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

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1. - E0A03

Over what range of frequencies are the FCC human body RF exposure limits most restrictive?

Select	Answer
A	300 to 3000 MHz
B	30 to 300 MHz
C	3 to 30 MHz
D	300 kHz to 3 MHz

2. - E1A12

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

Select	Answer
A	They are not permitted above 54 MHz
B	They are restricted to 7.245 MHz, 14.245 MHz, 21.345 MHz, and 28.945 MHz
C	None; they are allowed on all amateur frequencies
D	They are restricted to phone band segments

3. - E1B09

Which amateur stations may be operated under RACES rules?

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

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. - E1D07

Which HF amateur bands have frequencies authorized for space stations?

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

6. - E1E03

What is a Volunteer Examiner Coordinator?

Select	Answer
A	A person who has volunteered to administer amateur operator license examinations
B	A person who has volunteered to prepare amateur operator license examinations
C	An organization that has entered into an agreement with the FCC to coordinate, prepare, and administer amateur operator license examinations
D	The person who has entered into an agreement with the FCC to be 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	None, they must obtain a U.S. license
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	Full privileges, up to and including those of the Amateur Extra Class license, on the 80, 40, 20, 15, and 10 meter bands

8. - E2A10

What type of satellite appears to stay in one position in the sky?

Select	Answer
A	HEO
B	Geomagnetic
C	Geostationary
D	LEO

9. - E2B02

How many horizontal lines make up a fast-scan (NTSC) television frame?

Select	Answer
A	30
B	1080
C	525
D	60

10. - E2C04

Which of the following frequencies are sometimes used for amateur radio mesh networks?

Select	Answer
A	Cable TV channels 41 through 43
B	Frequencies shared with various unlicensed wireless data services
C	HF frequencies where digital communications are permitted
D	The 60 meter band channel centered on 5373 kHz

11. - E2D06

Which of the following describes a method of establishing EME contacts?

Select	Answer
A	High-speed CW identification to avoid fading
B	Storing and forwarding digital messages
C	Time synchronous transmissions alternately from each station
D	Judging optimum transmission times by monitoring beacons reflected from the moon

12. - E2E13

Which of these digital modes has the fastest data throughput under clear communication conditions?

Select	Answer
A	PSK31
B	170 Hz shift, 45 baud RTTY
C	300 baud packet
D	AMTOR

13. - E3A08

When a meteor strikes the Earth's atmosphere, a cylindrical region of free electrons is formed at what layer of the ionosphere?

Select	Answer
A	The F1 layer
B	The D layer
C	The E layer
D	The F2 layer

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 located on the magnetic equator
C	Propagation between a point on the equator and its antipodal point
D	Propagation between points at the same latitude

15. - E3C01

What does the radio communication term "ray tracing" describe?

Select	Answer
A	Determining the radiation pattern from an array of antennas
B	Modeling a radio wave's path through the ionosphere
C	The process in which an electronic display presents a pattern
D	Evaluating high voltage sources for x-rays

16. - E4A09

Which of the following is good practice when using an oscilloscope probe?

Select	Answer
A	Never use a high-impedance probe to measure a low-impedance circuit
B	All these choices are correct
C	Keep the signal ground connection of the probe as short as possible
D	Never use a DC-coupled probe to measure an AC circuit

17. - E4B05

What three test loads are used to calibrate an RF vector network analyzer?

Select	Answer
A	Short circuit, open circuit, and resonant circuit
B	50 ohms, 75 ohms, and 90 ohms
C	50 ohms through 1/8 wavelength, 1/4 wavelength, and 1/2 wavelength of coaxial cable
D	Short circuit, open circuit, and 50 ohms

18. - E4C02

Which of the following receiver circuits can be effective in eliminating interference from strong out-of-band signals?

Select	Answer
A	A front-end filter or pre-selector
B	A properly adjusted product detector
C	A notch filter
D	A narrow IF filter

19. - E4D06

What is the term for spurious signals generated by the combination of two or more signals in a non-linear device or circuit?

Select	Answer
A	Amplifier desensitization
B	Intermodulation
C	Neutralization
D	Adjacent channel interference

20. - E4E10

What might be the cause of a loud roaring or buzzing AC line interference that comes and goes at intervals?

Select	Answer
A	All these choices are correct
B	A malfunctioning illuminated advertising display
C	A defective doorbell or doorbell transformer inside a nearby residence
D	Arcing contacts in a thermostatically controlled device

21. - E5A03

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

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

22. - E5B01

What is the term for the time required for the capacitor in an RC circuit to be charged to 63.2% of the applied voltage or to discharge to 36.8% of its initial voltage?

Select	Answer
A	An exponential rate of one
B	A time factor of one
C	One exponential period
D	One time constant

23. - E5C09

When using rectangular coordinates to graph the impedance of a circuit, what do the axes represent?

Select	Answer
A	The X axis represents the resistive component and the Y axis represents the reactive component
B	The X axis represents the magnitude and the Y axis represents the phase angle
C	The X axis represents the phase angle and the Y axis represents the magnitude
D	The X axis represents the reactive component and the Y axis represents the resistive component

24. - E5D10

How can the true power be determined in an AC circuit where the voltage and current are out of phase?

Select	Answer
A	By dividing the reactive power by the power factor
B	By multiplying the reactive power by the power factor
C	By dividing the apparent power by the power factor
D	By multiplying the apparent power by the power factor

25. - E6A06

What is the beta of a bipolar junction transistor?

Select	Answer
A	The breakdown voltage of the base to collector junction
B	The frequency at which the current gain is reduced to 0.707
C	The change in collector current with respect to base current
D	The switching speed

26. - E6B07

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

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

27. - E6C08

In Figure E6-3, what is the schematic symbol for a NAND gate?

