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	Yes, because you were not the station calling CQ
C	No, U.S. stations are not permitted to use phone emissions above 14.340 MHz
D	Yes, because the displayed frequency is within the 20 meter band

2. - E1B01

Which of the following constitutes a spurious emission?

Select	Answer
A	Any transmitted signal that unintentionally interferes with another licensed radio station
B	An emission outside its necessary bandwidth that can be reduced or eliminated without affecting the information transmitted
C	An amateur station transmission made at random without the proper call sign identification
D	A signal transmitted to prevent its detection by any station other than the intended recipient

3. - E1C03

How do the control operator responsibilities of a station under automatic control differ from one under local control?

Select	Answer
A	Under automatic control there is no control operator
B	Under local control there is no control operator
C	Under local control a control operator is not required to be present at a control point
D	Under automatic control the control operator is not required to be present at the control point

4. - E1D08

Which VHF amateur service bands have frequencies available for space stations?

Select	Answer
A	2 meters and 1.25 meters
B	6 meters and 2 meters
C	6 meters, 2 meters, and 1.25 meters
D	2 meters

5. - E1E01

What is the minimum number of qualified VEs required to administer an Element 4 amateur operator license examination?

Select	Answer
A	3
B	4
C	5
D	2

6. - E1F07

When may an amateur station send a message to a business?

Select	Answer
A	When the control operator is employed by the FCC or another government agency
B	When the total money involved does not exceed $25
C	When neither the amateur nor his or her employer has a pecuniary interest in the communications
D	When transmitting international third-party communications

7. - E2A11

What type of antenna can be used to minimize the effects of spin modulation and Faraday rotation?

Select	Answer
A	An isotropic antenna
B	A circularly polarized antenna
C	A log-periodic dipole array
D	A linearly polarized antenna

8. - E2B19

What special operating frequency restrictions are imposed on slow scan TV transmissions?

Select	Answer
A	They are restricted to phone band segments and their bandwidth can be no greater than that of a voice signal of the same modulation type
B	None; they are allowed on all amateur frequencies
C	They are not permitted above 54 MHz
D	They are restricted to 7.245 MHz, 14.245 MHz, 21.345 MHz, and 28.945 MHz

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

10. - E2D03

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

Select	Answer
A	PACTOR III
B	FSK441
C	JT65
D	Olivia

11. - E2E10

Which of these digital modes has the narrowest bandwidth?

Select	Answer
A	MFSK16
B	170 Hz shift, 45 baud RTTY
C	PSK31
D	300-baud packet

12. - E3A02

What characterizes libration fading of an EME signal?

Select	Answer
A	A fluttery irregular fading
B	The returning echo is several Hertz lower in frequency than the transmitted signal
C	A slow change in the pitch of the CW signal
D	A gradual loss of signal as the Sun rises

13. - E3B12

What is the primary characteristic of chordal hop propagation?

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

14. - E3C07

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

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

15. - E4A08

Which of the following instrument would be best for measuring the SWR of a beam antenna?

Select	Answer
A	An ohmmeter
B	A spectrum analyzer
C	A Q meter
D	An antenna analyzer

16. - E4B13

Which S parameter is equivalent to forward gain?

Select	Answer
A	S11
B	S21
C	S22
D	S12

17. - E4C06

A CW receiver with the AGC off has an equivalent input noise power density of -174 dBm/Hz. What would be the level of an unmodulated carrier input to this receiver that would yield an audio output SNR of 0 dB in a 400 Hz noise bandwidth?

Select	Answer
A	-155 dBm
B	-164 dBm
C	-174 dBm
D	-148 dBm

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

19. - E4E06

What is a major cause of atmospheric static?

Select	Answer
A	Thunderstorms
B	Meteor showers
C	Geomagnetic storms
D	Solar radio frequency emissions

20. - E5A01

What can cause the voltage across reactances in series to be larger than the voltage applied to them?

Select	Answer
A	Resonance
B	Resistance
C	Capacitance
D	Conductance

21. - E5B03

What happens to the phase angle of a reactance when it is converted to a susceptance?

Select	Answer
A	It is unchanged
B	It is shifted by 90 degrees
C	The sign is reversed
D	The susceptance phase angle is the inverse of the reactance phase angle

22. - E5C01

Which of the following represents a capacitive reactance in rectangular notation?

Select	Answer
A	+jX
B	Omega
C	X
D	-jX

23. - E5D14

What is reactive power?

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

24. - E6A07

Which of the following indicates that a silicon NPN junction transistor is biased on?

Select	Answer
A	Base-to-emitter voltage of approximately 6 to 7 volts
B	Base-to-emitter resistance of approximately 0.6 to 0.7 ohms
C	Base-to-emitter voltage of approximately 0.6 to 0.7 volts
D	Base-to-emitter resistance of approximately 6 to 7 ohms

25. - E6B11

What is used to control the attenuation of RF signals by a PIN diode?

Select	Answer
A	Capacitance of an RF coupling capacitor
B	A sub-harmonic pump signal
C	Forward DC bias current
D	Reverse voltage larger than the RF signal

26. - E6C08

In Figure E6-5, what is the schematic symbol for a NAND gate?

