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

2. - E1A14

Except in some parts of Alaska, what is the maximum power permitted on the 630 meter band?

Select	Answer
A	50 watts PEP
B	5 watts EIRP
C	1 watt EIRP
D	100 watts PEP

3. - E1B05

What is the National Radio Quiet Zone?

Select	Answer
A	An area in Puerto Rico surrounding the Arecibo Radio Telescope
B	An area in New Mexico surrounding the White Sands Test Area
C	An area in Florida surrounding Cape Canaveral
D	An area surrounding the National Radio Astronomy Observatory

4. - E1C09

What is the highest modulation index permitted at the highest modulation frequency for angle modulation below 29.0 MHz?

Select	Answer
A	0.5
B	2.0
C	1.0
D	3.0

5. - E1D10

Which amateur stations are eligible to be telecommand stations of space stations (subject to the privileges of the class of operator license held by the control operator of the station)?

Select	Answer
A	All these choices are correct
B	Any amateur station so designated by the space station licensee
C	Any amateur station designated by NASA
D	Any amateur station so designated by the ITU

6. - E1E06

Who is responsible for the proper conduct and necessary supervision during an amateur operator license examination session?

Select	Answer
A	The VEC coordinating the session
B	The FCC
C	The VE session manager
D	Each administering VE

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	All privileges of the Amateur Extra Class license
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	The operating terms and conditions of the Canadian amateur service license, not to exceed U.S. Amateur Extra Class license privileges
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 upload operational software for the transponder
B	To relay messages between satellites
C	To delay download of telemetry between satellites
D	To store digital messages in the satellite for later download by other stations

9. - E2B09

What hardware, other than a receiver with SSB capability and a suitable computer, is needed to decode SSTV using Digital Radio Mondiale (DRM)?

Select	Answer
A	A special IF converter
B	A special front end limiter
C	No other hardware is needed
D	A special notch filter to remove synchronization pulses

10. - E2C02

Which of the following best describes the term self-spotting? in connection with HF contest operating?

Select	Answer
A	A manual technique for rapidly zero beating or tuning to a station's frequency before calling that station
B	An automatic method for rapidly zero beating or tuning to a station's frequency before calling that station
C	The acceptable practice of manually posting the call signs of stations on a spotting network
D	The often-prohibited practice of posting one's own call sign and frequency on a spotting network

11. - E2D07

What digital protocol is used by APRS?

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

12. - E2E09

Which of the following HF digital modes uses variable-length coding for bandwidth efficiency?

Select	Answer
A	PSK31
B	MT63
C	PACTOR
D	RTTY

13. - E3A11

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

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

14. - E3B02

What is the approximate maximum range for signals using transequatorial propagation?

Select	Answer
A	5000 miles
B	7500 miles
C	1000 miles
D	2500 miles

15. - E3C14

Why does the radio-path horizon distance exceed the geometric horizon?

Select	Answer
A	Downward bending due to density variations in the atmosphere
B	Due to the Doppler effect
C	D-region skip
D	E-region skip

16. - E4A05

What is the purpose of the prescaler function on a frequency counter?

Select	Answer
A	It amplifies low-level signals for more accurate counting
B	It prevents oscillation in a low-frequency counter circuit
C	It divides a higher frequency signal so a low-frequency counter can display the input frequency
D	It multiplies a higher frequency signal so a low-frequency counter can display the operating frequency

17. - E4B11

Which of the following can be measured with a vector network analyzer?

Select	Answer
A	Reflection coefficient
B	Output impedance
C	Input impedance
D	All these choices are correct

18. - E4C08

An SDR receiver is overloaded when input signals exceed what level?

Select	Answer
A	The maximum count value of the analog-to-digital converter
B	The reference voltage of the analog-to-digital converter
C	One-half the maximum sample rate
D	One-half the maximum sampling buffer size

19. - E4D08

What causes intermodulation in an electronic circuit?

Select	Answer
A	Positive feedback
B	Nonlinear circuits or devices
C	Lack of neutralization
D	Too little gain

20. - E4E11

What could cause local AM broadcast band signals to combine to generate spurious signals in the MF or HF bands?

Select	Answer
A	One or more of the broadcast stations is transmitting an over-modulated signal
B	You are receiving skywave signals from a distant station
C	Your station receiver IF amplifier stage is defective
D	Nearby corroded metal joints are mixing and re-radiating the broadcast signals

21. - E5A11

What is the half-power bandwidth of a resonant circuit that has a resonant frequency of 7.1 MHz and a Q of 150?

Select	Answer
A	315.6 Hz
B	23.67 kHz
C	157.8 Hz
D	47.3 kHz

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	One time constant
C	A time factor of one
D	One exponential period

23. - E5C03

Which of the following represents an inductive reactance in polar coordinates?

Select	Answer
A	A negative magnitude
B	A positive phase angle
C	A negative phase angle
D	A positive magnitude

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 apparent power by the power factor
B	By multiplying the reactive power by the power factor
C	By dividing the reactive 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 switching speed
B	The change in collector current with respect to base current
C	The frequency at which the current gain is reduced to 0.707
D	The breakdown voltage of the base to collector junction

26. - E6B07

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

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

27. - E6C07

What best describes a pull-up or pull-down resistor?

