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. - E0A11

Which of the following injuries can result from using high-power UHF or microwave transmitters?

Select	Answer
A	Hearing loss caused by high voltage corona discharge
B	Localized heating of the body from RF exposure in excess of the MPE limits
C	Blood clotting from the intense magnetic field
D	Ingestion of ozone gas from the cooling system

2. - E1A11

Which of the following describes authorization or licensing required when operating an amateur station aboard a U.S.-registered vessel in international waters?

Select	Answer
A	Any FCC-issued amateur license
B	An unrestricted Radiotelephone Operator Permit
C	Only General Class or higher amateur licenses
D	Any amateur license with an FCC Marine or Aircraft endorsement

3. - E1B02

Which of the following is an acceptable bandwidth for Digital Radio Mondiale (DRM) based voice or SSTV digital transmissions made on the HF amateur bands?

Select	Answer
A	3 kHz
B	10 kHz
C	15 kHz
D	20 kHz

4. - E1C08

What is the maximum permissible duration of a remotely controlled station's transmissions if its control link malfunctions?

Select	Answer
A	5 minutes
B	10 minutes
C	30 seconds
D	3 minutes

5. - E1D07

Which HF amateur bands have frequencies authorized for space stations?

Select	Answer
A	Only the 40, 20, 17, 15, 12, and 10 meter bands
B	Only the 40, 20, 17, 15, and 10 meter bands
C	All HF bands
D	Only the 40, 30, 20, 15, 12, and 10 meter bands

6. - E1E11

What must the VE team do if an examinee scores a passing grade on all examination elements needed for an upgrade or new license?

Select	Answer
A	Three VEs must certify that the examinee is qualified for the license grant and that they have complied with the administering VE requirements
B	All these choices are correct
C	Photocopy all examination documents and forward them to the FCC for processing
D	Issue the examinee the new or upgrade license

7. - E1F10

Who may be the control operator of an auxiliary station?

Select	Answer
A	Only General, Advanced or Amateur Extra Class operators
B	Any licensed amateur operator
C	Only Technician, General, Advanced or Amateur Extra Class operators
D	Only Amateur Extra Class operators

8. - E2A08

Why should effective radiated power to a satellite that uses a linear transponder be limited?

Select	Answer
A	To avoid interfering with terrestrial QSOs
B	To avoid reducing the downlink power to all other users
C	To prevent the satellite from emitting out-of-band signals
D	To prevent creating errors in the satellite telemetry

9. - E2B12

What signals SSTV receiving software to begin a new picture line?

Select	Answer
A	A two-tone signal
B	Specific tone amplitudes
C	Elapsed time
D	Specific tone frequencies

10. - E2C07

What is the Cabrillo format?

Select	Answer
A	The most common set of contest rules
B	The rules of order for meetings between contest sponsors
C	A standard for submission of electronic contest logs
D	A method of exchanging information during a contest QSO

11. - E2D04

What technology is used to track, in real time, balloons carrying amateur radio transmitters?

Select	Answer
A	APRS
B	Bandwidth compressed LORAN
C	Doppler shift of beacon signals
D	Ultrasonics

12. - E2E08

Which of the following HF digital modes can be used to transfer binary files?

Select	Answer
A	PACTOR
B	Hellschreiber
C	AMTOR
D	RTTY

13. - E3A01

What is the approximate maximum separation measured along the surface of the Earth between two stations communicating by EME?

Select	Answer
A	2000 miles, if the moon is at apogee
B	12,000 miles, if the moon is visible by both stations
C	500 miles, if the moon is at perigee
D	5000 miles, if the moon is at perigee

14. - E3B01

What is transequatorial propagation?

Select	Answer
A	Propagation between two mid-latitude points at approximately the same distance north and south of the magnetic equator
B	Propagation between points at the same latitude
C	Propagation between points located on the magnetic equator
D	Propagation between a point on the equator and its antipodal point

15. - E3C10

What does the 304A solar parameter measure?

Select	Answer
A	The solar emission at 304 GHz, correlated to x-ray flare levels
B	The ratio of x-ray flux to radio flux, correlated to sunspot number
C	The solar wind velocity at 304 degrees from the solar equator, correlated to solar activity
D	UV emissions at 304 angstroms, correlated to the solar flux index

16. - E4A06

What is the effect of aliasing on a digital oscilloscope caused by setting the time base too slow?

