it is going (TO) and where it is coming from (FROM). Placing the labels within a specific distance of each other ensures that they are easily visible and can be read together to determine the cable's direction.Rate this question:
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- 15.
Why should the number of splices be controlled during fiber optic installation?
- A.
Minimize transmission loss.
- B.
To aid in trouble shooting.
- C.
Reduce potential damage.
- D.
Prevent eavesdropping.
Correct Answer
A. Minimize transmission loss.Explanation
Controlling the number of splices during fiber optic installation is important to minimize transmission loss. Each splice point in a fiber optic cable introduces a certain amount of signal loss, so by minimizing the number of splices, the overall transmission loss can be reduced. This is crucial for maintaining the quality and integrity of the transmitted data.Rate this question:
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- 16.
Which type of label will have machine printed markings of indelible ink?
- A.
Adhesive
- B.
Special foil
- C.
Cable sheath
- D.
Heat shrink tubing
Correct Answer
A. AdhesiveExplanation
Adhesive labels are the type of labels that can have machine-printed markings of indelible ink. Adhesive labels are commonly used for labeling various items and surfaces, and the machine-printed markings ensure clear and permanent identification. The indelible ink used on adhesive labels is resistant to fading, smudging, and other forms of damage, making it ideal for long-lasting labeling purposes.Rate this question:
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- 17.
Who determines of local checklists and/or work cards are required for equipment?
- A.
Supervisor
- B.
Job control
- C.
Commander
- D.
Flight commander/chief
Correct Answer
D. Flight commander/chiefExplanation
The flight commander/chief is responsible for determining if local checklists and/or work cards are required for equipment. They have the authority and knowledge to assess the specific needs and requirements of the equipment and ensure that appropriate checklists and work cards are in place for efficient and safe operations.Rate this question:
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- 18.
What are the three main functions of grounding?
- A.
Personnel safety, equipment protection, and noise reduction.
- B.
Signal amplification, personnel safety, and emissions security.
- C.
Equipment protection, signal amplification, and capacitance reaction.
- D.
Corrosion prevention, emissions security, and over-voltage protection.
Correct Answer
A. Personnel safety, equipment protection, and noise reduction.Explanation
The three main functions of grounding are personnel safety, equipment protection, and noise reduction. Grounding helps to prevent electrical shocks to individuals by providing a path for electric current to flow safely into the ground. It also protects equipment by providing a reference point for electrical circuits and preventing damage from electrical faults. Additionally, grounding helps to reduce noise interference in electrical systems, improving the quality of signals and preventing disruptions.Rate this question:
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- 19.
The facility ground system to uses surge arrestors is the
- A.
Earth electrode
- B.
Fault protection
- C.
Signal reference
- D.
Lightning protection
Correct Answer
D. Lightning protectionExplanation
The facility ground system uses surge arrestors for lightning protection. Surge arrestors are devices that divert excess electrical energy caused by lightning strikes away from sensitive equipment and into the ground. This helps to prevent damage to the equipment and ensures the safety of the facility and its occupants. By installing surge arrestors, the facility's ground system can effectively protect against the potentially destructive effects of lightning strikes.Rate this question:
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- 20.
What is the establishment of a low-impedance path between two metal surfaces?
- A.
Bonding
- B.
Shielding
- C.
Annealing
- D.
Grounding
Correct Answer
A. BondingExplanation
Bonding refers to the process of creating a low-impedance path between two metal surfaces. This is done to ensure a strong and reliable connection between the surfaces, allowing for the efficient transfer of electrical current or signals. By bonding the surfaces together, any potential resistance or impedance is minimized, reducing the risk of signal loss or interference. This is commonly used in various industries, such as electronics and telecommunications, to maintain proper grounding and ensure optimal performance and safety.Rate this question:
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- 21.
The RED designation is used for equipment processing
- A.
Unencrypted unclassified information.
- B.
Clear-text unclassified information.
- C.
