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

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1. - E0A04

When evaluating a site with multiple transmitters operating at the same time, the operators and licensees of which transmitters are responsible for mitigating over-exposure situations?

Select	Answer
A	Only commercial transmitters
B	Only the most powerful transmitter
C	Each transmitter operating with a duty cycle greater than 50 percent
D	Each transmitter that produces 5 percent or more of its MPE limit in areas where the total MPE limit is exceeded.

2. - E1A09

What action or actions should you take if your digital message forwarding station inadvertently forwards a communication that violates FCC rules?

Select	Answer
A	Notify the originating station that the communication does not comply with FCC rules
B	Notify the nearest FCC Field Engineers office
C	Discontinue forwarding the communication as soon as you become aware of it
D	All these choices are correct

3. - E1B12

What must the control operator of a repeater operating in the 70 cm band do if a radiolocation system experiences interference from that repeater?

Select	Answer
A	File an FAA NOTAM (Notice to Airmen) with the repeater system's ERP, call sign, and six-character grid locator
B	All these choices are correct
C	Reduce the repeater antenna HAAT (Height Above Average Terrain)
D	Cease operation or make changes to the repeater to mitigate the interference

4. - E1C03

How do the control operator responsibilities of a station under automatic control differ from one under local control?

Select	Answer
A	Under local control there is no control operator
B	Under automatic control there is no control operator
C	Under automatic control the control operator is not required to be present at the control point
D	Under local control a control operator is not required to be present at a control point

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

6. - E1E01

For which types of out-of-pocket expenses do the Part 97 rules state that VEs and VECs may be reimbursed?

Select	Answer
A	No expenses are authorized for reimbursement
B	Preparing, processing, administering, and coordinating an examination for an amateur radio operator license
C	Providing amateur operator license examination preparation training materials
D	Teaching an amateur operator license examination preparation course

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

8. - E2A12

What is the purpose of digital store-and-forward functions on an amateur radio satellite?

Select	Answer
A	To relay messages between satellites
B	To delay download of telemetry between satellites
C	To store digital messages in the satellite for later download by other stations
D	To upload operational software for the transponder

9. - E2B06

What is vestigial sideband modulation?

Select	Answer
A	A type of modulation in which one sideband is inverted
B	Amplitude modulation in which one complete sideband and a portion of the other are transmitted
C	Narrow-band FM modulation achieved by filtering one sideband from the audio before frequency modulating the carrier
D	Spread spectrum modulation achieved by applying FM modulation following single sideband amplitude modulation

10. - E2C08

Which of the following contacts may be confirmed through the U.S. QSL bureau system?

Select	Answer
A	Contacts using tactical call signs
B	Special event contacts between stations in the U.S.
C	Contacts between a U.S. station and a non-U.S. station
D	Repeater contacts between U.S. club members

11. - E2D10

How can an APRS station be used to help support a public service communications activity?

Select	Answer
A	An APRS station with a Global Positioning System unit can automatically transmit information to show a mobile station's position during the event
B	APRS stations with General Personnel Scanners can automatically relay the participant numbers and time as they pass the check points
C	An APRS station with an emergency medical technician can automatically transmit medical data to the nearest hospital
D	All these choices are correct

12. - E2E08

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

Select	Answer
A	AMTOR
B	Hellschreiber
C	RTTY
D	PACTOR

13. - E3A03

When scheduling EME contacts, which of these conditions will generally result in the least path loss?

Select	Answer
A	When the MUF is above 30 MHz
B	When the moon is full
C	When the moon is at apogee
D	When the moon is at perigee

14. - E3B03

What is the best time of day for transequatorial propagation?

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

15. - E3C04

What does the value of Bz (B sub Z) represent?

Select	Answer
A	Geomagnetic field stability
B	Duration of long-delayed echoes
C	Direction and strength of the interplanetary magnetic field
D	Critical frequency for vertical transmissions

16. - E4A10

Which of the following displays multiple digital signal states simultaneously?

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

17. - E4B08

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

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

18. - E4C14

What transmit frequency might generate an image response signal in a receiver tuned to 14.300 MHz and that uses a 455 kHz IF frequency?

Select	Answer
A	13.845 MHz
B	14.445 MHz
C	15.210 MHz
D	14.755 MHz

19. - E4D01

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

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

20. - E4E05

How can radio frequency interference from an AC motor be suppressed?

Select	Answer
A	By installing a bypass capacitor in series with the motor leads
B	By installing a high-pass filter in series with the motor's power leads
C	By installing a brute-force AC-line filter in series with the motor leads
D	By using a ground-fault current interrupter in the circuit used to power the motor

21. - E5A06

What is the magnitude of the circulating current within the components of a parallel LC circuit at resonance?

Select	Answer
A	It equals 1 divided by the quantity 2 times pi, multiplied by the square root of inductance L multiplied by capacitance C
B	It is at a maximum
C	It is at a minimum
D	It equals 2 multiplied by pi, multiplied by frequency, multiplied by inductance

22. - E5B04

What is the time constant of a circuit having two 220-microfarad capacitors and two 1-megohm resistors, all in parallel?