Select	Answer
A	A resistor that ensures that an oscillator frequency does not drift
B	A resistor connected to an op-amp output that prevents signals from exceeding the power supply voltage
C	A resistor in a keying circuit used to reduce key clicks
D	A resistor connected to the positive or negative supply line used to establish a voltage when an input or output is an open circuit

28. - E6D08

What is one reason for using powdered-iron cores rather than ferrite cores in an inductor?

Select	Answer
A	Powdered-iron cores generally maintain their characteristics at higher currents
B	Powdered-iron cores use smaller diameter wire for the same inductance
C	Powdered-iron cores generally require fewer turns to produce a given inductance
D	Powdered-iron cores generally have greater initial permeability

29. - E6E03

Which of the following materials is likely to provide the highest frequency of operation when used in MMICs?

Select	Answer
A	Silicon
B	Gallium nitride
C	Silicon dioxide
D	Silicon nitride

30. - E6F02

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

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

31. - E7A06

What is a characteristic of a monostable multivibrator?

Select	Answer
A	It switches momentarily to the opposite binary state and then returns to its original state after a set time
B	It maintains a constant output voltage, regardless of variations in the input voltage
C	It stores one bit of data in either a 0 or 1 state
D	It produces a continuous square wave oscillating between 1 and 0

32. - E7B05

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

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

33. - E7C09

What is a crystal lattice filter?

Select	Answer
A	An audio filter made with four quartz crystals that resonate at 1 kHz intervals
B	A filter using lattice-shaped quartz crystals for high-Q performance
C	A filter with narrow bandwidth and steep skirts made using quartz crystals
D	A power supply filter made with interlaced quartz crystals

34. - E7D03

What device is typically used as a stable voltage reference in a linear voltage regulator?

Select	Answer
A	A tunnel diode
B	A varactor diode
C	A Zener diode
D	An SCR

35. - E7E07

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

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

36. - E7F06

What is the minimum number of bits required for an analog-to-digital converter to sample a signal with a range of 1 volt at a resolution of 1 millivolt?

Select	Answer
A	4 bits
B	10 bits
C	8 bits
D	6 bits

37. - E7G04

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

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

38. - E7H03

How is positive feedback supplied in a Hartley oscillator?

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

39. - E8A02

Which of the following is a type of analog-to-digital conversion?

Select	Answer
A	Successive approximation
B	Level shifting
C	Phase reversal
D	Harmonic regeneration

40. - E8B07

Orthogonal Frequency Division Multiplexing is a technique used for which type of amateur communication?

Select	Answer
A	Extremely low-power contacts
B	EME
C	High-speed digital modes
D	OFDM signals are not allowed on amateur bands

41. - E8C04

What technique minimizes the bandwidth of a PSK31 signal?

Select	Answer
A	Use of trapezoidal data pulses
B	Use of sinusoidal data pulses
C	Zero-sum character encoding
D	Reed-Solomon character encoding

42. - E8D09

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

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

43. - E9A11

Which of the following factors determines ground losses for a ground-mounted vertical antenna operating in the 3 MHz to 30 MHz range?

Select	Answer
A	The standing wave ratio
B	Take-off angle
C	Soil conductivity
D	Distance from the transmitter

44. - E9B11

What is a disadvantage of decreasing the number of wire segments in an antenna model below 10 segments per half-wavelength?

Select	Answer
A	The antenna will become mechanically unstable
B	The computed feed point impedance may be incorrect
C	Ground conductivity will not be accurately modeled
D	The resulting design will favor radiation of harmonic energy

45. - E9C06

What is the effect of adding a terminating resistor to a rhombic antenna?

Select	Answer
A	It changes the radiation pattern from horizontal to vertical polarization
B	It reflects the standing waves on the antenna elements back to the transmitter
C	It changes the radiation pattern from bidirectional to unidirectional
D	It decreases the ground loss

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 decreases
B	The radiation resistance decreases and the capacitive reactance increases
C	The radiation resistance increases 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 epsilon match
B	The stub match
C	The delta match
D	The gamma match

48. - E9F09

What is the approximate physical length of a foam polyethylene dielectric coaxial transmission line that is electrically 1/4 wavelength long at 7.2 MHz?

Select	Answer
A	8.3 meters
B	5.2 meters
C	10.4 meters
D	6.9 meters

49. - E9G06

On the Smith chart shown in Figure E9-3, what is the name for the large outer circle on which the reactance arcs terminate?

Select	Answer
A	Impedance axis
B	Reactance axis
C	Polar axis
D	Prime axis

50. - E9H09

What is a Pennant antenna?

Select	Answer
A	A stealth antenna built to look like a flagpole
B	A form of rhombic antenna terminated in a variable capacitor to provide frequency diversity
C	A four-element, high-gain vertical array invented by George Pennant
D	A small, vertically oriented receiving antenna consisting of a triangular loop terminated in approximately 900 ohms

Figure E9-3