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

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1. - E0A05

What is one of the potential hazards of operating in the amateur radio microwave bands?

Select	Answer
A	The high gain antennas commonly used can result in high exposure levels
B	Microwaves often travel long distances by ionospheric reflection
C	Microwaves are ionizing radiation
D	The extremely high frequency energy can damage the joints of antenna structures

2. - E1A07

What is the maximum power permitted on the 2200 meter band?

Select	Answer
A	100 watts PEP
B	50 watts PEP
C	5 watts EIRP (Equivalent isotropic radiated power)
D	1 watt EIRP (Equivalent isotropic radiated power)

3. - E1B01

Which of the following constitutes a spurious emission?

Select	Answer
A	Any transmitted signal that unintentionally interferes with another licensed radio station
B	A signal transmitted to prevent its detection by any station other than the intended recipient
C	An amateur station transmission made without the proper call sign identification
D	An emission outside the signal's necessary bandwidth that can be reduced or eliminated without affecting the information transmitted

4. - E1C06

Which of the following is required in order to operate in accordance with CEPT rules in foreign countries where permitted?

Select	Answer
A	The U.S. embassy must approve of your operation
B	You must bring a copy of FCC Public Notice DA 16-1048
C	You must identify in the official language of the country in which you are operating
D	You must append "/CEPT" to your call sign

5. - E1D12

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

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

6. - E1E05

What is the minimum passing score on all amateur operator license examinations?

Select	Answer
A	Minimum passing score of 70%
B	Minimum passing score of 77%
C	Minimum passing score of 74%
D	Minimum passing score of 80%

7. - E1F04

Which of the following geographic descriptions approximately describes "Line A"?

Select	Answer
A	A line roughly parallel to and west of the U.S. Atlantic coastline
B	A line roughly parallel to and south of the border between the U.S. and Canada
C	A line roughly parallel to and east of the U.S. Pacific coastline
D	A line roughly parallel to and north of the border between the U.S. and Mexico

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. - E2B11

What is the function of the Vertical Interval Signaling (VIS) code sent as part of an SSTV transmission?

Select	Answer
A	To identify the SSTV mode being used
B	To provide vertical synchronization
C	To identify the call sign of the station transmitting
D	To lock the color burst oscillator in color SSTV images

10. - E2C05

What is the function of a DX QSL Manager?

Select	Answer
A	To handle the receiving and sending of confirmation cards for a DX station
B	To relay calls to and from a DX station
C	To run a net to allow many stations to contact a rare DX station
D	To allocate frequencies for DXpeditions

11. - E2D07

What digital protocol is used by APRS?

Select	Answer
A	AMTOR
B	AX.25
C	PACTOR
D	802.11

12. - E2E07

Which of the following is a possible reason that attempts to initiate contact with a digital station on a clear frequency are unsuccessful?

Select	Answer
A	Another station you are unable to hear is using the frequency
B	Your transmit frequency is incorrect
C	All these choices are correct
D	The protocol version you are using is not supported by the digital station

13. - E3A05

Tropospheric propagation of microwave signals often occurs in association with what phenomenon?

Select	Answer
A	Lightning discharges
B	Warm and cold fronts
C	Grayline
D	Sprites and jets

14. - E3B07

What happens to linearly polarized radio waves that split into ordinary and extraordinary waves in the ionosphere?

Select	Answer
A	They become elliptically polarized
B	They are bent toward the magnetic poles
C	They become phase locked
D	They become depolarized

15. - E3C13

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

Select	Answer
A	Elliptical
B	Horizontal
C	Vertical
D	Circular

16. - E4A07

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

Select	Answer
A	Antenna analyzers automatically tune your antenna for resonance
B	Antenna analyzers display a time-varying representation of the modulation envelope
C	Antenna analyzers do not need an external RF source
D	All these choices are correct

17. - E4B07

What do the subscripts of S parameters represent?

Select	Answer
A	The port or ports at which measurements are made
B	The relative time between measurements
C	Relative quality of the data
D	Frequency order of the measurements

18. - E4C01

What is an effect of excessive phase noise in a receiver's local oscillator?