Encrypted classified information.
- D.
Clear-text classified information.
Correct Answer
D. Clear-text classified information.Explanation
The RED designation is used for equipment processing clear-text classified information. This means that the equipment is authorized to handle unencrypted, unclassified information that is considered sensitive and classified. This information can be accessed and processed without any encryption or additional security measures, but it is still classified and requires proper handling and protection.Rate this question:
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- 22.
Which electronic discharge sensitive (ESD) class has a sensitivity range from 0 - 999 volts?
- A.
Class I
- B.
Class II
- C.
Class III
- D.
Class IV
Correct Answer
A. Class IExplanation
Class I electronic discharge sensitive (ESD) devices have a sensitivity range from 0 - 999 volts. This means that they are able to detect and be affected by electrostatic discharges within this voltage range. Class II, Class III, and Class IV may have different sensitivity ranges, but the question specifically asks for the class that covers 0 - 999 volts, which is Class I.Rate this question:
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- 23.
Which of these activities would generate the most electrostatic voltage?
- A.
Working at a bench
- B.
Walking across carpet
- C.
Walking across a vinyl floor
- D.
Picking up a common plastic bag
Correct Answer
B. Walking across carpetExplanation
Walking across carpet generates the most electrostatic voltage because when we walk on a carpet, friction is created between our shoes and the carpet fibers. This friction causes the transfer of electrons from the carpet to our shoes, resulting in an accumulation of static electricity. As a result, walking across carpet can generate a significant amount of electrostatic voltage.Rate this question:
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- 24.
Which distinct region of the electromagnetic pulse is produced by the interactions between the ewapon products and the earth's atmosphere?
- A.
Secondary
- B.
Radiated
- C.
Plasma
- D.
Source
Correct Answer
D. SourceExplanation
The correct answer is "Source." The question is asking about the distinct region of the electromagnetic pulse that is produced by the interactions between the weapon products and the earth's atmosphere. The term "source" refers to the origin or starting point of something. In this context, it suggests that the electromagnetic pulse is generated at the source of the weapon products' interaction with the atmosphere.Rate this question:
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- 25.
What source region electromagnetic pulse region has a primarily vertical electromagnetic pulse electric field and what structures are affected?
- A.
Radiated; antennas and bore site feedhorns.
- B.
Plasma; antennas and bore site feedhorns.
- C.
Secondary; cables and ground wires.
- D.
Source; cables and ground wires.
Correct Answer
A. Radiated; antennas and bore site feedhorns.Explanation
The correct answer is Radiated; antennas and bore site feedhorns. When a radiated electromagnetic pulse occurs, it generates a primarily vertical electric field. This type of pulse affects antennas and bore site feedhorns, which are structures used for transmitting and receiving electromagnetic signals. The vertical electric field can induce high voltages and currents in these structures, potentially causing damage or disruption to their operation.Rate this question:
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- 26.
Which of the following statements is true concerning shielding?
- A.
Cables should be of unshielded construction.
- B.
Only ventilation ports are shielded along the walls.
- C.
Sensitive equipment will be located within the shielded barrier.
- D.
All power lines supplying shielded areas do not require filters.
Correct Answer
C. Sensitive equipment will be located within the shielded barrier.Explanation
The statement "Sensitive equipment will be located within the shielded barrier" is true concerning shielding. Shielding is used to protect sensitive equipment from electromagnetic interference (EMI) or radio frequency interference (RFI). By locating sensitive equipment within a shielded barrier, it can be protected from external electromagnetic disturbances that could potentially disrupt its operation. This ensures that the equipment functions properly without any interference from external sources.Rate this question:
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- 27.
Little or no variations in the strength of the interfering signal when moving the receiving antenna for short distance normally indicates
- A.
Enemy jamming
- B.
Internal interference
- C.
Radio receiver trouble
- D.
