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Volume 1 UREs - Randomized Questions & Answers
- 1.What is an example of analog-to-digital and didgital-to-analog techniques?
- A.
Amplitude modulation (AM) and frequency modulation (FM)
- B.
Pulse code modulation (PCM) and frequency shift keying (FSK)
- C.
Phase modulation (PM) and quadrature phase shift keying (QPSK)
- D.
Pulse code modulation (PCM) and continuously variable slope delta (CVSD) modulation
- 2.What converts analog signal information into an analog carrier signal?
- A.
Delta modulation (DM)
- B.
Digital modulation
- C.
Analog modulation
- D.
Adaptive modulation
- 3.What converts analog signal information into a digital carrier signal?
- A.
Delta modulation (DM)
- B.
Analog modulation
- C.
Digital modulation
- D.
Adaptive modulation
- 4.The information-carrying components that occur on either side of a carrier are called
- A.
Sidebands
- B.
Sine waves
- C.
Frequency translators
- D.
Modulating frequencies
- 5.Amplitude modulation (AM) requires a bandwidth that is
- A.
Twice that of the modulating signal
- B.
Half that of the modulating signal
- C.
Twice that of the carrier signal
- D.
Half that of the carrier signal
- 6.The upper sideband in a signal-sideband supppressed carrier (SSBSC) modulating is eliminated by
- A.
Filtering
- B.
Detection
- C.
Compression
- D.
Companding
- 7.We can express the 6-to-1 improvement of the single-sideband suppressed carrier (SSBSC) modulation over conventional amplitude modulation (AM) as
- A.
2 decibels (dB) of improvement
- B.
4 dB of improvement
- C.
6 dB of improvement
- D.
8 dB of improvement
- 8.The only basic waveform in nature is a
- A.
Carrier wave
- B.
Pure sine wave
- C.
Resultant wave
- D.
Composite wave
- 9.A modulated waveform that contains a carrier plus two sidebands for each modulation frequency is a description of
- A.
A phase modulation (PM)
- B.
A pulse modulation
- C.
A frequency modulation (FM)
- D.
An amplitude modulation (AM)
- 10.If 100 percent modulation is exceeded and there is distortion in the modulating signal, additional sidebands are generated. We identify these sidebands as what?
- A.
Transmitted intelelligence
- B.
Intensity of speech
- C.
Composite waves
- D.
Splatter
- 11.The amount of deviation in a frequency modulation (FM) signal is directly proportional to the modulating signal's
- A.
Phase
- B.
Amplitude
- C.
Frequency
- D.
Amplitude and frequency
- 12.The amount of phase shift in a phase modulation (PM) signal is directly proportional to the
- A.
Modulation index
- B.
Rate of phase shift
- C.
Frequency of the modulating signal
- D.
Amplitude of the modulating signal
- 13.What form of modulation is insensitive to signal variations?
- A.
Delta
- B.
Frequency shift keying (FSK)
- C.
Pulse-amplitude modulation (PAM)
- D.
Binary-phase shift keying or bi-phase shift keying (BPSK)
- 14.In quadrature-phase shift keying (QPSK) the radio frequency (RF) bandwidth for a quadriphase signal is what of that required by a bi-phase signal, given the same data rate.
- A.
Four times
- B.
Double
- C.
Half
- D.
The same
- 15.What is the main advantage of differential phase shift keying (DPSK)?
- A.
Carrier presence is required to detect changes
- B.
It requires a less complex receiver than a basic phase shift keying(PSK) signal
- C.
It requires a more complex receiver than a basic PSK signal
- D.
The demodulator needs to detect changes in absolute phase values
- 16.Which of the following is not considered an analog modulation tehniques?
- A.
Pulse-amplitude modulation (PAM)
- B.
Pulse-duration modulation (PDM)
- C.
Pulse-position modulation (PPM)
- D.
Pulse-code modulation (PCM)
- 17.The form of pulse modulation in which the pulse is varied within a set range of positions is known as
- A.
Pulse-amplitude modulation (PAM)
- B.
