Anonymous User

Hamboozler

US Amateur Radio - Amateur Extra (Element 4, 2020-2024) Practice Test

Logging in (or registering) will help the system to select questions that you need to focus on.

1. - E0A08

What does SAR measure?

SelectAnswer
ASynthetic Aperture Ratio of the human body
BSignal Amplification Rating
CThe rate of RF energy reflected from stationary terrain
DThe rate at which RF energy is absorbed by the body

2. - E1A12

What special operating frequency restrictions are imposed on slow scan TV transmissions?

SelectAnswer
ANone; they are allowed on all amateur frequencies
BThey are restricted to 7.245 MHz, 14.245 MHz, 21.345 MHz, and 28.945 MHz
CThey are restricted to phone band segments
DThey are not permitted above 54 MHz

3. - E1B10

What frequencies are authorized to an amateur station operating under RACES rules?

SelectAnswer
AMilitary Auxiliary Radio System (MARS) channels
BSpecific segments in the amateur service MF, HF, VHF and UHF bands
CSpecific local government channels
DAll amateur service frequencies authorized to the control operator

4. - E1C07

At what level below a signal's mean power level is its bandwidth determined according to FCC rules?

SelectAnswer
A3 dB
B26 dB
C6 dB
D23 dB

5. - E1D05

What must be posted at the station location of a station being operated by telecommand on or within 50 km of the earth's surface?

SelectAnswer
AA photocopy of the station license
BA label with the name, address, and telephone number of the station licensee
CAll these choices are correct
DA label with the name, address, and telephone number of the control operator

6. - E1E08

To which of the following examinees may a VE not administer an examination?

SelectAnswer
ARelatives of the VE as listed in the FCC rules
BFriends of the VE
CAll these choices are correct
DEmployees of the VE

7. - E1F09

Which of the following conditions apply when transmitting spread spectrum emissions?

SelectAnswer
AThe transmitting station must be in an area regulated by the FCC or in a country that permits SS emissions
BThe transmission must not be used to obscure the meaning of any communication
CAll these choices are correct
DA station transmitting SS emission must not cause harmful interference to other stations employing other authorized emissions

8. - E2A04

What is meant by the term mode? as applied to an amateur radio satellite?

SelectAnswer
AThe satellite's orientation with respect to the Earth
BThe satellite's uplink and downlink frequency bands
CWhether the satellite is in a low earth or geostationary orbit
DWhether the satellite is in a polar or equatorial orbit

9. - E2B06

What is vestigial sideband modulation?

SelectAnswer
AA type of modulation in which one sideband is inverted
BAmplitude modulation in which one complete sideband and a portion of the other are transmitted
CNarrow-band FM modulation achieved by filtering one sideband from the audio before frequency modulating the carrier
DSpread spectrum modulation achieved by applying FM modulation following single sideband amplitude modulation

10. - E2C05

What is the function of a DX QSL Manager?

SelectAnswer
ATo handle the receiving and sending of confirmation cards for a DX station
BTo allocate frequencies for DXpeditions
CTo relay calls to and from a DX station
DTo run a net to allow many stations to contact a rare DX station

11. - E2D08

What type of packet frame is used to transmit APRS beacon data?

SelectAnswer
AUnnumbered Information
BConnect
CDisconnect
DAcknowledgement

12. - E2E05

Which of these digital modes does not support keyboard-to-keyboard operation?

SelectAnswer
ARTTY
BMFSK
CPSK31
DPACTOR

13. - E3A07

Atmospheric ducts capable of propagating microwave signals often form over what geographic feature?

SelectAnswer
AForests
BBodies of water
CUrban areas
DMountain ranges

14. - E3B04

What is meant by the terms "extraordinary" and "ordinary" waves?

SelectAnswer
ALong-path and short-path waves
BRefracted rays and reflected waves
CIndependent waves created in the ionosphere that are elliptically polarized
DExtraordinary waves describe rare long-skip propagation compared to ordinary waves, which travel shorter distances

15. - E3C05

What orientation of Bz (B sub z) increases the likelihood that incoming particles from the sun will cause disturbed conditions?

SelectAnswer
AWestward
BSouthward
CNorthward
DEastward

16. - E4A07

Which of the following is an advantage of using an antenna analyzer compared to an SWR bridge to measure antenna SWR?

SelectAnswer
AAntenna analyzers display a time-varying representation of the modulation envelope
BAntenna analyzers do not need an external RF source
CAntenna analyzers automatically tune your antenna for resonance
DAll these choices are correct

17. - E4B07

What do the subscripts of S parameters represent?