Unintentional interference
Correct Answer
A. Enemy jammingExplanation
Little or no variations in the strength of the interfering signal when moving the receiving antenna for a short distance normally indicates enemy jamming. This means that the interfering signal remains constant regardless of the movement of the antenna. Enemy jamming refers to deliberate attempts by an adversary to disrupt or interfere with communication systems. In this case, the lack of variation in the interfering signal suggests that it is intentionally being maintained at a consistent level, indicating the presence of enemy jamming.Rate this question:
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- 28.
What type of equipment often generates many spurious emissions?
- A.
Slow tuning receiver
- B.
Rapid tuning receiver
- C.
Slow tuning transmitter
- D.
Rapid tuning transmitter
Correct Answer
D. Rapid tuning transmitterExplanation
A rapid tuning transmitter often generates many spurious emissions. This is because rapid tuning transmitters are designed to quickly change frequencies, which can result in unintended emissions outside of the desired frequency range. These spurious emissions can cause interference with other equipment and can be a problem in radio communication systems.Rate this question:
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- 29.
What man-made noise results from voltage surges, arcing, or corona discharges?
- A.
Relays
- B.
Lighting
- C.
Power line
- D.
Switching equipment
Correct Answer
C. Power lineExplanation
Power lines can generate man-made noise due to voltage surges, arcing, or corona discharges. These phenomena can cause disturbances in the electrical current flowing through the power lines, resulting in audible noise. This noise can interfere with communication systems and cause disruptions in nearby electronic devices. Therefore, power lines are the correct answer as they are known to produce noise in such situations.Rate this question:
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- 30.
Who is tasked to provide interference resolution support to the unified commanders?
- A.
The operator
- B.
Joint Spectrum Center
- C.
Installation spectrum manager
- D.
Federal Communications Commission
Correct Answer
B. Joint Spectrum CenterExplanation
The Joint Spectrum Center is tasked with providing interference resolution support to the unified commanders. They are responsible for managing and coordinating the use of the electromagnetic spectrum by military forces. This includes identifying and resolving any interference issues that may arise during military operations. The Joint Spectrum Center plays a crucial role in ensuring effective and efficient communication and coordination among military units.Rate this question:
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- 31.
Who is the focal point for emission security (EMSEC) matters at an installation?
- A.
Information security officer (IAO)
- B.
Wing information assurance office (WIAO)
- C.
Information security program manager (ISPM)
- D.
Communications and information system officer (CSO)
Correct Answer
B. Wing information assurance office (WIAO)Explanation
The Wing Information Assurance Office (WIAO) is the focal point for emission security (EMSEC) matters at an installation. They are responsible for ensuring that all communication and information systems are secure and protected from any potential threats or vulnerabilities. The WIAO works closely with other personnel, such as the Information Security Officer (IAO) and the Information Security Program Manager (ISPM), to implement and enforce EMSEC policies and procedures. The Communications and Information System Officer (CSO) may also play a role in EMSEC matters, but the WIAO is specifically designated as the focal point for these issues.Rate this question:
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- 32.
What plays a major role in a conductor's ability to minimizing compromising emanations?
- A.
Distance and angles
- B.
Distance and separation
- C.
Induction and grounding
- D.
Induction and impedance
Correct Answer
A. Distance and anglesExplanation
Distance and angles play a major role in a conductor's ability to minimize compromising emanations. By increasing the distance between the conductor and potential sources of interference, the conductor can reduce the likelihood of electromagnetic interference. Additionally, adjusting the angles at which the conductor is positioned can help to minimize the impact of electromagnetic fields. By considering both distance and angles, conductors can effectively minimize compromising emanations.Rate this question:
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- 33.
What secondary cell is prone to memory effect?
- A.
Nickel cadmium
- B.
Carbon zinc
- C.
Lead-acid
- D.
