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

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1. - E1A03

With your transceiver displaying the carrier frequency of phone signals, you hear a station calling CQ on 14.349 MHz USB. Is it legal to return the call using upper sideband on the same frequency?

Select	Answer
A	No, the sideband will extend beyond the band edge
B	No, U.S. stations are not permitted to use phone emissions above 14.340 MHz
C	Yes, because the displayed frequency is within the 20 meter band
D	Yes, because you were not the station calling CQ

2. - E1B10

What frequencies are authorized to an amateur station operating under RACES rules?

Select	Answer
A	Military Auxiliary Radio System (MARS) channels
B	Specific segments in the amateur service MF, HF, VHF and UHF bands
C	Specific local government channels
D	All amateur service frequencies authorized to the control operator

3. - E1C13

Which of the following is required in order to operate in accordance with CEPT rules in foreign countries where permitted?

Select	Answer
A	You must identify in the official language of the country in which you are operating
B	The U.S. embassy must approve of your operation
C	You must append "/CEPT" to your call sign
D	You must bring a copy of FCC Public Notice DA 11-221

4. - E1D06

Which of the following is a requirement of a space station?

Select	Answer
A	The space station must be capable of terminating transmissions by telecommand when directed by the FCC
B	The space station must be capable of changing its orbit whenever such a change is ordered by NASA
C	All of these choices are correct
D	The space station must cease all transmissions after 5 years

5. - E1E13

Which of these choices is an acceptable method for monitoring the applicants if a VEC opts to conduct an exam session remotely?

Select	Answer
A	Record the exam session on video tape for later review by the VE team
B	Have each applicant sign an affidavit stating that all session rules were followed
C	The exam proctor observes the applicants and reports any violations
D	Use a real-time video link and the Internet to connect the exam session to the observing VEs

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	1.5 W
C	1 W
D	10 W

7. - E2A14

What technology is used to track, in real time, balloons carrying amateur radio transmitters?

Select	Answer
A	Bandwidth compressed LORAN
B	Doppler shift of beacon signals
C	APRS
D	Radar

8. - E2B12

How are analog SSTV images typically transmitted on the HF bands?

Select	Answer
A	Varying tone frequencies representing the video are transmitted using PSK
B	Varying tone frequencies representing the video are transmitted using single sideband
C	Video is converted to equivalent Baudot representation
D	Video is converted to equivalent ASCII representation

9. - E2C12

What might help to restore contact when DX signals become too weak to copy across an entire HF band a few hours after sunset?

Select	Answer
A	Switch to a lower frequency HF band
B	Wait 24 hours before attempting another communication on the band
C	Switch to a higher frequency HF band
D	Wait 90 minutes or so for the signal degradation to pass

10. - E2D11

Which of the following data are used by the APRS network to communicate your location?

Select	Answer
A	Radio direction finding spectrum analysis
B	Time and frequency
C	Latitude and longitude
D	Polar coordinates

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. - E3A17

What is meant by circularly polarized electromagnetic waves?

Select	Answer
A	Waves that circle the Earth
B	Waves with an electric field bent into a circular shape
C	Waves produced by a loop antenna
D	Waves with a rotating electric field

13. - E3B11

At what time of day is Sporadic-E propagation most likely to occur?

Select	Answer
A	Any time
B	Early evening
C	Around sunrise
D	Around sunset

14. - E3C05

What orientation of Bz (B sub z) increases the likelihood that incoming particles from the Sun will cause disturbed conditions?

Select	Answer
A	Southward
B	Eastward
C	Westward
D	Northward

15. - E4A04

What determines the upper frequency limit for a computer soundcard-based oscilloscope program?

Select	Answer
A	All of these choices are correct
B	Analog-to-digital conversion speed of the soundcard
C	Q of the interface of the interface circuit
D	Amount of memory on the soundcard

16. - E4B02

What is an advantage of using a bridge circuit to measure impedance?

Select	Answer
A	It is very precise in obtaining a signal null
B	It is relatively immune to drift in the signal generator source
C	It can display results directly in Smith chart format
D	It provides an excellent match under all conditions

17. - E4C11

Which of the following is a desirable amount of selectivity for an amateur SSB phone receiver?

Select	Answer
A	4.2 kHz
B	2.4 kHz
C	4.8 kHz
D	1 kHz

18. - E4D06

What is the term for unwanted signals generated by the mixing of two or more signals?

Select	Answer
A	Amplifier desensitization
B	Neutralization
C	Adjacent channel interference
D	Intermodulation interference

19. - E4E05

How can noise from an electric motor be suppressed?

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

20. - E5A04

What is the magnitude of the impedance of a circuit with a resistor, an inductor and a capacitor all in parallel, at resonance?

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

21. - E5B09

What is the relationship between the current through a capacitor and the voltage across a capacitor?

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

22. - E5C07

What is a vector?

Select	Answer
A	The inverse of the tangent function
B	The value of a quantity that changes over time
C	A quantity with both magnitude and an angular component
D	The inverse of the sine function

23. - E5D14

What is reactive power?

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

24. - E6A06

What is the beta of a bipolar junction transistor?

Select	Answer
A	The switching speed of the transistor
B	The breakdown voltage of the base to collector junction
C	The frequency at which the current gain is reduced to 1
D	The change in collector current with respect to base current

25. - E6B05

What characteristic of a PIN diode makes it useful as an RF switch or attenuator?

