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

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1. - E0A06

Why are there separate electric (E) and magnetic (H) field MPE limits?

Select	Answer
A	Ground reflections and scattering make the field strength vary with location
B	All these choices are correct
C	The body reacts to electromagnetic radiation from both the E and H fields
D	E field and H field radiation intensity peaks can occur at different locations

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

3. - E1B02

Which of the following is an acceptable bandwidth for Digital Radio Mondiale (DRM) based voice or SSTV digital transmissions made on the HF amateur bands?

Select	Answer
A	10 kHz
B	3 kHz
C	20 kHz
D	15 kHz

4. - E1C02

Which of the following types of communications may be transmitted to amateur stations in foreign countries?

Select	Answer
A	Messages intended for users of the maritime satellite service
B	All these choices are correct
C	Communications incidental to the purpose of the amateur service and remarks of a personal nature
D	Business-related messages for non-profit organizations

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

6. - E1E06

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

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

7. - E1F09

Which of the following conditions apply when transmitting spread spectrum emissions?

Select	Answer
A	A station transmitting SS emission must not cause harmful interference to other stations employing other authorized emissions
B	The transmission must not be used to obscure the meaning of any communication
C	All these choices are correct
D	The transmitting station must be in an area regulated by the FCC or in a country that permits SS emissions

8. - E2A03

How is the signal inverted by an inverting linear transponder?

Select	Answer
A	The signal is passed through a mixer and the difference rather than the sum is transmitted
B	The signal is passed through a non-linear filter
C	The signal is reduced to I and Q components and the Q component is filtered out
D	The signal is detected and remodulated on the reverse sideband

9. - E2B06

What is vestigial sideband modulation?

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

10. - E2C04

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

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

11. - E2D09

What type of modulation is used for JT65 contacts?

Select	Answer
A	IEEE 802.11
B	Multi-tone AFSK
C	PSK
D	RTTY

12. - E2E05

Which of these digital modes does not support keyboard-to-keyboard operation?

Select	Answer
A	PSK31
B	RTTY
C	MFSK
D	PACTOR

13. - E3A09

Which of the following frequency ranges is most suited for meteor scatter communications?

Select	Answer
A	220 MHz - 450 MHz
B	28 MHz - 148 MHz
C	1.8 MHz - 1.9 MHz
D	10 MHz - 14 MHz

14. - E3B12

What is the primary characteristic of chordal hop propagation?

Select	Answer
A	Successive ionospheric refractions without an intermediate reflection from the ground
B	Propagation away from the great circle bearing between stations
C	Propagation across the geomagnetic equator
D	Signals reflected back toward the transmitting station

15. - E3C15

What might be indicated by a sudden rise in radio background noise across a large portion of the HF spectrum?

Select	Answer
A	Increased transequatorial propagation is likely
B	A solar flare has occurred
C	Long-path propagation is likely
D	A temperature inversion has occurred

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. - E4B09

What is indicated if the current reading on an RF ammeter placed in series with the antenna feed line of a transmitter increases as the transmitter is tuned to resonance?

Select	Answer
A	There is more power going into the antenna
B	There is an impedance mismatch between the antenna and feed line
C	There is possibly a short to ground in the feed line
D	The transmitter is not properly neutralized

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	14.445 MHz
B	15.210 MHz
C	13.845 MHz
D	14.755 MHz

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	A band-pass filter in the feed line between the transmitter and receiver
D	Utilizing a Class C final amplifier

20. - E4E07

Which of the following can cause shielded cables to radiate or receive interference?

Select	Answer
A	Low inductance ground connections at both ends of the shield
B	Use of braided shielding material
C	Tying all ground connections to a common point resulting in differential-mode currents in the shield
D	Common-mode currents on the shield and conductors

21. - E5A01

What can cause the voltage across reactances in a series RLC circuit to be higher than the voltage applied to the entire circuit?

Select	Answer
A	Resistance
B	Resonance
C	Conductance
D	Capacitance

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

23. - E5C08

What coordinate system is often used to display the phase angle of a circuit containing resistance, inductive and/or capacitive reactance?

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

24. - E5D06

In what direction is the magnetic field oriented about a conductor in relation to the direction of electron flow?

Select	Answer
A	In all directions; omni-directional
B	In a circle around the conductor
C	In a direction opposite to the current
D	In the same direction as the current

25. - E6A12

Why do many MOSFET devices have internally connected Zener diodes on the gates?