Select	Answer
A	It decreases receiver third-order intercept point
B	It limits the receiver's ability to receive strong signals
C	It can combine with strong signals on nearby frequencies to generate interference
D	It can affect the receiver's frequency calibration

19. - E4D04

Which of the following may reduce or eliminate intermodulation interference in a repeater caused by another transmitter operating in close proximity?

Select	Answer
A	Utilizing a Class C final amplifier
B	Utilizing a Class D final amplifier
C	A band-pass filter in the feed line between the transmitter and receiver
D	A properly terminated circulator at the output of the repeater's transmitter

20. - E4E04

How can conducted and radiated noise caused by an automobile alternator be suppressed?

Select	Answer
A	By installing filter capacitors in series with the DC power lead and a blocking capacitor in the field lead
B	By installing a noise suppression resistor and a blocking capacitor in both leads
C	By installing a high-pass filter in series with the radio's power lead and a low-pass filter in parallel with the field lead
D	By connecting the radio's power leads directly to the battery and by installing coaxial capacitors in line with the alternator leads

21. - E5A07

What is the magnitude of the current at the input of a parallel RLC circuit at resonance?

Select	Answer
A	Minimum
B	R/L
C	L/R
D	Maximum

22. - E5B09

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

Select	Answer
A	Voltage and current are 180 degrees out of phase
B	Voltage leads current by 90 degrees
C	Current leads voltage by 90 degrees
D	Voltage and current are in phase

23. - E5C05

What is the name of the diagram used to show the phase relationship between impedances at a given frequency?

Select	Answer
A	Near field diagram
B	Venn diagram
C	Phasor diagram
D	Far field diagram

24. - E5D09

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

Select	Answer
A	It is repeatedly exchanged between the associated magnetic and electric fields, but is not dissipated
B	It is dissipated in the formation of inductive and capacitive fields
C	It is dissipated as heat in the circuit
D	It is dissipated as kinetic energy in the circuit

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?

Select	Answer
A	Alpha rejection frequency
B	Corner frequency
C	Alpha cutoff frequency
D	Beta cutoff frequency

26. - E6B02

What is an important characteristic of a Schottky diode as compared to an ordinary silicon diode when used as a power supply rectifier?

Select	Answer
A	Less forward voltage drop
B	Much higher reverse voltage breakdown
C	More constant reverse avalanche voltage
D	Longer carrier retention time

27. - E6C06

Why do CMOS digital integrated circuits have high immunity to noise on the input signal or power supply?

Select	Answer
A	Bandwidth is very limited
B	The input switching threshold is about one-half the power supply voltage
C	Large bypass capacitance is inherent
D	The input switching threshold is about two times the power supply voltage

28. - E6D11

Which type of core material decreases inductance when inserted into a coil?

Select	Answer
A	Powdered iron
B	Brass
C	Ceramic
D	Ferrite

29. - E6E10

What advantage does surface-mount technology offer at RF compared to using through-hole components?

Select	Answer
A	Shorter circuit-board traces
B	All these choices are correct
C	Components have less parasitic inductance and capacitance
D	Smaller circuit area

30. - E6F02

What happens to the conductivity of a photoconductive material when light shines on it?

Select	Answer
A	It decreases
B	It becomes unstable
C	It stays the same
D	It increases

31. - E7A04

How many flip-flops are required to divide a signal frequency by 4?

Select	Answer
A	8
B	4
C	1
D	2

32. - E7B06

Which of the following amplifier types reduces even-order harmonics?

Select	Answer
A	Class AB
B	Push-pull
C	Push-push
D	Class C

33. - E7C08

Which of the following factors has the greatest effect on the bandwidth and response shape of a crystal ladder filter?

Select	Answer
A	The DC voltage applied to the quartz crystal
B	The gain of the RF stage preceding the filter
C	The relative frequencies of the individual crystals
D	The amplitude of the signals passing through the filter

34. - E7D08

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

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

35. - E7E01

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

Select	Answer
A	A reactance modulator on the final amplifier
B	A balanced modulator on the oscillator
C	A balanced modulator on the audio amplifier
D	A reactance modulator on the oscillator

36. - E7F04

What is a common method of generating an SSB signal using digital signal processing?

