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

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	Only General Class or higher amateur licenses
C	An unrestricted Radiotelephone Operator Permit
D	Any amateur license with an FCC Marine or Aircraft endorsement

3. - E1B08

What limitations may the FCC place on an amateur station if its signal causes interference to domestic broadcast reception, assuming that the receivers involved are of good engineering design?

Select	Answer
A	The amateur station must cease operation on all frequencies below 30 MHz
B	The amateur station must avoid transmitting during certain hours on frequencies that cause the interference
C	The amateur station must cease operation on all frequencies above 30 MHz
D	The amateur station must cease operation

4. - E1C12

On what portion of the 630 meter band are phone emissions permitted?

Select	Answer
A	The entire band
B	Only the bottom 3 kHz
C	None
D	Only the top 3 kHz

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?

Select	Answer
A	All these choices are correct
B	A photocopy of the station license
C	A label with the name, address, and telephone number of the control operator
D	A label with the name, address, and telephone number of the station licensee

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 FCC
C	The VE session manager
D	The VEC coordinating the session

7. - E1F01

On what frequencies are spread spectrum transmissions permitted?

Select	Answer
A	Only on amateur frequencies above 144 MHz
B	Only on amateur frequencies above 420 MHz
C	Only on amateur frequencies above 50 MHz
D	Only on amateur frequencies above 222 MHz

8. - E2A10

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

Select	Answer
A	Geostationary
B	Geomagnetic
C	HEO
D	LEO

9. - E2B04

How is color information sent in analog SSTV?

Select	Answer
A	Color is sent in a color burst at the end of each line
B	Color is amplitude modulated on the frequency modulated intensity signal
C	Color lines are sent sequentially
D	Color information is sent on a 2.8 kHz subcarrier

10. - E2C12

What technique do individual nodes use to form a mesh network?

Select	Answer
A	Forward error correction and Viterbi codes
B	Discovery and link establishment protocols
C	Custom code plugs for the local trunking systems
D	Acting as store-and-forward digipeaters

11. - E2D07

What digital protocol is used by APRS?

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

12. - E2E08

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

Select	Answer
A	Hellschreiber
B	PACTOR
C	AMTOR
D	RTTY

13. - E3A11

What is a typical range for tropospheric propagation of microwave signals?

Select	Answer
A	100 miles to 300 miles
B	10 miles to 50 miles
C	1200 miles
D	2500 miles

14. - E3B03

What is the best time of day for transequatorial propagation?

Select	Answer
A	Noon
B	Afternoon or early evening
C	Morning
D	Late at night

15. - E3C13

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

Select	Answer
A	Elliptical
B	Circular
C	Vertical
D	Horizontal

16. - E4A03

Which of the following test instruments is used to display spurious signals and/or intermodulation distortion products generated by an SSB transmitter?

Select	Answer
A	A time-domain reflectometer
B	A spectrum analyzer
C	A wattmeter
D	A logic analyzer

17. - E4B04

Which S parameter represents input port return loss or reflection coefficient (equivalent to VSWR)?

Select	Answer
A	S22
B	S11
C	S21
D	S12

18. - E4C02

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

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

19. - E4D02

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

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

20. - E4E04

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

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

21. - E5A13

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

Select	Answer
A	Fewer components are needed for the same performance
B	Phase shift can become uncontrolled
C	Internal voltages increase
D	Parasitic effects are minimized

22. - E5B02

What letter is commonly used to represent susceptance?

Select	Answer
A	B
B	Y
C	G
D	X

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 6
B	Point 5
C	Point 2
D	Point 4

24. - E5D02

Why is it important to keep lead lengths short for components used in circuits for VHF and above?

Select	Answer
A	To avoid unwanted inductive reactance
B	All these choices are correct
C	To maintain component lifetime
D	To increase the thermal time constant

25. - E6A07

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

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

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. - E6C02

What happens when the level of a comparator's input signal crosses the threshold?

Select	Answer
A	The IC input can be damaged
B	The feedback loop becomes unstable
C	The comparator changes its output state
D	The comparator enters latch-up

28. - E6D12

What is inductor saturation?

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

29. - E6E07

What type of transmission line is used for connections to MMICs?

Select	Answer
A	Parallel wire
B	Microstrip
C	Miniature coax
D	Circular waveguide

30. - E6F11

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

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

31. - E7A03

Which of the following can divide the frequency of a pulse train by 2?

Select	Answer
A	An XOR gate
B	A multiplexer
C	An OR gate
D	A flip-flop

32. - E7B17

Why are odd-order rather than even-order intermodulation distortion products of concern in linear power amplifiers?

