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

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1. - E0A01

What is the primary function of an external earth connection or ground rod?

Select	Answer
A	Reduce RFI to telephones and home entertainment systems
B	Reduce received noise
C	Lightning protection
D	Reduce RF current flow between pieces of equipment

2. - E1A08

If a station in a message forwarding system inadvertently forwards a message that is in violation of FCC rules, who is primarily accountable for the rules violation?

Select	Answer
A	The control operators of all the stations in the system
B	The control operators of all the stations in the system not authenticating the source from which they accept communications
C	The control operator of the originating station
D	The control operator of the packet bulletin board station

3. - E1B09

Which amateur stations may be operated under RACES rules?

Select	Answer
A	Any FCC-licensed amateur station certified by the responsible civil defense organization for the area served
B	Only those club stations licensed to Amateur Extra Class operators
C	Any FCC-licensed amateur station participating in the Military Auxiliary Radio System (MARS)
D	Any FCC-licensed amateur station except a Technician Class

4. - E1C01

What is the maximum bandwidth for a data emission on 60 meters?

Select	Answer
A	1.5 kHz
B	60 Hz
C	170 Hz
D	2.8 kHz

5. - E1D12

Which of the following amateur stations may transmit one-way communications?

Select	Answer
A	A message forwarding station or automatically controlled digital station
B	All these choices are correct
C	A local repeater or linked repeater station
D	A space station, beacon station, or telecommand station

6. - E1E06

Who is responsible for the proper conduct and necessary supervision during an amateur operator license examination session?

Select	Answer
A	Each administering VE
B	The VEC coordinating the session
C	The FCC
D	The VE session manager

7. - E1F02

What privileges are authorized in the U.S. to persons holding an amateur service license granted by the government of Canada?

Select	Answer
A	Full privileges, up to and including those of the Amateur Extra Class license, on the 80, 40, 20, 15, and 10 meter bands
B	All privileges of the Amateur Extra Class license
C	The operating terms and conditions of the Canadian amateur service license, not to exceed U.S. Amateur Extra Class license privileges
D	None, they must obtain a U.S. license

8. - E2A06

What are Keplerian elements?

Select	Answer
A	Phase reversing elements in a Yagi antenna
B	Encrypting codes used for spread spectrum modulation
C	Parameters that define the orbit of a satellite
D	High-emission heater filaments used in magnetron tubes

9. - E2B10

What aspect of an analog slow-scan television signal encodes the brightness of the picture?

Select	Answer
A	Tone amplitude
B	Tone frequency
C	Sync frequency
D	Sync amplitude

10. - E2C10

Why might a DX station state that they are listening on another frequency?

Select	Answer
A	Because the DX station may be transmitting on a frequency that is prohibited to some responding stations
B	To separate the calling stations from the DX station
C	To improve operating efficiency by reducing interference
D	All these choices are correct

11. - E2D05

What is one advantage of the JT65 mode?

Select	Answer
A	Uses only a 65 Hz bandwidth
B	The ability to decode signals which have a very low signal-to-noise ratio
C	Easily copied by ear if necessary
D	Permits fast-scan TV transmissions over narrow bandwidth

12. - E2E09

Which of the following HF digital modes uses variable-length coding for bandwidth efficiency?

Select	Answer
A	MT63
B	PACTOR
C	RTTY
D	PSK31

13. - E3A12

What is the cause of auroral activity?

Select	Answer
A	The interaction in the F2 layer between the solar wind and the Van Allen belt
B	Meteor showers concentrated in the extreme northern and southern latitudes
C	An extreme low-pressure area in the polar regions
D	The interaction in the E layer of charged particles from the Sun with the Earth's magnetic field

14. - E3B12

What is the primary characteristic of chordal hop propagation?

Select	Answer
A	Propagation away from the great circle bearing between stations
B	Successive ionospheric refractions without an intermediate reflection from the ground
C	Propagation across the geomagnetic equator
D	Signals reflected back toward the transmitting station

15. - E3C13

What type of polarization is best for ground-wave propagation?

Select	Answer
A	Circular
B	Elliptical
C	Vertical
D	Horizontal

16. - E4A10

Which of the following displays multiple digital signal states simultaneously?

Select	Answer
A	Modulation monitor
B	Network analyzer
C	Logic analyzer
D	Bit error rate tester

17. - E4B08

Which of the following can be used to measure the Q of a series-tuned circuit?