Pulse-duration modulation (PDM)
- C.
Pulse-position modulation (PPM)
- D.
Pulse-code modulation (PCM)
- 18.Quantized analog modulation is actually
- A.
Pulse-amplitude modulation (PAM)
- B.
Pulse-duration modulation (PDM)
- C.
Less tolerant of noise than frequency modulation (FM)
- D.
Analog-to-digital conversion
- 19.How many bits per character of a 16-step pulse-code modulation (PCM) system are used to describe the quantized analog sample?
- A.
3
- B.
4
- C.
5
- D.
8
- 20.The process of coding pulse code modulation (PCM) quantized pulses to make them a constant duration and amplitude is
- A.
Encoding
- B.
Companding
- C.
Uniform quantizing
- D.
Nonuniform quantizing
- 21.In Time Division Multiplexing (TDM), the transmitting multiplexer will put a bit or a byte from each of the incoming lines into a specifically allocated what?
- A.
Channel
- B.
Trunk
- C.
Time slot
- D.
Port
- 22.The two major types of frame structures are
- A.
Low speed and high speed
- B.
High speed and EBCDIC
- C.
CCITT and low speed
- D.
EBCDIC and CCITT
- 23.The method of multiplexing the T1 multiplexer uses is
- A.
Frequency division
- B.
Binary division
- C.
Pulse division
- D.
Time division
- 24.Wave-division multiplexing (WDM) creates the virutal channels for multiplexing them together for transmission by using different
- A.
Wavelengths or lambdas
- B.
Wavelengths or gammas
- C.
Frequencies or lambdas
- D.
Frequencies or gammas
- 25.The most common wave-division multiplexing (WDM) system uses how many wavelengths?
- A.
One wavelength
- B.
Two wavelengths
- C.
Three wavelengths
- D.
Four wavelengths
- 26.Individual pulses within a digital signal are
- A.
Bits
- B.
Bytes
- C.
Codes
- D.
Blocks
- 27.What unit is most commonly used in data systems to express signaling speed?
- A.
Baud
- B.
Baudot
- C.
Sense interface
- D.
Bits per second
- 28.Bit count integrity problems are primarily caused by
- A.
Impedance mismatch
- B.
System timing faults
- C.
Improper equipment settings
- D.
Changes in atmospheric conditions
- 29.Three catagories of synchronization used in digital data circuits are
- A.
Synchronous, asynchronous, and isochronous
- B.
Isochronous, asynchronous, and bisynchronous
- C.
Nonsynchronous, bisynchronous, and synchronous
- D.
Asynchronous, bisynchronous, and nonsynchronous
- 30.Which option is a characteristic of synchronous data operation?
- A.
Timing pulses are transmitted within the signal stream
- B.
Start and stop pulses control data transmission
- C.
System timing is not of critical importance
- D.
All data bits are the same length in time
- 31.A digital signal that contains sychronizing bits within the signal stream describes
- A.
Synchronous operation
- B.
Asynchronous operation
- C.
Synchronous and/or isochronous operation
- D.
Asynchronous and/or synchronous operation
- 32.In what type of signal is the information contained in the transition, and there is a transition from one state to the other only when a mark bit is sent?
- A.
Non-return-to-zero (NRZ) level
- B.
Non-return-to-zero mark
- C.
Non-return-to-zero space
- D.
Return-to-zero level
- 33.In what type of signal does the signal level move to one of the discrete signal levels, but returns to the zero level after a predetermined time?
- A.
Non-return-to-zero (NRZ) level
- B.
Non-return-to-zero mark
- C.
Non-return-to-zero space
- D.
Return-to-zero
- 34.Which statement best describes an alternate mark inversion (AMI) signal?
- A.
The information is transmitted in three different voltage levels
- B.
A logic one is transmitted as positive voltage if the previous logic one was negative
- C.
The level always returns to zero for 50 percent of the bit cycle after every transition
- D.