Select	Answer
A	Excessive blanking occurs, which prevents display of the signal
B	All signals will have a DC offset
C	A false, jittery low-frequency version of the signal is displayed
D	Calibration of the vertical scale is no longer valid

17. - E4B07

What do the subscripts of S parameters represent?

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

18. - E4C04

What is the noise figure of a receiver?

Select	Answer
A	The ratio of atmospheric noise to phase noise
B	The ratio of the noise bandwidth in hertz to the theoretical bandwidth of a resistive network
C	The ratio of thermal noise to atmospheric noise
D	The ratio in dB of the noise generated by the receiver to the theoretical minimum noise

19. - E4D01

What is meant by the blocking dynamic range of a receiver?

Select	Answer
A	The minimum difference in dB between the levels of two FM signals that will cause one signal to block the other
B	The minimum difference in dB between two signals which produce third-order intermodulation products greater than the noise floor
C	The difference in dB between the noise floor and the level of an incoming signal that will cause 1 dB of gain compression
D	The difference in dB between the noise floor and the third-order intercept point

20. - E4E03

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

Select	Answer
A	Signals that appear at one IF but not another
B	Signals that are constant at all IF levels
C	Signals that have a sharply peaked frequency distribution
D	Signals that appear across a wide bandwidth

21. - E5A03

What is the magnitude of the impedance of a series RLC circuit at resonance?

Select	Answer
A	Approximately equal to capacitive reactance
B	Approximately equal to circuit resistance
C	Approximately equal to inductive reactance
D	High, as compared to the circuit resistance

22. - E5B03

How is impedance in polar form converted to an equivalent admittance?

Select	Answer
A	Square the magnitude and subtract 90 degrees from the angle
B	Take the square root of the magnitude and add 180 degrees to the angle
C	Take the reciprocal of the angle and change the sign of the magnitude
D	Take the reciprocal of the magnitude and change the sign of the angle

23. - E5C10

Which point on Figure E5-1 best represents the impedance of a series circuit consisting of a 400-ohm resistor and a 38-picofarad capacitor at 14 MHz?

Select	Answer
A	Point 5
B	Point 6
C	Point 2
D	Point 4

24. - E5D14

What is reactive power?

Select	Answer
A	Power lost because of capacitor leakage
B	Power consumed in wire resistance in an inductor
C	Wattless, nonproductive power
D	Power consumed in circuit Q

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

26. - E6B06

Which of the following is a common use of a Schottky diode?

Select	Answer
A	As a VHF/UHF mixer or detector
B	As a variable capacitance in an automatic frequency control circuit
C	As a constant voltage reference in a power supply
D	As a rectifier in high current power supplies

27. - E6C11

In Figure E6-3, what is the schematic symbol for the NOT operation (inverter)?

Select	Answer
A	4
B	6
C	2
D	5

28. - E6D10

What is a primary advantage of using a toroidal core instead of a solenoidal core in an inductor?

Select	Answer
A	Toroidal cores exhibit greater hysteresis
B	Toroidal cores make it easier to couple the magnetic energy into other components
C	Toroidal cores have lower Q characteristics
D	Toroidal cores confine most of the magnetic field within the core material

29. - E6E11

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

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

30. - E6F04

What is the photovoltaic effect?

Select	Answer
A	The conversion of voltage to current when exposed to light
B	The conversion of light to electrical energy
C	The conversion of electrical energy to mechanical energy
D	The tendency of a battery to discharge when exposed to light

31. - E7A05

Which of the following is a circuit that continuously alternates between two states without an external clock?

Select	Answer
A	Monostable multivibrator
B	T flip-flop
C	J-K flip-flop
D	Astable multivibrator

32. - E7B16

What is the effect of intermodulation products in a linear power amplifier?

Select	Answer
A	Low efficiency
B	Transmission of spurious signals
C	All these choices are correct
D	Creation of parasitic oscillations

33. - E7C01

How are the capacitors and inductors of a low-pass filter Pi-network arranged between the network's input and output?

