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

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1. - E0A11

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

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

2. - E1A03

What is the maximum legal carrier frequency on the 20 meter band for transmitting USB AFSK digital signals having a 1 kHz bandwidth?

Select	Answer
A	14.349 MHz
B	14.149 MHz
C	14.100 MHz
D	14.070 MHz

3. - E1B11

What does PRB-1 require of regulations affecting amateur radio?

Select	Answer
A	Reasonable accommodations of amateur radio must be made
B	Use of wireless devices in a vehicle is exempt from regulation
C	Amateur radio operations must be permitted in any private residence
D	No limitations may be placed on antenna size or placement

4. - E1C07

At what level below a signal's mean power level is its bandwidth determined according to FCC rules?

Select	Answer
A	23 dB
B	3 dB
C	26 dB
D	6 dB

5. - E1D11

Which amateur stations are eligible to operate as Earth stations?

Select	Answer
A	Only those of General, Advanced or Amateur Extra Class operators
B	Any amateur station, subject to the privileges of the class of operator license held by the control operator
C	Any amateur station whose licensee has filed a pre-space notification with the FCC's International Bureau
D	Only those of Amateur Extra Class operators

6. - E1E10

What must the administering VEs do after the administration of a successful examination for an amateur operator license?

Select	Answer
A	They must submit the application document to the coordinating VEC according to the coordinating VEC instructions
B	They must collect and send the documents to the FCC according to instructions
C	They must collect and submit the documents to the coordinating VEC for grading
D	They must collect and send the documents to the NCVEC for grading

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	None, they must obtain a U.S. license
D	The operating terms and conditions of the Canadian amateur service license, not to exceed U.S. Amateur Extra Class license privileges

8. - E2A06

What are Keplerian elements?

Select	Answer
A	High-emission heater filaments used in magnetron tubes
B	Parameters that define the orbit of a satellite
C	Encrypting codes used for spread spectrum modulation
D	Phase reversing elements in a Yagi antenna

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	A special notch filter to remove synchronization pulses
D	No other hardware is needed

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. - E2D05

What is one advantage of the JT65 mode?

Select	Answer
A	Uses only a 65 Hz bandwidth
B	Permits fast-scan TV transmissions over narrow bandwidth
C	Easily copied by ear if necessary
D	The ability to decode signals which have a very low signal-to-noise ratio

12. - E2E09

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

Select	Answer
A	PACTOR
B	MT63
C	RTTY
D	PSK31

13. - E3A07

Atmospheric ducts capable of propagating microwave signals often form over what geographic feature?

Select	Answer
A	Bodies of water
B	Forests
C	Urban areas
D	Mountain ranges

14. - E3B10

Why is chordal hop propagation desirable?

Select	Answer
A	Atmospheric noise is lower in the direction of chordal hop propagation
B	The signal experiences less loss compared to multi-hop using Earth as a reflector
C	Signals travel faster along ionospheric chords
D	The MUF for chordal hop propagation is much lower than for normal skip propagation

15. - E3C14

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

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

16. - E4A05

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

Select	Answer
A	It prevents oscillation in a low-frequency counter circuit
B	It amplifies low-level signals for more accurate counting
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. - E4B06

How much power is being absorbed by the load when a directional power meter connected between a transmitter and a terminating load reads 100 watts forward power and 25 watts reflected power?

Select	Answer
A	75 watts
B	125 watts
C	100 watts
D	25 watts

18. - E4C09

Which of the following choices is a good reason for selecting a high frequency for the design of the IF in a superheterodyne HF or VHF communications receiver?

Select	Answer
A	Fewer components in the receiver
B	Improved receiver noise figure
C	Easier for front-end circuitry to eliminate image responses
D	Reduced drift

19. - E4D04

Which of the following may reduce or eliminate intermodulation interference in a repeater caused by another transmitter operating in close proximity?

Select	Answer
A	Utilizing a Class D final amplifier
B	A properly terminated circulator at the output of the repeater's transmitter
C	Utilizing a Class C final amplifier
D	A band-pass filter in the feed line between the transmitter and receiver

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 appear across a wide bandwidth
D	Signals that have a sharply peaked frequency distribution

21. - E5A02

What is resonance in an LC or RLC circuit?

Select	Answer
A	The highest frequency that will pass current
B	The frequency at which the reactive impedance equals the resistive impedance
C	The frequency at which the capacitive reactance equals the inductive reactance
D	The lowest frequency that will pass current

22. - E5B08

What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 100 ohms, R is 100 ohms, and XL is 75 ohms?

Select	Answer
A	76 degrees with the voltage leading the current
B	14 degrees with the voltage leading the current
C	14 degrees with the voltage lagging the current
D	76 degrees with the voltage lagging the current

23. - E5C04

What coordinate system is often used to display the resistive, inductive, and/or capacitive reactance components of impedance?

