US Amateur Radio - Amateur Extra (Element 4, 2016-2020) Practice Test

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1. - E1A04

With your transceiver displaying the carrier frequency of phone signals, you hear a DX station calling CQ on 3.601 MHz LSB. Is it legal to return the call using lower sideband on the same frequency?

Select	Answer
A	Yes, because the DX station initiated the contact
B	No, the sideband will extend beyond the edge of the phone band segment
C	No, U.S. stations are not permitted to use phone emissions below 3.610 MHz
D	Yes, because the displayed frequency is within the 75 meter phone band segment

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

3. - E1C10

What types of amateur stations may automatically retransmit the radio signals of other amateur stations?

Select	Answer
A	Only auxiliary, beacon or space stations
B	Only beacon, repeater or space stations
C	Only earth stations, repeater stations or model craft
D	Only auxiliary, repeater or space stations

4. - E1D04

What is an Earth station in the amateur satellite service?

Select	Answer
A	An amateur station that is not able to communicate using amateur satellites
B	Any amateur station on the surface of the Earth
C	An amateur station that transmits telemetry consisting of measurement of upper atmosphere
D	An amateur station within 50 km of the Earth's surface intended for communications with amateur stations by means of objects in space

5. - 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	The FCC
C	Each administering VE
D	The VEC coordinating the session

6. - E1F10

What is the maximum permitted transmitter peak envelope power for an amateur station transmitting spread spectrum communications?

Select	Answer
A	1.5 kW
B	10 W
C	1.5 W
D	1 W

7. - E2A13

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

Select	Answer
A	Geostationary
B	LEO
C	HEO
D	Geomagnetic

8. - E2B07

What is the name of the signal component that carries color information in NTSC video?

Select	Answer
A	Chroma
B	Spectral Intensity
C	Hue
D	Luminance

9. - E2C08

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

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

10. - E2D03

Which of the following digital modes is especially useful for EME communications?

Select	Answer
A	PACTOR III
B	JT65
C	Olivia
D	FSK441

11. - E2E01

Which type of modulation is common for data emissions below 30 MHz?

Select	Answer
A	Pulse modulation
B	Spread spectrum
C	DTMF tones modulating an FM signal
D	FSK

12. - E3A06

Which of the following is required for microwave propagation via rain scatter?

Select	Answer
A	Rain droplets must be electrically charged
B	Rain droplets must be within the E layer
C	The rain must be within radio range of both stations
D	All of these choices are correct

13. - E3B07

Which of the following could account for hearing an echo on the received signal of a distant station?

Select	Answer
A	High D layer absorption
B	Meteor scatter
C	Transmit frequency is higher than the MUF
D	Receipt of a signal by more than one path

14. - E3C07

Which of the following descriptors indicates the greatest solar flare intensity?

Select	Answer
A	Class A
B	Class X
C	Class M
D	Class B

15. - E4A07

Which of the following is an advantage of using an antenna analyzer compared to an SWR bridge to measure antenna SWR?

Select	Answer
A	Antenna analyzers automatically tune your antenna for resonance
B	Antenna analyzers display a time-varying representation of the modulation envelope
C	All of these choices are correct
D	Antenna analyzers do not need an external RF source

16. - E4B04

If a frequency counter with a specified accuracy of +/- 0.1 ppm reads 146,520,000 Hz, what is the most the actual frequency being measured could differ from the reading?

Select	Answer
A	14.652 Hz
B	0.1 MHz
C	1.4652 Hz
D	1.4652 kHz

17. - E4C09

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

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

18. - E4D02

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

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

19. - E4E05

How can noise from an electric motor be suppressed?

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

20. - E5A03

What is the magnitude of the impedance of a series RLC circuit at resonance?

Select	Answer
A	High, as compared to the circuit resistance
B	Approximately equal to capacitive reactance
C	Approximately equal to inductive reactance
D	Approximately equal to circuit resistance

21. - E5B10

What is the relationship between the current through an inductor and the voltage across an inductor?

Select	Answer
A	Voltage and current are 180 degrees out of phase
B	Voltage and current are in phase
C	Voltage leads current by 90 degrees
D	Current leads voltage by 90 degrees

22. - E5C10

When using rectangular coordinates to graph the impedance of a circuit, what does the vertical axis represent?

Select	Answer
A	Reactive component
B	The difference between the resistive and reactive components
C	Resistive component
D	The sum of the reactive and resistive components

23. - E5D12

How many watts are consumed in a circuit having a power factor of 0.2 if the input is 100-VAC at 4 amperes?

Select	Answer
A	50 watts
B	2000 watts
C	80 watts
D	400 watts

24. - E6A10

In Figure E6-2, what is the schematic symbol for an N-channel dual-gate MOSFET?

Select	Answer
A	2
B	6
C	5
D	4

25. - E6B06

Which of the following is a common use of a hot-carrier diode?

Select	Answer
A	As a constant voltage reference in a power supply
B	As a VHF/UHF mixer or detector
C	As balanced mixers in FM generation
D	As a variable capacitance in an automatic frequency control circuit

26. - E6C10

In Figure E6-5, what is the schematic symbol for a NOR gate?