SelectAnswer
ARelative quality of the data
BThe relative time between measurements
CThe port or ports at which measurements are made
DFrequency order of the measurements

18. - E4C07

What does the MDS of a receiver represent?

SelectAnswer
AThe multiplex distortion stability
BThe maximum detectable spectrum
CThe meter display sensitivity
DThe minimum discernible signal

19. - E4D10

What does a third-order intercept level of 40 dBm mean with respect to receiver performance?

SelectAnswer
AA pair of 40 dBm input signals will theoretically generate a third-order intermodulation product that has the same output amplitude as either of the input signals
BThe receiver can tolerate signals up to 40 dB above the noise floor without producing third-order intermodulation products
CA pair of 1 mW input signals will produce a third-order intermodulation product that is 40 dB stronger than the input signal
DSignals less than 40 dBm will not generate audible third-order intermodulation products

20. - E4E03

Which of the following signals might a receiver noise blanker be able to remove from desired signals?

SelectAnswer
ASignals that appear at one IF but not another
BSignals that are constant at all IF levels
CSignals that have a sharply peaked frequency distribution
DSignals that appear across a wide bandwidth

21. - E5A13

What is an effect of increasing Q in a series resonant circuit?

SelectAnswer
AFewer components are needed for the same performance
BParasitic effects are minimized
CInternal voltages increase
DPhase shift can become uncontrolled

22. - E5B09

What is the relationship between the AC current through a capacitor and the voltage across a capacitor?

SelectAnswer
AVoltage and current are in phase
BCurrent leads voltage by 90 degrees
CVoltage and current are 180 degrees out of phase
DVoltage leads current by 90 degrees

23. - E5C02

How are impedances described in polar coordinates?

SelectAnswer
ABy X and R values
BBy real and imaginary parts
CBy Y and G values
DBy phase angle and magnitude

24. - E5D09

What happens to reactive power in an AC circuit that has both ideal inductors and ideal capacitors?

SelectAnswer
AIt is repeatedly exchanged between the associated magnetic and electric fields, but is not dissipated
BIt is dissipated as heat in the circuit
CIt is dissipated as kinetic energy in the circuit
DIt is dissipated in the formation of inductive and capacitive fields

25. - E6A08

What term indicates the frequency at which the grounded-base current gain of a transistor has decreased to 0.7 of the gain obtainable at 1 kHz?

SelectAnswer
AAlpha rejection frequency
BCorner frequency
CBeta cutoff frequency
DAlpha cutoff frequency

26. - E6B07

What is the failure mechanism when a junction diode fails due to excessive current?

SelectAnswer
AInsufficient forward voltage
BCharge carrier depletion
CExcessive junction temperature
DExcessive inverse voltage

27. - E6C03

What is tri-state logic?

SelectAnswer
ALogic devices that utilize ternary math
BLogic devices with 0, 1, and high-impedance output states
CLow-power logic devices designed to operate at 3 volts
DProprietary logic devices manufactured by Tri-State Devices

28. - E6D06

What core material property determines the inductance of an inductor?

SelectAnswer
APermeability
BThermal impedance
CReactivity
DResistance

29. - E6E05

Which of the following noise figure values is typical of a low-noise UHF preamplifier?

SelectAnswer
A-20 dBm
B44 dBm
C2 dB
D-10 dB

30. - E6F06

Which of these materials is most commonly used to create photoconductive devices?

SelectAnswer
AA heavy metal
BA crystalline semiconductor
CA liquid semiconductor
DAn ordinary metal

31. - E7A10

What is a truth table?

SelectAnswer
AA table of logic symbols that indicate the high logic states of an op-amp
BA diagram showing logic states when the digital device output is true
CA table of logic symbols that indicate the logic states of an op-amp
DA list of inputs and corresponding outputs for a digital device

32. - E7B03

Which of the following components form the output of a class D amplifier circuit?

SelectAnswer
AA temperature compensating load resistor to improve linearity
BA high-pass filter to compensate for low gain at low frequencies
CA low-pass filter to remove switching signal components
DA matched load resistor to prevent damage by switching transients

33. - E7C06

What are the distinguishing features of an elliptical filter?

SelectAnswer
AExtremely sharp cutoff with one or more notches in the stop band
BExtremely flat response over its pass band with gradually rounded stop band corners
CGradual passband rolloff with extreme stop band ripple
DGradual passband rolloff with minimal stop band ripple

34. - E7D08

What type of circuit is shown in Figure E7-2?