Select	Answer
A	Elliptical coordinates
B	Maidenhead grid
C	Faraday grid
D	Rectangular coordinates

24. - E5D14

What is reactive power?

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

25. - E6A05

How does DC input impedance at the gate of a field-effect transistor compare with the DC input impedance of a bipolar transistor?

Select	Answer
A	They are both high impedance
B	An FET has lower input impedance
C	An FET has higher input impedance
D	They are both low impedance

26. - E6B08

Which of the following is a Schottky barrier diode?

Select	Answer
A	Thermionic emission diode
B	PIN junction
C	Metal-semiconductor junction
D	Electrolytic rectifier

27. - E6C04

Which of the following is an advantage of BiCMOS logic?

Select	Answer
A	All these choices are correct
B	Its simplicity results in much less expensive devices than standard CMOS
C	It is immune to electrostatic damage
D	It has the high input impedance of CMOS and the low output impedance of bipolar transistors

28. - E6D09

What devices are commonly used as VHF and UHF parasitic suppressors at the input and output terminals of a transistor HF amplifier?

Select	Answer
A	Electrolytic capacitors
B	Ferrite beads
C	Steel-core toroids
D	Butterworth filters

29. - E6E08

How is power supplied to the most common type of MMIC?

Select	Answer
A	Directly to the bias voltage (VCC IN) lead
B	Through a resistor and/or RF choke connected to the amplifier output lead
C	MMICs require no operating bias
D	Through a capacitor and RF choke connected to the amplifier input lead

30. - E6F11

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

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

31. - E7A07

What logical operation does a NAND gate perform?

Select	Answer
A	It produces logic 0 at its output if some but not all inputs are logic 1
B	It produces logic 0 at its output only when all inputs are logic 0
C	It produces logic 1 at its output only when all inputs are logic 1
D	It produces logic 0 at its output only when all inputs are logic 1

32. - E7B08

How can an RF power amplifier be neutralized?

Select	Answer
A	By increasing the driving power
B	By feeding an in-phase component of the output back to the input
C	By reducing the driving power
D	By feeding a 180-degree out-of-phase portion of the output back to the input

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

34. - E7D09

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

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

35. - E7E02

What is the function of a reactance modulator?

Select	Answer
A	To produce AM signals by using an electrically variable resistance
B	To produce AM signals by using an electrically variable inductance or capacitance
C	To produce PM signals by using an electrically variable resistance
D	To produce PM or FM signals by using an electrically variable inductance or capacitance

36. - E7F13

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

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

37. - E7G09

What will be the output voltage of the circuit shown in Figure E7-3 if R1 is 1000 ohms, RF is 10,000 ohms, and 0.23 volts DC is applied to the input?

Select	Answer
A	-0.23 volts
B	0.23 volts
C	-2.3 volts
D	2.3 volts

38. - E7H04

How is positive feedback supplied in a Colpitts oscillator?

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

39. - E8A06

What is the approximate ratio of PEP-to-average power in a typical single-sideband phone signal?

Select	Answer
A	25 to 1
B	2.5 to 1
C	1 to 1
D	100 to 1

40. - E8B04

What is the modulation index of an FM-phone signal having a maximum carrier deviation of plus or minus 6 kHz when modulated with a 2 kHz modulating frequency?

Select	Answer
A	3
B	2000
C	1/3
D	6000

41. - E8C10

How may data rate be increased without increasing bandwidth?

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

42. - E8D07

What is a common cause of overmodulation of AFSK signals?

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

43. - E9A03

What is the radiation resistance of an antenna?

Select	Answer
A	The value of a resistance that would dissipate the same amount of power as that radiated from an antenna
B	The resistance in the atmosphere that an antenna must overcome to be able to radiate a signal
C	The combined losses of the antenna elements and feed line
D	The specific impedance of the antenna

44. - E9B10

What is the principle of a Method of Moments analysis?

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

45. - E9C08

What is a folded dipole antenna?

Select	Answer
A	A half-wave dipole with an additional parallel wire connecting its two ends
B	A type of ground-plane antenna
C	A dipole configured to provide forward gain
D	A dipole one-quarter wavelength long

46. - E9D01

How much does the gain of an ideal parabolic dish antenna change when the operating frequency is doubled?

Select	Answer
A	6 dB
B	3 dB
C	2 dB
D	4 dB

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

48. - E9F03

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

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

49. - E9G08

What is the process of normalization with regard to a Smith chart?

Select	Answer
A	Reassigning impedance values with regard to the prime center
B	Reassigning resistance values with regard to the reactance axis
C	Reassigning reactance values with regard to the resistance axis
D	Reassigning prime center with regard to the reactance axis

50. - E9H05

What is the main drawback of a small wire-loop antenna for direction finding?

Select	Answer
A	It is practical for use only on VHF and higher bands
B	It has no clearly defined null
C	All these choices are correct
D	It has a bidirectional pattern

Figure E7-3