Lithium
Correct Answer
A. Nickel cadmiumExplanation
Nickel cadmium is prone to memory effect. Memory effect is a phenomenon in which the battery "remembers" its shallow discharge cycles and loses capacity over time. This occurs when the battery is repeatedly charged before it is fully discharged, causing the battery to remember the reduced capacity and not utilize its full potential. Nickel cadmium batteries are particularly susceptible to this effect, requiring them to be fully discharged before recharging to avoid capacity loss.Rate this question:
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- 34.
What power line fault category is symptomatic of a short term decrease in voltage levels?
- A.
Sag
- B.
Spike
- C.
Noise
- D.
Blackout
Correct Answer
A. SagExplanation
A sag is a power line fault category that is symptomatic of a short-term decrease in voltage levels. It occurs when there is a temporary drop in voltage, usually caused by a fault in the power line or a sudden increase in demand. This can lead to a decrease in the performance of electrical equipment connected to the power line, as they may not receive enough power to operate properly. A sag is different from a blackout, which is a complete loss of power, and spikes and noise, which involve sudden increases or disturbances in voltage levels.Rate this question:
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- 35.
What power line fault category is symptomatic of a total loss of utility power?
- A.
Sag
- B.
Spike
- C.
Noise
- D.
Blackout
Correct Answer
D. BlackoutExplanation
A blackout is a complete loss of utility power, meaning that there is no electricity available. During a blackout, all electrical devices and systems relying on utility power will cease to function. This is different from other power line faults such as sag, spike, or noise, which may cause fluctuations or disturbances in power supply but do not result in a total loss of utility power.Rate this question:
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- 36.
What power line fault category is more typically referred to as electromagnetic interference (EMI) and radio frequency interference (RFI)?
- A.
Sag
- B.
Spike
- C.
Noise
- D.
Blackout
Correct Answer
C. NoiseExplanation
Electromagnetic interference (EMI) and radio frequency interference (RFI) are commonly associated with the power line fault category known as "Noise." Noise refers to any unwanted electrical signal that can disrupt the normal operation of electronic devices. EMI and RFI are types of noise that can be caused by electromagnetic radiation from various sources, such as power lines, radio transmitters, or electronic equipment. They can interfere with the proper functioning of sensitive electronic devices, leading to signal degradation, data corruption, or even equipment failure.Rate this question:
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- 37.
What type of uninterruptible power supply (UPS) has traditionally been referred to as "offline" by technicians?
- A.
Passive standby
- B.
Line interactive
- C.
Double conversion
- D.
Ferro resonant standby
Correct Answer
A. Passive standbyExplanation
A passive standby UPS is traditionally referred to as "offline" by technicians. This type of UPS operates by allowing the connected devices to run on utility power directly, without any power conditioning or battery backup. In the event of a power outage or disturbance, the UPS quickly switches to battery power, providing backup power to the connected devices. The term "offline" is used because the UPS is not actively regulating or conditioning the power supply, but rather stands by passively until needed.Rate this question:
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- 38.
What type of uninterruptible power supply uses a transformer or inductor between the utility power source and the load to correct or filter some variations in input power?
- A.
Passive standby
- B.
Line interactive
- C.
Double conversion
- D.
Ferro resonant standby
Correct Answer
B. Line interactiveExplanation
A line interactive uninterruptible power supply (UPS) uses a transformer or inductor between the utility power source and the load to correct or filter some variations in input power. This type of UPS is able to regulate the voltage and filter out power disturbances, such as voltage sags or surges, without having to switch to battery power. It provides a more stable and reliable power supply to the load, making it a suitable choice for protecting sensitive equipment from power fluctuations.Rate this question:
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- 39.
How many phases of generator power are usually required for industrial and commercial applications?
- A.
Single
- B.
Double
- C.
Three
- D.
Four
Correct Answer
C. ThreeExplanation
In industrial and commercial applications, three phases of generator power are usually required. This is because three-phase power provides a more balanced and efficient distribution of electrical power compared to single or double phases. It allows for higher power transmission, reduces voltage drop, and enables the use of three-phase motors that are commonly used in industrial machinery. Therefore, three phases of generator power are preferred in order to meet the power demands of industrial and commercial settings effectively.Rate this question:
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- 40.