Select	Answer
A	2
B	3
C	1
D	4

28. - E6D12

What is inductor saturation?

Select	Answer
A	The ability of the inductor's core to store magnetic energy has been exceeded
B	Adjacent inductors become over-coupled
C	The inductor's voltage rating is exceeded causing a flashover
D	The inductor windings are over-coupled

29. - E6E01

Why is gallium arsenide (GaAs) useful for semiconductor devices operating at UHF and higher frequencies?

Select	Answer
A	Lower junction voltage drop
B	Higher noise figures
C	Lower transconductance
D	Higher electron mobility

30. - E6F06

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

Select	Answer
A	A heavy metal
B	A liquid semiconductor
C	A crystalline semiconductor
D	An ordinary metal

31. - E7A01

Which circuit is bistable?

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

32. - E7B05

What can be done to prevent unwanted oscillations in an RF power amplifier?

Select	Answer
A	Tune the stage for maximum SWR
B	Tune both the input and output for maximum power
C	Install parasitic suppressors and/or neutralize the stage
D	Use a phase inverter in the output filter

33. - E7C07

Which describes a Pi-L-network used for matching a vacuum tube final amplifier to a 50-ohm unbalanced output?

Select	Answer
A	A network with only three discrete parts
B	A Pi-network with an additional series inductor on the output
C	A Phase Inverter Load network
D	A matching network in which all components are isolated from ground

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. - E7E10

How does a diode envelope detector function?

Select	Answer
A	By rectification and filtering of RF signals
B	By sensing the change of reactance in the diode with respect to frequency
C	By breakdown of the Zener voltage
D	By mixing signals with noise in the transition region of the diode

36. - E7F01

What is meant by direct digital conversion as applied to software defined radios?

Select	Answer
A	Software is converted from source code to object code during operation of the receiver
B	A switching mixer is used to generate I and Q signals directly from the RF input
C	Incoming RF is converted to a control voltage for a voltage controlled oscillator
D	Incoming RF is digitized by an analog-to-digital converter without being mixed with a local oscillator signal

37. - E7G04

What is meant by the "op-amp input offset voltage"?

Select	Answer
A	The potential between the amplifier input terminals of the op-amp in an open loop condition
B	The difference between the output voltage of the op-amp and the input voltage required in the immediately following stage
C	The output voltage of the op-amp minus its input voltage
D	The differential input voltage needed to bring the open loop output voltage to zero

38. - E7H15

Which of these functions can be performed by a phase-locked loop?

Select	Answer
A	Frequency synthesis, FM demodulation
B	Photovoltaic conversion, optical coupling
C	Comparison of two digital input signals, digital pulse counter
D	Wide-band AF and RF power amplification

39. - E8A11

Which of the following is a measure of the quality of an analog-to-digital converter?

Select	Answer
A	Peak envelope power
B	Reciprocal mixing
C	Power factor
D	Total harmonic distortion

40. - E8B06

What is the deviation ratio of an FM-phone signal having a maximum frequency swing of plus or minus 7.5 kHz when the maximum modulation frequency is 3.5 kHz?

Select	Answer
A	0.214
B	2.14
C	0.47
D	47

41. - E8C08

How does ARQ accomplish error correction?

Select	Answer
A	If errors are detected, a retransmission is requested
B	If errors are detected, redundant data is substituted
C	Special polynomial codes provide automatic correction
D	Special binary codes provide automatic correction

42. - E8D01

Why are received spread spectrum signals resistant to interference?

Select	Answer
A	Signals not using the spread spectrum algorithm are suppressed in the receiver
B	The high power used by a spread spectrum transmitter keeps its signal from being easily overpowered
C	If interference is detected by the receiver it will signal the transmitter to change frequencies
D	The receiver is always equipped with a digital blanker

43. - E9A05

What is included in the total resistance of an antenna system?

Select	Answer
A	Radiation resistance plus transmission resistance
B	Radiation resistance plus space impedance
C	Radiation resistance plus loss resistance
D	Transmission-line resistance plus radiation resistance

44. - E9B04

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

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

45. - E9C05

Which of the following is a type of OCFD antenna?

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

46. - E9D04

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

Select	Answer
A	To swamp out harmonics
B	To minimize the Q
C	To minimize losses
D	To lower the radiation angle

47. - E9E10

Which of these choices is an effective way to match an antenna with a 100-ohm feed point impedance to a 50-ohm coaxial cable feed line?

Select	Answer
A	Connect a 1/4-wavelength open stub of 300-ohm twinlead in parallel with the coaxial feed line where it connects to the antenna
B	Insert a 1/2 wavelength piece of 300-ohm twinlead in series between the antenna terminals and the 50-ohm feed cable
C	Connect a 1/2 wavelength shorted stub of 75-ohm cable in parallel with the 50-ohm cable where it attaches to the antenna
D	Insert a 1/4-wavelength piece of 75-ohm coaxial cable transmission line in series between the antenna terminals and the 50-ohm feed cable

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	Infinite
C	An inductive reactance
D	A capacitive reactance

49. - E9G11

How are the wavelength scales on a Smith chart calibrated?

Select	Answer
A	In fractions of transmission line electrical frequency
B	In fractions of transmission line electrical wavelength
C	In fractions of antenna electrical wavelength
D	In fractions of antenna electrical frequency

50. - E9H11

What feature of a cardioid pattern antenna makes it useful for direction finding?

Select	Answer
A	A very sharp peak
B	A very sharp single null
C	High radiation angle
D	Broadband response

Figure E6-3

Figure E7-2