Select	Answer
A	220 seconds
B	440 seconds
C	55 seconds
D	110 seconds

23. - E5C12

Which point on Figure E5-1 best represents the impedance of a series circuit consisting of a 300-ohm resistor and a 19-picofarad capacitor at 21.200 MHz?

Select	Answer
A	Point 3
B	Point 8
C	Point 1
D	Point 7

24. - E5D11

What is the power factor of an RL circuit having a 60-degree phase angle between the voltage and the current?

Select	Answer
A	1.73
B	0.5
C	1.414
D	0.866

25. - E6A09

What is a depletion-mode FET?

Select	Answer
A	Any FET for which holes are the majority carriers
B	An FET that exhibits a current flow between source and drain when no gate voltage is applied
C	Any FET without a channel
D	An FET that has no current flow between source and drain when no gate voltage is applied

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 rectifier in high current power supplies
D	As a constant voltage reference in a power supply

27. - E6C08

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

Select	Answer
A	4
B	3
C	1
D	2

28. - E6D06

What core material property determines the inductance of an inductor?

Select	Answer
A	Resistance
B	Thermal impedance
C	Permeability
D	Reactivity

29. - E6E02

Which of the following device packages is a through-hole type?

Select	Answer
A	SOT
B	Ball grid array
C	DIP
D	PLCC

30. - E6F09

What is the efficiency of a photovoltaic cell?

Select	Answer
A	Cost per kilowatt-hour generated
B	The open-circuit voltage divided by the short-circuit current under full illumination
C	The output RF power divided by the input DC power
D	The relative fraction of light that is converted to current

31. - E7A09

What logical operation is performed by an exclusive NOR gate?

Select	Answer
A	It produces logic 1 at its output only if all inputs are logic 1
B	It produces logic 0 at its output only if all inputs are logic 0
C	It produces logic 0 at its output if only one input is logic 1
D	It produces logic 1 at its output if only one input is logic 1

32. - E7B18

What is a characteristic of a grounded-grid amplifier?

Select	Answer
A	Low bandwidth
B	High power gain
C	High filament voltage
D	Low input impedance

33. - E7C02

Which of the following is a property of a T-network with series capacitors and a parallel shunt inductor?

Select	Answer
A	It is a high-pass filter
B	It is a low-pass filter
C	It is a notch filter
D	It is a band-pass filter

34. - E7D09

What is the main reason to use a charge controller with a solar power system?

Select	Answer
A	Matching of day and night charge rates
B	Prevention of battery damage due to overcharge
C	Control of electrolyte levels during battery discharge
D	Prevention of battery undercharge

35. - E7E09

What occurs when an excessive amount of signal energy reaches a mixer circuit?

Select	Answer
A	A beat frequency is generated
B	Automatic limiting occurs
C	Spurious mixer products are generated
D	Mixer blanking occurs

36. - E7F13

What is the function of taps in a digital signal processing filter?

Select	Answer
A	Select the point at which baseband signals are generated
B	To reduce excess signal pressure levels
C	Provide incremental signal delays for filter algorithms
D	Provide access for debugging software

37. - E7G01

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

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

38. - E7H04

How is positive feedback supplied in a Colpitts oscillator?

Select	Answer
A	Through a tapped coil
B	Through a capacitive divider
C	Through a neutralizing capacitor
D	Through link coupling

39. - E8A03

What type of wave does a Fourier analysis show to be made up of sine waves of a given fundamental frequency plus all its harmonics?

Select	Answer
A	A cosine wave
B	A sine wave
C	A sawtooth wave
D	A square wave

40. - E8B10

What is frequency division multiplexing?

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

41. - E8C10

How may data rate be increased without increasing bandwidth?

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

42. - E8D04

What is the primary effect of extremely short rise or fall time on a CW signal?

Select	Answer
A	The generation of RF harmonics
B	More difficult to copy
C	The generation of key clicks
D	Limits data speed

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	78.7 watts
B	420 watts
C	1977 watts
D	286 watts

44. - E9B08

What is the far field of an antenna?

Select	Answer
A	The region where radiated power dissipates over a specified time period
B	The region where the shape of the antenna pattern is independent of distance
C	The region of the ionosphere where radiated power is not refracted
D	The region where radiated field strengths are constant

45. - E9C04

What happens to the radiation pattern of an unterminated long wire antenna as the wire length is increased?

Select	Answer
A	The front-to-back ratio decreases
B	The lobes align more in the direction of the wire
C	The vertical angle increases
D	The lobes become more perpendicular to the wire

46. - E9D10

What happens to feed-point impedance at the base of a fixed length HF mobile antenna when operated below its resonant frequency?

Select	Answer
A	The radiation resistance decreases and the capacitive reactance increases
B	The radiation resistance increases and the capacitive reactance decreases
C	The radiation resistance decreases and the capacitive reactance decreases
D	The radiation resistance increases and the capacitive reactance increases

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

48. - E9F12

What impedance does a 1/4-wavelength transmission line present to a generator when the line is open at the far end?

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

49. - E9G04

What are the two families of circles and arcs that make up a Smith chart?

Select	Answer
A	Voltage and impedance
B	Reactance and voltage
C	Resistance and voltage
D	Resistance and reactance

50. - E9H07

Why is RF attenuation used when direction-finding?

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

Figure E5-1

Figure E6-3