What are the three general categories used to produce modulation in radio frequency (RF) transmission today?
- A.
Binary amplitude shift keying, frequency shift keying, and phase shift keying..
- B.
Pulse amplitude, pulse width, and pulse position.
- C.
Amplitude, frequency, and phase.
- D.
Analog, digital, and shift keying.
Correct Answer
C. Amplitude, frequency, and pHase.Explanation
The three general categories used to produce modulation in radio frequency (RF) transmission today are amplitude, frequency, and phase. Modulation is the process of varying one or more properties of a carrier signal in order to transmit information. In amplitude modulation (AM), the amplitude of the carrier signal is varied to encode the information. In frequency modulation (FM), the frequency of the carrier signal is varied. In phase modulation (PM), the phase of the carrier signal is varied. These three categories are widely used in RF transmission to encode and transmit data efficiently and effectively.Rate this question:
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- 41.
When the modulating signal and carrier signal are combined within a modulator, the output signal contains
- A.
Modulating signal, upper sideband, lower sideband
- B.
Carrier, upper sideband, lower sideband
- C.
Upper sideband and lower sideband
- D.
Carrier and modulating signal
Correct Answer
B. Carrier, upper sideband, lower sidebandExplanation
When the modulating signal and carrier signal are combined within a modulator, the resulting output signal contains the carrier signal, as well as the upper sideband and lower sideband. This is because the modulator combines the modulating signal with the carrier signal to create new frequencies that are the sum and difference of the original frequencies. The carrier signal represents the original frequency, while the upper and lower sidebands represent the frequencies that are higher and lower than the carrier frequency.Rate this question:
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- 42.
What factor determines the spacing of the sidebands in an amplitude modulated signal?
- A.
Amplitude of the modulating signal
- B.
Frequency of the modulating signal
- C.
Amplitude of the carrier signal
- D.
Frequency of the carrier signal
Correct Answer
B. Frequency of the modulating signalExplanation
The spacing of the sidebands in an amplitude modulated signal is determined by the frequency of the modulating signal. In amplitude modulation, the modulating signal alters the amplitude of the carrier signal, resulting in the creation of sidebands. The frequency of the modulating signal directly affects the spacing between these sidebands. A higher frequency modulating signal will result in sidebands that are closer together, while a lower frequency modulating signal will result in sidebands that are further apart.Rate this question:
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- 43.
The amount of effect or change that the intelligence has on the carrier in an amplitude modulated signal is expressed as the
- A.
Percent of modulation
- B.
Modulation index
- C.
Bandwidth
- D.
Deviation
Correct Answer
A. Percent of modulationExplanation
The amount of effect or change that the intelligence has on the carrier in an amplitude modulated signal is expressed as the percent of modulation. This refers to the percentage of variation in the carrier signal caused by the modulating signal. It is a measure of how much the carrier signal is modified or modulated by the intelligence signal. The higher the percent of modulation, the greater the variation in the carrier signal, and thus the more information or intelligence is conveyed.Rate this question:
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- 44.
Reducing modulation to less than 100 percent gives
- A.
More total power
- B.
A reduction in carrier power
- C.
No reduction in carrier power
- D.
A reduction in carrier and sideband power
Correct Answer
C. No reduction in carrier powerExplanation
When modulation is reduced to less than 100 percent, it means that the amplitude of the carrier signal is not completely modulated by the information signal. In this case, the carrier power remains unchanged because the modulation is not affecting the amplitude of the carrier signal. The reduction in modulation only affects the sideband power, which is the power carried by the modulated signal around the carrier frequency. Therefore, there is no reduction in carrier power.Rate this question:
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- 45.
The output of the oscillator in a frequency modulation (FM) modulation increases in frequency with each
- A.