Select	Answer
A	Because they are relatively close in frequency to the desired signal
B	Because they are relatively far in frequency from the desired signal
C	Because they maintain the sidebands, thus causing multiple duplicate signals
D	Because they invert the sidebands causing distortion

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 amplitude of the signals passing through the filter
C	The relative frequencies of the individual crystals
D	The gain of the RF stage preceding the filter

34. - E7D02

What is a characteristic of a switching electronic voltage regulator?

Select	Answer
A	The resistance of a control element is varied in direct proportion to the line voltage or load current
B	It gives a ramp voltage at its output
C	The controlled device's duty cycle is changed to produce a constant average output voltage
D	It is generally less efficient than a linear regulator

35. - E7E04

What is one way a single-sideband phone signal can be generated?

Select	Answer
A	By driving a product detector with a DSB signal
B	By using a loop modulator followed by a mixer
C	By using a balanced modulator followed by a filter
D	By using a reactance modulator followed by a mixer

36. - E7F05

How frequently must an analog signal be sampled by an analog-to-digital converter so that the signal can be accurately reproduced?

Select	Answer
A	At the same rate as the highest frequency component of the signal
B	At four times the rate of the highest frequency component of the signal
C	At least twice the rate of the highest frequency component of the signal
D	At least half the rate of the highest frequency component of the signal

37. - E7G08

How does the gain of an ideal operational amplifier vary with frequency?

Select	Answer
A	It decreases linearly with increasing frequency
B	It decreases logarithmically with increasing frequency
C	It does not vary with frequency
D	It increases linearly with increasing frequency

38. - E7H01

What are three oscillator circuits used in amateur radio equipment?

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

39. - E8A11

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

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

40. - E8B09

What is deviation ratio?

Select	Answer
A	The ratio of the audio modulating frequency to the center carrier frequency
B	The ratio of the carrier center frequency to the audio modulating frequency
C	The ratio of the highest audio modulating frequency to the average audio modulating frequency
D	The ratio of the maximum carrier frequency deviation to the highest audio modulating frequency

41. - E8C01

How is Forward Error Correction implemented?

Select	Answer
A	By the receiving station repeating each block of three data characters
B	By transmitting a special algorithm to the receiving station along with the data characters
C	By transmitting extra data that may be used to detect and correct transmission errors
D	By varying the frequency shift of the transmitted signal according to a predefined algorithm

42. - E8D09

What is considered an acceptable maximum IMD level for an idling PSK signal?

Select	Answer
A	-20 dB
B	+10 dB
C	+15 dB
D	-30 dB

43. - E9A08

What is antenna bandwidth?

Select	Answer
A	Antenna length divided by the number of elements
B	The frequency range over which an antenna satisfies a performance requirement
C	The angle formed between two imaginary lines drawn through the element ends
D	The angle between the half-power radiation points

44. - E9B10

What is the principle of a Method of Moments analysis?

Select	Answer
A	A wire is modeled as a single sine-wave current generator
B	A wire is modeled as a single sine-wave voltage source
C	A wire is modeled as a series of segments, each having a uniform value of current
D	A wire is modeled as a series of segments, each having a distinct value of voltage across it

45. - E9C14

How does the performance of a horizontally polarized antenna mounted on the side of a hill compare with the same antenna mounted on flat ground?

Select	Answer
A	The horizontal beamwidth decreases in the downhill direction
B	The main lobe takeoff angle decreases in the downhill direction
C	The horizontal beamwidth increases in the uphill direction
D	The main lobe takeoff angle increases in the downhill direction

46. - E9D06

What happens to the SWR bandwidth when one or more loading coils are used to resonate an electrically short antenna?

Select	Answer
A	It is increased
B	It is unchanged if the loading coil is located at the feed point
C	It is unchanged if the loading coil is located at a voltage maximum point
D	It is decreased

47. - E9E08

What is a use for a Wilkinson divider?

Select	Answer
A	It is used to feed low-impedance loads from a high-impedance source
B	It divides the operating frequency of a transmitter signal so it can be used on a lower frequency band
C	It is used to feed high-impedance antennas from a low-impedance source
D	It is used to divide power equally between two 50-ohm loads while maintaining 50-ohm input impedance

48. - E9F03

Why is the physical length of a coaxial cable transmission line shorter than its electrical length?

Select	Answer
A	Electrical signals move more slowly in a coaxial cable than in air
B	The surge impedance is higher in a parallel feed line
C	Skin effect is less pronounced in the coaxial cable
D	The characteristic impedance is higher in a parallel feed line

49. - E9G02

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

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

50. - E9H08

What is the function of a sense antenna?

Select	Answer
A	It allows DF antennas to receive signals at different vertical angles
B	It increases the sensitivity of a DF antenna array
C	It provides diversity reception that cancels multipath signals
D	It modifies the pattern of a DF antenna array to provide a null in one direction

Figure E5-1