Select	Answer
A	Extremely high reverse breakdown voltage
B	Reverse bias controls its forward voltage drop
C	A large region of intrinsic material
D	Ability to dissipate large amounts of power

26. - E6C12

What is BiCMOS logic?

Select	Answer
A	A FET logic family based on bimetallic semiconductors
B	A logic family based on bismuth CMOS devices
C	A logic device with two CMOS circuits per package
D	An integrated circuit logic family using both bipolar and CMOS transistors

27. - E6D07

What is the usable frequency range of inductors that use toroidal cores, assuming a correct selection of core material for the frequency being used?

Select	Answer
A	From less than 20 Hz to approximately 300 MHz
B	From approximately 10 Hz to no more than 3000 kHz
C	From a few kHz to no more than 30 MHz
D	From about 100 kHz to at least 1000 GHz

28. - E6E12

Why are high-power RF amplifier ICs and transistors sometimes mounted in ceramic packages?

Select	Answer
A	Better dissipation of heat
B	To provide a low-pass frequency response
C	High-voltage insulating ability
D	Enhanced sensitivity to light

29. - 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

30. - E7A06

What is a characteristic of a monostable multivibrator?

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

31. - E7B08

How can an RF power amplifier be neutralized?

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

32. - E7C11

Which of the following is the common name for a filter network which is equivalent to two L-networks connected back-to-back with the two inductors in series and the capacitors in shunt at the input and output?

Select	Answer
A	Cascode
B	Pi
C	Pi-L
D	Omega

33. - E7D05

Which of the following types of linear voltage regulator places a constant load on the unregulated voltage source?

Select	Answer
A	A series regulator
B	A shunt regulator
C	A shunt current source
D	A constant current source

34. - 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

35. - E7F07

What function can a Fast Fourier Transform perform?

Select	Answer
A	Converting digital signals from the time domain to the frequency domain
B	Converting 8-bit data to 16 bit data
C	Converting analog signals to digital form
D	Converting digital signals to analog form

36. - E7G02

What is the effect of ringing in a filter?

Select	Answer
A	A reduction in high frequency response
B	Undesired oscillations added to the desired signal
C	An echo caused by a long time delay
D	Partial cancellation of the signal over a range of frequencies

37. - E7H08

Which of the following components can be used to reduce thermal drift in crystal oscillators?

Select	Answer
A	NP0 capacitors
B	Non-inductive resistors
C	Toroidal inductors
D	Wirewound resistors

38. - E8A11

What type of information can be conveyed using digital waveforms?

Select	Answer
A	Data
B	Video signals
C	Human speech
D	All of these choices are correct

39. - 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	2000
B	3
C	1/3
D	6000

40. - E8C04

What technique is used to minimize the bandwidth requirements of a PSK31 signal?

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

41. - E8D01

Why are received spread spectrum signals resistant to interference?

Select	Answer
A	The high power used by a spread spectrum transmitter keeps its signal from being easily overpowered
B	If interference is detected by the receiver it will signal the transmitter to change frequencies
C	The receiver is always equipped with a digital blanker
D	Signals not using the spread spectrum algorithm are suppressed in the receiver

42. - E9A05

What is included in the total resistance of an antenna system?

Select	Answer
A	Transmission-line resistance plus radiation resistance
B	Radiation resistance plus space impedance
C	Radiation resistance plus ohmic resistance
D	Radiation resistance plus transmission resistance

43. - E9B09

What type of computer program technique is commonly used for modeling antennas?

Select	Answer
A	Method of Moments
B	Calculus differentiation with respect to physical properties
C	Graphical analysis
D	Mutual impedance analysis

44. - E9C12

Which of the following describes an extended double Zepp antenna?

Select	Answer
A	A wideband vertical antenna constructed from precisely tapered aluminum tubing
B	A center fed 1.25 wavelength antenna (two 5/8 wave elements in phase)
C	An end fed folded dipole antenna
D	A portable antenna erected using two push support poles

45. - E9D07

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

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

46. - E9E11

What is an effective way of matching a feed line to a VHF or UHF antenna when the impedances of both the antenna and feed line are unknown?

Select	Answer
A	Use a 50 ohm 1:1 balun between the antenna and feed line
B	Connect a parallel-resonant LC network across the antenna feed terminals
C	Use the universal stub matching technique
D	Connect a series-resonant LC network across the antenna feed terminals

47. - E9F01

What is the velocity factor of a transmission line?

Select	Answer
A	The velocity of the wave in the transmission line divided by the velocity of light in a vacuum
B	The ratio of the characteristic impedance of the line to the terminating impedance
C	The index of shielding for coaxial cable
D	The velocity of the wave in the transmission line multiplied by the velocity of light in a vacuum

48. - 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	Reactance axis
B	Prime axis
C	Polar axis
D	Impedance axis

49. - E9H02

Which is generally true for low band (160 meter and 80 meter) receiving antennas?

Select	Answer
A	All of these choices are correct
B	Atmospheric noise is so high that gain over a dipole is not important
C	Low loss coax transmission line is essential for good performance
D	They must be erected at least 1/2 wavelength above the ground to attain good directivity

50. - 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	Each transmitter that produces 5 percent or more of its MPE limit at accessible locations
B	Only the most powerful transmitter
C	Only commercial transmitters
D	Each transmitter operating with a duty-cycle greater than 50 percent

Figure E9-3