SelectAnswer
AGrounded emitter amplifier
BSwitching voltage regulator
CLinear voltage regulator
DMonostable multivibrator

35. - E7E01

Which of the following can be used to generate FM phone emissions?

SelectAnswer
AA balanced modulator on the audio amplifier
BA balanced modulator on the oscillator
CA reactance modulator on the final amplifier
DA reactance modulator on the oscillator

36. - E7F02

What kind of digital signal processing audio filter is used to remove unwanted noise from a received SSB signal?

SelectAnswer
AA phase-inverting filter
BA crystal-lattice filter
CA Hilbert-transform filter
DAn adaptive filter

37. - E7G01

What is the typical output impedance of an op-amp?

SelectAnswer
AVery high
B1000 ohms
C100 ohms
DVery low

38. - E7H01

What are three oscillator circuits used in amateur radio equipment?

SelectAnswer
ATaft, Hartley and Pierce
BTaft, Pierce and negative feedback
CPierce, Fenner and Beane
DColpitts, Hartley and Pierce

39. - E8A01

What is the name of the process that shows that a square wave is made up of a sine wave plus all its odd harmonics?

SelectAnswer
AVector analysis
BFourier analysis
CDifferential analysis
DNumerical analysis

40. - E8B11

What is digital time division multiplexing?

SelectAnswer
ATwo or more data streams are assigned to discrete sub-carriers on an FM transmitter
BTwo or more data streams share the same channel by transmitting time of transmission as the sub-carrier
CTwo or more signals are quadrature modulated to increase bandwidth efficiency
DTwo or more signals are arranged to share discrete time slots of a data transmission

41. - E8C01

How is Forward Error Correction implemented?

SelectAnswer
ABy transmitting a special algorithm to the receiving station along with the data characters
BBy the receiving station repeating each block of three data characters
CBy transmitting extra data that may be used to detect and correct transmission errors
DBy varying the frequency shift of the transmitted signal according to a predefined algorithm

42. - E8D01

Why are received spread spectrum signals resistant to interference?

SelectAnswer
AThe high power used by a spread spectrum transmitter keeps its signal from being easily overpowered
BSignals not using the spread spectrum algorithm are suppressed in the receiver
CIf interference is detected by the receiver it will signal the transmitter to change frequencies
DThe receiver is always equipped with a digital blanker

43. - E9A08

What is antenna bandwidth?

SelectAnswer
AAntenna length divided by the number of elements
BThe angle between the half-power radiation points
CThe frequency range over which an antenna satisfies a performance requirement
DThe angle formed between two imaginary lines drawn through the element ends

44. - E9B08

What is the far field of an antenna?

SelectAnswer
AThe region where radiated power dissipates over a specified time period
BThe region of the ionosphere where radiated power is not refracted
CThe region where the shape of the antenna pattern is independent of distance
DThe region where radiated field strengths are constant

45. - E9C11

How is the far-field elevation pattern of a vertically polarized antenna affected by being mounted over seawater versus soil?

SelectAnswer
AFewer vertical angle lobes will be present
BAdditional higher vertical angle lobes will appear
CThe low-angle radiation decreases
DThe low-angle radiation increases

46. - E9D04

Why should an HF mobile antenna loading coil have a high ratio of reactance to resistance?

SelectAnswer
ATo minimize the Q
BTo lower the radiation angle
CTo minimize losses
DTo swamp out harmonics

47. - E9E03

What is the name of the matching system that uses a section of transmission line connected in parallel with the feed line at or near the feed point?

SelectAnswer
AThe omega match
BThe stub match
CThe gamma match
DThe delta match

48. - E9F10

What impedance does a 1/8-wavelength transmission line present to a generator when the line is shorted at the far end?

SelectAnswer
AThe same as the characteristic impedance of the line
BAn inductive reactance
CZero
DA capacitive reactance

49. - E9G01

Which of the following can be calculated using a Smith chart?

SelectAnswer
AImpedance along transmission lines
BRadiation resistance
CAntenna radiation pattern
DRadio propagation

50. - E9H03

What is Receiving Directivity Factor (RDF)?

SelectAnswer
AForward gain compared to average gain over the entire hemisphere
BForward gain compared to the gain in the reverse direction
CRelative directivity compared to isotropic
DRelative directivity compared to a dipole

Figure E7-2