Select	Answer
A	To protect the substrate from excessive voltages
B	To reduce the chance of static damage to the gate
C	To provide a voltage reference for the correct amount of reverse-bias gate voltage
D	To keep the gate voltage within specifications and prevent the device from overheating

26. - E6B10

In Figure E6-2, what is the schematic symbol for a light-emitting diode?

Select	Answer
A	6
B	7
C	1
D	5

27. - E6C06

Why do CMOS digital integrated circuits have high immunity to noise on the input signal or power supply?

Select	Answer
A	The input switching threshold is about two times the power supply voltage
B	Large bypass capacitance is inherent
C	Bandwidth is very limited
D	The input switching threshold is about one-half the power supply voltage

28. - E6D07

What is current in the primary winding of a transformer called if no load is attached to the secondary?

Select	Answer
A	Excitation current
B	Magnetizing current
C	Stabilizing current
D	Direct current

29. - E6E03

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

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

30. - E6F01

What absorbs the energy from light falling on a photovoltaic cell?

Select	Answer
A	Protons
B	Electrons
C	Photons
D	Holes

31. - E7A03

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

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

32. - E7B08

How can an RF power amplifier be neutralized?

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

33. - E7C09

What is a crystal lattice filter?

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

34. - E7D10

What is the primary reason that a high-frequency switching type high-voltage power supply can be both less expensive and lighter in weight than a conventional power supply?

Select	Answer
A	The inverter design does not require any output filtering
B	It uses a diode bridge rectifier for increased output
C	The high frequency inverter design uses much smaller transformers and filter components for an equivalent power output
D	It uses a large power factor compensation capacitor to recover power from the unused portion of the AC cycle

35. - E7E09

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

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

36. - E7F03

What type of digital signal processing filter is used to generate an SSB signal?

Select	Answer
A	An elliptical filter
B	A notch filter
C	A Hilbert-transform filter
D	An adaptive filter

37. - E7G07

What magnitude of voltage gain can be expected from the circuit in Figure E73 when R1 is 10 ohms and RF is 470 ohms?

Select	Answer
A	47
B	0.21
C	24
D	94

38. - E7H02

What is a microphonic?

Select	Answer
A	Excess loading of the microphone by an oscillator
B	Changes in oscillator frequency due to mechanical vibration
C	An IC used for amplifying microphone signals
D	Distortion caused by RF pickup on the microphone cable

39. - E8A09

How many different input levels can be encoded by an analog-to-digital converter with 8-bit resolution?

Select	Answer
A	8 multiplied by the gain of the input amplifier
B	256
C	8
D	256 divided by the gain of the input amplifier

40. - E8B02

How does the modulation index of a phase-modulated emission vary with RF carrier frequency?

Select	Answer
A	It varies with the square root of the RF carrier frequency
B	It does not depend on the RF carrier frequency
C	It increases as the RF carrier frequency increases
D	It decreases as the RF carrier frequency increases

41. - E8C12

What factors affect the bandwidth of a transmitted CW signal?

Select	Answer
A	All these choices are correct
B	Keying speed and shape factor (rise and fall time)
C	Modulation index and output power
D	IF bandwidth and Q

42. - E8D09

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

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

43. - E9A13

What term describes station output, taking into account all gains and losses?

Select	Answer
A	Apparent power
B	Power factor
C	Half-power bandwidth
D	Effective radiated power

44. - E9B03

In the antenna radiation pattern shown in Figure E9-1, what is the front-to-side ratio?

Select	Answer
A	14 dB
B	12 dB
C	24 dB
D	18 dB

45. - E9C07

What is the approximate feed point impedance at the center of a two-wire folded dipole antenna?

Select	Answer
A	300 ohms
B	72 ohms
C	450 ohms
D	50 ohms

46. - E9D03

Where should a high Q loading coil be placed to minimize losses in a shortened vertical antenna?

Select	Answer
A	As low as possible on the vertical radiator
B	Near the center of the vertical radiator
C	At a voltage node
D	As close to the transmitter as possible

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

48. - E9F05

What is the approximate physical length of a solid polyethylene dielectric coaxial transmission line that is electrically 1/4 wavelength long at 14.1 MHz?

Select	Answer
A	5.3 meters
B	4.3 meters
C	10.6 meters
D	3.5 meters

49. - E9G04

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

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

50. - E9H05

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

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

Figure E6-2

Figure E9-1