Select	Answer
A	The bandwidth of the circuit's frequency response
B	The inductance to capacitance ratio
C	The frequency shift
D	The resonant frequency of the circuit

18. - E4C15

What is reciprocal mixing?

Select	Answer
A	Two out-of-band signals mixing to generate an in-band spurious signal
B	Local oscillator phase noise mixing with adjacent strong signals to create interference to desired signals
C	Two digital signals combining from alternate time slots
D	In-phase signals cancelling in a mixer resulting in loss of receiver sensitivity

19. - E4D02

Which of the following describes problems caused by poor dynamic range in a receiver?

Select	Answer
A	Oscillator instability and severe audio distortion of all but the strongest received signals
B	Cross-modulation of the desired signal and insufficient audio power to operate the speaker
C	Spurious signals caused by cross-modulation and desensitization from strong adjacent signals
D	Oscillator instability requiring frequent retuning and loss of ability to recover the opposite sideband

20. - E4E08

What current flows equally on all conductors of an unshielded multi-conductor cable?

Select	Answer
A	Return current
B	Differential-mode current
C	Reactive current only
D	Common-mode current

21. - E5A10

How is the Q of an RLC series resonant circuit calculated?

Select	Answer
A	Reactance of either the inductance or capacitance divided by the resistance
B	Reactance of either the inductance or capacitance multiplied by the resistance
C	Resistance divided by the reactance of either the inductance or capacitance
D	Reactance of the inductance multiplied by the reactance of the capacitance

22. - E5B02

What letter is commonly used to represent susceptance?

Select	Answer
A	G
B	Y
C	B
D	X

23. - E5C06

What does the impedance 50-j25 represent?

Select	Answer
A	25 ohms resistance in series with 50 ohms capacitive reactance
B	50 ohms resistance in series with 25 ohms inductive reactance
C	25 ohms resistance in series with 50 ohms inductive reactance
D	50 ohms resistance in series with 25 ohms capacitive reactance

24. - E5D06

In what direction is the magnetic field oriented about a conductor in relation to the direction of electron flow?

Select	Answer
A	In a circle around the conductor
B	In the same direction as the current
C	In a direction opposite to the current
D	In all directions; omni-directional

25. - E6A07

Which of the following indicates that a silicon NPN junction transistor is biased on?

Select	Answer
A	Base-to-emitter voltage of approximately 6 to 7 volts
B	Base-to-emitter resistance of approximately 6 to 7 ohms
C	Base-to-emitter resistance of approximately 0.6 to 0.7 ohms
D	Base-to-emitter voltage of approximately 0.6 to 0.7 volts

26. - E6B07

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

Select	Answer
A	Insufficient forward voltage
B	Charge carrier depletion
C	Excessive junction temperature
D	Excessive inverse voltage

27. - E6C07

What best describes a pull-up or pull-down resistor?

Select	Answer
A	A resistor connected to an op-amp output that prevents signals from exceeding the power supply voltage
B	A resistor in a keying circuit used to reduce key clicks
C	A resistor connected to the positive or negative supply line used to establish a voltage when an input or output is an open circuit
D	A resistor that ensures that an oscillator frequency does not drift

28. - E6D13

What is the primary cause of inductor self-resonance?

Select	Answer
A	The skin effect
B	Non-linear core hysteresis
C	Inductive kickback
D	Inter-turn capacitance

29. - E6E11

What is a characteristic of DIP packaging used for integrated circuits?

Select	Answer
A	Package mounts in a direct inverted position
B	Two chips in each package (Dual In Package)
C	Low leakage doubly insulated package
D	A total of two rows of connecting pins placed on opposite sides of the package (Dual In-line Package)

30. - E6F11

What is the approximate open-circuit voltage produced by a fully illuminated silicon photovoltaic cell?

Select	Answer
A	0.5 V
B	0.1 V
C	1.5 V
D	12 V

31. - E7A01

Which circuit is bistable?

Select	Answer
A	An OR gate
B	A flip-flop
C	A bipolar amplifier
D	An AND gate

32. - E7B11

In Figure E7-1, what is the purpose of R3?

Select	Answer
A	Self bias
B	Output load resistor
C	Fixed bias
D	Emitter bypass

33. - E7C10

Which of the following filters would be the best choice for use in a 2 meter band repeater duplexer?