Select	Answer
A	2
B	3
C	4
D	1

27. - E6D13

What is the primary cause of inductor self-resonance?

Select	Answer
A	Inductive kickback
B	The skin effect
C	Non-linear core hysteresis
D	Inter-turn capacitance

28. - E6E02

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

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

29. - E6F13

What is a liquid crystal display (LCD)?

Select	Answer
A	A frequency-determining unit for a transmitter or receiver
B	A modern replacement for a quartz crystal oscillator which displays its fundamental frequency
C	A display utilizing a crystalline liquid and polarizing filters which becomes opaque when voltage is applied
D	A display that uses a glowing liquid to remain brightly lit in dim light

30. - E7A10

What is a truth table?

Select	Answer
A	A diagram showing logic states when the digital device output is true
B	A list of inputs and corresponding outputs for a digital device
C	A table of logic symbols that indicate the high logic states of an op-amp
D	A table of logic symbols that indicate the logic states of an op-amp

31. - E7B04

Where on the load line of a Class A common emitter amplifier would bias normally be set?

Select	Answer
A	At a point where the bias resistor equals the load resistor
B	Approximately half-way between saturation and cutoff
C	At a point where the load line intersects the zero bias current curve
D	Where the load line intersects the voltage axis

32. - E7C15

What is a crystal lattice filter?

Select	Answer
A	A power supply filter made with interlaced quartz crystals
B	A filter with narrow bandwidth and steep skirts made using quartz crystals
C	A filter with wide bandwidth and shallow skirts made using quartz crystals
D	An audio filter made with four quartz crystals that resonate at 1kHz intervals

33. - E7D08

What type of circuit is shown in Figure E7-3?

Select	Answer
A	Grounded emitter amplifier
B	Linear voltage regulator
C	Emitter follower
D	Switching voltage regulator

34. - E7E07

What is meant by the term baseband in radio communications?

Select	Answer
A	The lowest frequency band that the transmitter or receiver covers
B	The frequency components present in the modulating signal
C	The basic oscillator frequency in an FM transmitter that is multiplied to increase the deviation and carrier frequency
D	The unmodulated bandwidth of the transmitted signal

35. - E7F08

What is the function of decimation with regard to digital filters?

Select	Answer
A	Removing unnecessary significant digits
B	Converting data to binary code decimal form
C	Reducing the effective sample rate by removing samples
D	Attenuating the signal

36. - E7G04

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

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

37. - E7H14

What is a phase-locked loop circuit?

Select	Answer
A	An electronic circuit also known as a monostable multivibrator
B	An electronic servo loop consisting of a phase detector, a low-pass filter, a voltage-controlled oscillator, and a stable reference oscillator
C	An electronic servo loop consisting of a ratio detector, reactance modulator, and voltage-controlled oscillator
D	An electronic circuit consisting of a precision push-pull amplifier with a differential input

38. - E8A08

Why would a direct or flash conversion analog-to-digital converter be useful for a software defined radio?

Select	Answer
A	Very high speed allows digitizing high frequencies
B	All of these choices are correct
C	Immunity to out of sequence coding reduces spurious responses
D	Very low power consumption decreases frequency drift

39. - E8B10

What describes frequency division multiplexing?

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

40. - E8C08

How does ARQ accomplish error correction?

Select	Answer
A	Special binary codes provide automatic correction
B	If errors are detected, redundant data is substituted
C	If errors are detected, a retransmission is requested
D	Special polynomial codes provide automatic correction

41. - E8D06

Which of the following indicates likely overmodulation of an AFSK signal such as PSK or MFSK?

Select	Answer
A	Rapid signal fading
B	Strong ALC action
C	High reflected power
D	Harmonics on higher bands

42. - E9A15

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	286 watts
B	78.7 watts
C	420 watts
D	1977 watts

43. - E9B03

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

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

44. - E9C11

How is the far-field elevation pattern of a vertically polarized antenna affected by being mounted over seawater versus rocky ground?

Select	Answer
A	The low-angle radiation decreases
B	Both the high-angle and low-angle radiation decrease
C	The low-angle radiation increases
D	The high-angle radiation increases

45. - E9D07

What is an advantage of using top loading in a shortened HF vertical antenna?

Select	Answer
A	Higher losses
B	Lower Q
C	Improved radiation efficiency
D	Greater structural strength

46. - E9E06

What is the equivalent lumped-constant network for a hairpin matching system of a 3-element Yagi?

Select	Answer
A	Pi-network
B	A shunt inductor
C	Pi-L-network
D	A series capacitor

47. - E9F04

What is the typical velocity factor for a coaxial cable with solid polyethylene dielectric?

Select	Answer
A	0.30
B	2.70
C	0.66
D	0.10

48. - E9G02

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

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

49. - E9H08

What is the function of a sense antenna?

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

50. - E0A06

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

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

Figure E6-2

Figure E6-5

Figure E7-3

Figure E9-1