Positive half cycle of the carrier
- B.
Negative half cycle of the carrier
- C.
Positive half cycle of the modulating signal
- D.
Negative half cycle of the modulating signal
Correct Answer
C. Positive half cycle of the modulating signalExplanation
In frequency modulation (FM), the output of the oscillator increases in frequency with each positive half cycle of the modulating signal. This means that as the amplitude of the modulating signal increases during the positive half cycle, the frequency of the carrier signal also increases. This results in a modulation of the carrier signal's frequency, which is the basic principle of FM modulation.Rate this question:
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- 46.
A 5 kilohertz (kHz) modulating signal has enough peak voltage to cause a deviation of 15 kHz. What is the modulation index?
- A.
5
- B.
3
- C.
0.5
- D.
0.3
Correct Answer
B. 3Explanation
The modulation index is a measure of how much a carrier signal is modulated by a modulating signal. In this case, the modulating signal has a frequency of 5 kHz and is causing a deviation of 15 kHz. The modulation index can be calculated by dividing the deviation by the modulating frequency, which gives a value of 3. This means that the carrier signal is modulated 3 times its original frequency by the modulating signal.Rate this question:
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- 47.
What is the narrow frequency band between adjacent stations used to prevent frequency modulated sidebands from overlapping?
- A.
Space
- B.
Guard band
- C.
Buffer zone
- D.
Prevention field
Correct Answer
B. Guard bandExplanation
A guard band is a narrow frequency band that is placed between adjacent stations to prevent frequency modulated sidebands from overlapping. This ensures that there is no interference or signal distortion between the neighboring stations. The guard band acts as a buffer zone, providing a separation between the frequencies used by different stations, thus maintaining the integrity and quality of the transmitted signals.Rate this question:
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- 48.
What is the advantage of adding more phase shifts?
- A.
Easier detection
- B.
Smaller bit error rate
- C.
Better signal-to-noise ratio
- D.
Higher data rates within a given bandwidth
Correct Answer
B. Smaller bit error rateExplanation
Adding more phase shifts can result in a smaller bit error rate. This is because with more phase shifts, the signal becomes more robust against noise and interference. Each phase shift represents a different symbol, and by increasing the number of possible symbols, the system can better distinguish between them and reduce the likelihood of errors. This can lead to a more reliable and accurate transmission of data, resulting in a smaller bit error rate.Rate this question:
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- 49.
What is the first step in the pulse code modulation process?
- A.
Discrete amplitudes are assigned to the sampling pulses.
- B.
A binary code number is assigned to the sample.
- C.
The quantizer limits the amplitude of the pulses.
- D.
The analog signal is band limited.
Correct Answer
D. The analog signal is band limited.Explanation
The first step in the pulse code modulation process is to band limit the analog signal. This means that the signal is filtered to remove any frequencies outside a certain range. This is done to ensure that the signal can be accurately represented and sampled without any distortion or loss of information. Band limiting helps to prevent aliasing and ensures that the digital representation of the signal is as close to the original analog signal as possible.Rate this question:
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- 50.
Quantization in the pulse code modulation process is
- A.
Converting a continuous time signal into a discrete time signal.
- B.
Ensuring the input to the sampler never exceeds maximum frequency.
- C.
Placing an infinite number of amplitude values to a finite number of values.
- D.
Limiting the highest and lowest frequency encoded before it goes to the sampler.
Correct Answer
C. Placing an infinite number of amplitude values to a finite number of values.Explanation
Quantization in pulse code modulation (PCM) is the process of converting a continuous time signal into a discrete time signal by placing an infinite number of amplitude values to a finite number of values. In PCM, the continuous analog signal is sampled and then each sample is quantized by assigning it to the nearest available discrete value. This allows for the representation of the continuous signal using a finite number of discrete values, which can be easily encoded and transmitted.Rate this question:
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Mar 21, 2023Quiz Edited by
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Jul 20, 2020Quiz Created by
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