Bipolar violations are intentionally inserted into a data signal to break up long strings of zeros
- 35.Digital coding techniques such as binary with eight-zero substitution (B8ZS) are becoming more popular because they are designed to
- A.
Provide error-free signaling
- B.
Operate at higher data rates
- C.
Eliminate bipolar violations
- D.
Maintain ones density standards
- 36.Which statement best describes a binary with eight-zero substitution (B8ZS) signal?
- A.
The information is transmitted in three different voltage levels
- B.
A logic one is transmitted as positive voltage if the previous logic one was negative
- C.
The level always returns to zero for 50 percent of the bit cycle after every transition
- D.
Bipolar violations are intentionally inserted into a data signal to break up long strings of zeros
- 37.The major difference between conditioned di-phase (CDI) and other schemes is the
- A.
Lack of mid-bit transitions
- B.
Use of mid-bit transitions for timing
- C.
Data being encoded in the mid-bit transitions
- D.
Voltage levels used for signaling the mid-bid transitions
- 38.How many bits are in the D4 framing sequence?
- A.
8
- B.
12
- C.
24
- D.
48
- 39.How many bits are in the extended superframe format (ESF) framing sequence?
- A.
8
- B.
12
- C.
24
- D.
48
- 40.What communications control signal uses a two-frequency dialing combination?
- A.
Pulse dialing
- B.
Tone dialing
- C.
Digit dialing
- D.
Address dialing
- 41.What communications information signal uses a continuous 350- and 440-Hz frequency pair?
- A.
Dial tone
- B.
Ringback signal
- C.
Off-hook alert
- D.
Call waiting
- 42.What communications information signal uses a signal cycled on and off for 0.5 second and contains the generation of a 480- and 620-Hz frequency pair?
- A.
Dial tone
- B.
Busy signal
- C.
Off-hook alert
- D.
Call waiting
- 43.What communications supervisory signal uses a continuous application of direct current voltage for signaling?
- A.
Record warning
- B.
Fast busy signal
- C.
Loop-start
- D.
E and M
- 44.When is the voltage applied in loop-start signaling?
- A.
When dial tone is present
- B.
On-hook condition
- C.
Off-hook condition
- D.
During the ringback signal
- 45.In common associated signaling (CAS), what is the seventh bit in frames 6 and 12 used to convey signaling information known as?
- A.
Bit robbing
- B.
Bit stuffing
- C.
Frame correction
- D.
Frame enhancement
- 46.In what common channel signaling (CCS) mode are the messages relating to signaling between two points conveyed directly interconnecting these signaling points?
- A.
Associated mode
- B.
Nonassociated mode
- C.
Quasi-associated mode
- D.
Multi-associated mode
- 47.What are the two principle weighting characteristics in use with telecommunication circuit noise?
- A.
Institute of Electronic and Electrical Engineers and CCITT psophometric
- B.
Noise analysis and CCITT psophometric
- C.
CCITT psophometric and C-message
- D.
C-message and noise analysis
- 48.While timing makes sure the equipment is sending and receiving bits at the same time intervals, synchronization makes sure that the
- A.
Receive equipment timing is set properly
- B.
Transmit equipment timing is set properly
- C.
Receive equipment can find its own place in the bit stream
- D.
Transmit equipment can find its place in the bit stream
- 49.What term is associated with the delay or lag introduced in the application of voltage from one section to the next?
- A.
Latency
- B.
Phase delay
- C.
Propagation constant
- D.
Phase delay distortion
- 50.Attenuation distortion is caused by
- A.
A line loss for various frequency components comprising a voice transmission
- B.
The line loss, the distance of transmission lines, and faults in the transmission cables
- C.
Faults in the transmission cables and the number of splices in the line varying with the frequency
- D.
Differing attenuation rates for the various frequency components comprising a voice frequency transmission
- 51.Jamming a portion of the frequency spectrum is an example of
- A.
Electronic combat
- B.
Electronic protection
- C.
Electronic attack
- D.
Electronic warfare support
- 52.The definition of electronic attack can be found in which publication?
- A.