Select	Answer
A	An L-C filter
B	A DSP filter
C	A crystal filter
D	A cavity filter

34. - E7D08

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

Select	Answer
A	Switching voltage regulator
B	Linear voltage regulator
C	Grounded emitter amplifier
D	Monostable multivibrator

35. - E7E11

Which type of detector circuit is used for demodulating SSB signals?

Select	Answer
A	Phase comparator
B	Discriminator
C	Product detector
D	Phase detector

36. - E7F12

Which of the following is an advantage of a Finite Impulse Response (FIR) filter vs an Infinite Impulse Response (IIR) digital filter?

Select	Answer
A	All these choices are correct
B	FIR filters are easier to implement for a given set of passband rolloff requirements
C	FIR filters can delay all frequency components of the signal by the same amount
D	FIR filters can respond faster to impulses

37. - E7G12

What is an operational amplifier?

Select	Answer
A	An amplifier used to increase the average output of frequency modulated amateur signals to the legal limit
B	A RF amplifier used in the UHF and microwave regions
C	A high-gain, direct-coupled differential amplifier with very high input impedance and very low output impedance
D	A digital audio amplifier whose characteristics are determined by components external to the amplifier

38. - E7H13

Which of the following is a technique for providing highly accurate and stable oscillators needed for microwave transmission and reception?

Select	Answer
A	Use a GPS signal reference
B	Use a rubidium stabilized reference oscillator
C	All these choices are correct
D	Use a temperature-controlled high Q dielectric resonator

39. - E8A02

Which of the following is a type of analog-to-digital conversion?

Select	Answer
A	Level shifting
B	Successive approximation
C	Phase reversal
D	Harmonic regeneration

40. - E8B11

What is digital time division multiplexing?

Select	Answer
A	Two or more signals are arranged to share discrete time slots of a data transmission
B	Two or more data streams are assigned to discrete sub-carriers on an FM transmitter
C	Two or more signals are quadrature modulated to increase bandwidth efficiency
D	Two or more data streams share the same channel by transmitting time of transmission as the sub-carrier

41. - E8C10

How may data rate be increased without increasing bandwidth?

Select	Answer
A	It is impossible
B	Using forward error correction
C	Increasing analog-to-digital conversion resolution
D	Using a more efficient digital code

42. - E8D08

What parameter evaluates distortion of an AFSK signal caused by excessive input audio levels?

Select	Answer
A	Baud rate
B	Repeat Request Rate (RRR)
C	Signal-to-noise ratio
D	Intermodulation Distortion (IMD)

43. - E9A03

What is the radiation resistance of an antenna?

Select	Answer
A	The specific impedance of the antenna
B	The resistance in the atmosphere that an antenna must overcome to be able to radiate a signal
C	The value of a resistance that would dissipate the same amount of power as that radiated from an antenna
D	The combined losses of the antenna elements and feed line

44. - E9B04

What is the front-to-back ratio of the radiation pattern shown in Figure E92?

Select	Answer
A	38 dB
B	15 dB
C	28 dB
D	3 dB

45. - E9C05

Which of the following is a type of OCFD antenna?

Select	Answer
A	A folded dipole center-fed with 300-ohm transmission line
B	A dipole fed approximately 1/3 the way from one end with a 4:1 balun to provide multiband operation
C	A remotely tunable dipole antenna using orthogonally controlled frequency diversity
D	A multiband dipole antenna using one-way circular polarization for frequency diversity

46. - E9D08

What happens as the Q of an antenna increases?

Select	Answer
A	More common-mode current is present on the feed line
B	SWR bandwidth increases
C	SWR bandwidth decreases
D	Gain is reduced

47. - E9E02

What is the name of an antenna matching system that matches an unbalanced feed line to an antenna by feeding the driven element both at the center of the element and at a fraction of a wavelength to one side of center?

Select	Answer
A	The gamma match
B	The epsilon match
C	The stub match
D	The delta match

48. - E9F11

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

Select	Answer
A	The same as the characteristic impedance of the line
B	An inductive reactance
C	Infinite
D	A capacitive reactance

49. - E9G07

On the Smith chart shown in Figure E9-3, what is the only straight line shown?

Select	Answer
A	The current axis
B	The reactance axis
C	The voltage axis
D	The resistance axis

50. - E9H07

Why is RF attenuation used when direction-finding?

Select	Answer
A	To narrow the receiver bandwidth
B	To compensate for isotropic directivity and the antenna effect of feed lines
C	To increase receiver sensitivity
D	To prevent receiver overload which reduces pattern nulls

Figure E7-1

Figure E7-2

Figure E9-3