Select	Answer
A	Two capacitors are in series between the input and output, and an inductor is connected between the two capacitors and ground
B	Two inductors are in series between the input and output, and a capacitor is connected between the two inductors and ground
C	An inductor is connected between the input and ground, another inductor is connected between the output and ground, and a capacitor is connected between the input and output
D	A capacitor is connected between the input and ground, another capacitor is connected between the output and ground, and an inductor is connected between input and output

34. - E7D04

Which of the following types of linear voltage regulator usually make the most efficient use of the primary power source?

Select	Answer
A	A series regulator
B	A shunt current source
C	A series current source
D	A shunt regulator

35. - E7E07

What is meant by the term "baseband" in radio communications?

Select	Answer
A	The basic oscillator frequency in an FM transmitter that is multiplied to increase the deviation and carrier frequency
B	The lowest frequency band that the transmitter or receiver covers
C	The unmodulated bandwidth of the transmitted signal
D	The frequency range occupied by a message signal prior to modulation

36. - E7F07

What function is performed by a Fast Fourier Transform?

Select	Answer
A	Converting 8-bit data to 16-bit data
B	Converting digital signals from the time domain to the frequency domain
C	Converting digital signals to analog form
D	Converting analog signals to digital form

37. - E7G07

What magnitude of voltage gain can be expected from the circuit in Figure E73 when R1 is 10 ohms and RF is 470 ohms?

Select	Answer
A	94
B	47
C	0.21
D	24

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

39. - E8A10

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

Select	Answer
A	All these choices are correct
B	Lower the input bandwidth to increase the effective resolution
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. - E8B11

What is digital time division multiplexing?

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

41. - E8C02

What is the definition of symbol rate in a digital transmission?

Select	Answer
A	The rate at which the waveform changes to convey information
B	The number of characters carried per second by the station-to-station link
C	The duration of each bit in a message sent over the air
D	The number of control characters in a message packet

42. - E8D07

What is a common cause of overmodulation of AFSK signals?

Select	Answer
A	Bit errors in the modem
B	Excessive transmit audio levels
C	Excessive numbers of retries
D	Ground loops

43. - E9A10

Which of the following improves the efficiency of a ground-mounted quarter-wave vertical antenna?

Select	Answer
A	Installing a radial system
B	All these choices are correct
C	Shortening the radiating element
D	Isolating the coax shield from ground

44. - E9B01

In the antenna radiation pattern shown in Figure E9-1, what is the beamwidth?

Select	Answer
A	30 degrees
B	25 degrees
C	75 degrees
D	50 degrees

45. - E9C01

What is the radiation pattern of two 1/4-wavelength vertical antennas spaced 1/2-wavelength apart and fed 180 degrees out of phase?

Select	Answer
A	A figure-8 oriented along the axis of the array
B	Cardioid
C	A figure-8 broadside to the axis of the array
D	Omni-directional

46. - E9D07

What is an advantage of using top loading in a shortened HF vertical antenna?

Select	Answer
A	Greater structural strength
B	Lower Q
C	Improved radiation efficiency
D	Higher losses

47. - E9E04

What is the purpose of the series capacitor in a gamma-type antenna matching network?

Select	Answer
A	To provide a rejection notch that prevents the radiation of harmonics
B	To transform the antenna impedance to a higher value
C	To cancel the inductive reactance of the matching network
D	To provide DC isolation between the feed line and the antenna

48. - E9F04

What impedance does a 1/2-wavelength transmission line present to a generator when the line is shorted at the far end?

Select	Answer
A	Very low impedance
B	The same as the output impedance of the generator
C	The same as the characteristic impedance of the line
D	Very high impedance

49. - E9G01

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

Select	Answer
A	Radio propagation
B	Radiation resistance
C	Impedance along transmission lines
D	Antenna radiation pattern

50. - E9H10

How can the output voltage of a multiple-turn receiving loop antenna be increased?

Select	Answer
A	By winding adjacent turns in opposing directions
B	By utilizing high impedance wire for the coupling loop
C	By reducing the permeability of the loop shield
D	By increasing the number of turns and/or the area

Figure E5-1

Figure E6-3

Figure E9-1