Air Force Doctrine Document 2-5.1
- B.
Air Force Instruction 10-101
- C.
Air Force Policy Memorandum 2-1
- D.
Air Force Manual 2-5.1
- 53.Any actions we take to protect our forces, facilities, and equipment for electronic action that can destroy or degrade our capabilities is considered
- A.
Electronic combat
- B.
Electronic protection
- C.
Electronic attack
- D.
Electronic warfare support
- 54.Varying the pulse repetition frequency on a radar set is an example of
- A.
Electronic combat
- B.
Electronic attack
- C.
Electronic protection
- D.
Electronic warfare support
- 55.Electronic warfare support includes devices such as
- A.
Anti-radiation missles and directed energy weapons
- B.
Intelligence platforms and noise jamming systems
- C.
Radar warning receivers and intelligence systems
- D.
Directed energy weapons and radar warning receivers
- 56.When a multimeter has three input terminal jacks, which jack is always used?
- A.
Voltage terminal
- B.
Common terminal
- C.
Voltage and current terminal
- D.
Common and current terminal
- 57.When using a multimeter, which mode should be used if the reading is unreadable due to fluctuations?
- A.
Range
- B.
Frequency
- C.
Display hold
- D.
Minimum/maximum (MIN/MAX)
- 58.When using a multimeter, which mode should be used if the reading fluctuates and a more accurate reading is desired?
- A.
Minimum/maximum (MIN/MAX)
- B.
Display hold
- C.
Frequency
- D.
Range
- 59.When using an ohmmeter to take a resistance reading, what preliminary precaution should you take?
- A.
Properly seat the test lead into the current input terminal jack
- B.
Disconnect the power from the circuit being tested
- C.
Place the meter in the frequency mode
- D.
Set the range for maximum reading
- 60.What principle of operation does the time domain reflectometer use to test cables?
- A.
Amplitude
- B.
Frequency
- C.
Audio
- D.
Radar
- 61.Which push-buttons would you select to get 125-ohm (Ω) impedance on the time domain refelctometer?
- A.
50Ω, 75Ω, and 125Ω
- B.
75Ω and 125Ω
- C.
50Ω and 125Ω
- D.
50Ω and 75Ω
- 62.What is the power that is reflected back to an optical source in the time domain refelctometer (TDR)?
- A.
Reflection
- B.
Backscatter
- C.
Scatter coefficient
- D.
Refelction coefficient
- 63.What are the two major sections of a bit error rate test (BERT) set?
- A.
Emitter and detector
- B.
Emitter and receiver
- C.
Transmitter and detector generator
- D.
Transmitter and receiver
- 64.Which section of a bit error rate test (BERT) set measueres the received test pattern?
- A.
Transmitter
- B.
Emitter
- C.
Detector
- D.
Receiver
- 65.What type of framing format should you use to conduct a bit error rate test (BERT) on a T1 circuit configured for binary with eight-zero substitution (B8ZS) coding?
- A.
Extended superframe
- B.
Alternate mark inversion
- C.
Return-to-zero
- D.
Superframe
- 66.When performing a bit error rate test (BERT), what dertermines the size of a test pattern segment?
- A.
The total number of bits in the test pattern
- B.
The total number of bytes that represent the bit test pattern
- C.
The number of bits that can represent the total number of bits in the test pattern
- D.
The number of bits in the number of bytes that are equally divided into the test pattern
- 67.What type of error is the result of two successive logic one pulses of the same polarity in violation of alternate mark inversion coding rules?
- A.
Cyclic redundancy check
- B.
Bipolar violation
- C.
Bit slip
- D.
Frame
- 68.On a breakout box, how many RS-232 key interface signals can be monitored and accessed individually?
- A.
12
- B.
20
- C.
24
- D.
25
- 69.The purpose of the miniature ON/OFF switches on a breakout box is to
- A.
Measure the individual interface signals
- B.
Change the voltage of individual interface signals
- C.
Allow the interruption of the individual interface condcutors
- D.
Allow the cross-patching of the individual interface conductors
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