Select	Answer
A	A frequency synthesizer removes the unwanted sidebands
B	Varying quartz crystal characteristics emulated in digital form
C	Mixing products are converted to voltages and subtracted by adder circuits
D	Signals are combined in quadrature phase relationship

37. - E7G01

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

Select	Answer
A	Very low
B	Very high
C	1000 ohms
D	100 ohms

38. - E7H01

What are three oscillator circuits used in amateur radio equipment?

Select	Answer
A	Taft, Pierce and negative feedback
B	Taft, Hartley and Pierce
C	Pierce, Fenner and Beane
D	Colpitts, Hartley and Pierce

39. - E8A10

What is the purpose of a low-pass filter used in conjunction with a digital-to-analog converter?

Select	Answer
A	Lower the input bandwidth to increase the effective resolution
B	All these choices are correct
C	Improve accuracy by removing out-of-sequence codes from the input
D	Remove harmonics from the output caused by the discrete analog levels generated

40. - E8B10

What is frequency division multiplexing?

Select	Answer
A	Two or more information streams are merged into a baseband, which then modulates the transmitter
B	The transmitted signal is divided into packets of information
C	Two or more information streams are merged into a digital combiner, which then pulse position modulates the transmitter
D	The transmitted signal jumps from band to band at a predetermined rate

41. - E8C10

How may data rate be increased without increasing bandwidth?

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

42. - E8D10

What are some of the differences between the Baudot digital code and ASCII?

Select	Answer
A	Baudot uses 5 data bits per character, ASCII uses 7 or 8; Baudot uses 2 characters as letters/figures shift codes, ASCII has no letters/figures shift code
B	Baudot uses 7 data bits per character, ASCII uses 8; Baudot has no letters/figures shift code, ASCII uses 2 letters/figures shift codes
C	Baudot uses 6 data bits per character, ASCII uses 7 or 8; Baudot has no letters/figures shift code, ASCII uses 2 letters/figures shift codes
D	Baudot uses 4 data bits per character, ASCII uses 7 or 8; Baudot uses 1 character as a letters/figures shift code, ASCII has no letters/figures code

43. - E9A02

What is the effective radiated power relative to a dipole of a repeater station with 150 watts transmitter power output, 2 dB feed line loss, 2.2 dB duplexer loss, and 7 dBd antenna gain?

Select	Answer
A	420 watts
B	286 watts
C	78.7 watts
D	1977 watts

44. - E9B06

What is the elevation angle of peak response in the antenna radiation pattern shown in Figure E9-2?

Select	Answer
A	7.5 degrees
B	25 degrees
C	75 degrees
D	45 degrees

45. - E9C09

Which of the following describes a G5RV antenna?

Select	Answer
A	A wide band dipole using shorted coaxial cable for the radiating elements and fed with a�4:1 balun
B	A multi-band dipole antenna fed with coax and a balun through a selected length of open wire transmission line
C	A phased array antenna consisting of multiple loops
D	A multi-band trap antenna

46. - E9D12

Which of the following would provide the best RF ground for your station?

Select	Answer
A	An electrically short connection to 3 or 4 interconnected ground rods via a series RF choke
B	An electrically short connection to a metal water pipe
C	A 50-ohm resistor connected to ground
D	An electrically short connection to 3 or 4 interconnected ground rods driven into the Earth

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 stub match
B	The gamma match
C	The delta match
D	The epsilon match

48. - E9F07

How does ladder line compare to small-diameter coaxial cable such as RG-58 at 50 MHz?

Select	Answer
A	Lower loss
B	Lower velocity factor
C	Smaller reflection coefficient
D	Higher SWR

49. - E9G02

What type of coordinate system is used in a Smith chart?

Select	Answer
A	Voltage circles and current arcs
B	Resistance circles and reactance arcs
C	Resistance lines and reactance chords
D	Voltage lines and current chords

50. - E9H03

What is Receiving Directivity Factor (RDF)?

Select	Answer
A	Relative directivity compared to isotropic
B	Forward gain compared to average gain over the entire hemisphere
C	Relative directivity compared to a dipole
D	Forward gain compared to the gain in the reverse direction

Figure E7-2

Figure E9-2