Select	Answer
A	4
B	3
C	2
D	1

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

28. - E6E01

Which of the following is true of a charge-coupled device (CCD)?

Select	Answer
A	It samples an analog signal and passes it in stages from the input to the output
B	It is a CMOS analog-to-digital converter
C	Its phase shift changes rapidly with frequency
D	It is used in a battery charger circuit

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 that uses a glowing liquid to remain brightly lit in dim light
D	A display utilizing a crystalline liquid and polarizing filters which becomes opaque when voltage is applied

30. - E7A04

How many flip-flops are required to divide a signal frequency by 4?

Select	Answer
A	8
B	2
C	1
D	4

31. - E7B18

What is a characteristic of a grounded-grid amplifier?

Select	Answer
A	Low bandwidth
B	High power gain
C	High filament voltage
D	Low input impedance

32. - E7C02

Which of the following is a property of a T-network with series capacitors and a parallel shunt inductor?

Select	Answer
A	It is a notch filter
B	It is a band-pass filter
C	It is a high-pass filter
D	It is a low-pass filter

33. - E7D09

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

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

34. - E7E03

How does an analog phase modulator function?

Select	Answer
A	By varying the tuning of a microphone preamplifier to produce AM signals
B	By varying the tuning of a microphone preamplifier to produce PM signals
C	By varying the tuning of an amplifier tank circuit to produce PM signals
D	By varying the tuning of an amplifier tank circuit to produce AM signals

35. - E7F12

What digital process is applied to I and Q signals in order to recover the baseband modulation information?

Select	Answer
A	Decimation
B	Fast Fourier Transform
C	Signal conditioning
D	Quadrature mixing

36. - E7G01

What is the typical output impedance of an integrated circuit op-amp?

Select	Answer
A	1000 ohms
B	100 ohms
C	Very high
D	Very low

37. - E7H10

What information is contained in the lookup table of a direct digital frequency synthesizer?

Select	Answer
A	The phase relationship between a voltage-controlled oscillator and the output waveform
B	The amplitude values that represent a sine-wave output
C	The phase relationship between a reference oscillator and the output waveform
D	The synthesizer frequency limits and frequency values stored in the radio memories

38. - E8A04

What is "dither" with respect to analog to digital converters?

Select	Answer
A	An abnormal condition where the converter cannot settle on a value to represent the signal
B	A method of decimation by randomly skipping samples
C	A small amount of noise added to the input signal to allow more precise representation of a signal over time
D	An error caused by irregular quantization step size

39. - E8B08

What describes Orthogonal Frequency Division Multiplexing?

Select	Answer
A	A bandwidth compression technique using Fourier transforms
B	A digital mode for narrow band, slow speed transmissions
C	A digital modulation technique using subcarriers at frequencies chosen to avoid intersymbol interference
D	A frequency modulation technique which uses non-harmonically related frequencies

40. - E8C11

What is the relationship between symbol rate and baud?

Select	Answer
A	They are the same
B	Baud is only used for RTTY
C	Baud is twice the symbol rate
D	Symbol rate is only used for packet-based modes

41. - E8D11

What is one advantage of using ASCII code for data communications?

Select	Answer
A	It is possible to transmit both upper and lower case text
B	It uses one character as a shift code to send numeric and special characters
C	It includes built in error correction features
D	It contains fewer information bits per character than any other code

42. - E9A07

What is meant by antenna gain?

Select	Answer
A	The ratio of the amount of power radiated by an antenna compared to the transmitter output power
B	The final amplifier gain minus the transmission line losses
C	The ratio of the radiated signal strength of an antenna in the direction of maximum radiation to that of a reference antenna
D	The ratio of the signal in the forward direction to that in the opposite direction

43. - E9B13

What does the abbreviation NEC stand for when applied to antenna modeling programs?

Select	Answer
A	National Electrical Code
B	Numerical Electromagnetic Code
C	Numeric Electrical Computation
D	Next Element Comparison

44. - E9C14

How does the performance of a horizontally polarized antenna mounted on the side of a hill compare with the same antenna mounted on flat ground?

Select	Answer
A	The horizontal beam width decreases in the downhill direction
B	The main lobe takeoff angle decreases in the downhill direction
C	The horizontal beam width increases in the uphill direction
D	The main lobe takeoff angle increases in the downhill direction

45. - E9D01

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

Select	Answer
A	Gain does not change
B	Gain is multiplied by 0.707
C	Gain increases by 6 dB
D	Gain increases by 3 dB

46. - E9E06

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

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

47. - E9F14

What impedance does a 1/2 wavelength transmission line present to a generator when the line is shorted at the far end?

Select	Answer
A	The same as the output impedance of the generator
B	Very low impedance
C	The same as the characteristic impedance of the line
D	Very high impedance

48. - E9G10

What do the arcs on a Smith chart represent?

Select	Answer
A	Points with constant reactance
B	Points with constant resistance
C	Frequency
D	SWR

49. - E9H01

When constructing a Beverage antenna, which of the following factors should be included in the design to achieve good performance at the desired frequency?

Select	Answer
A	It should be one or more wavelengths long
B	It should be configured as a four-sided loop
C	Its overall length must not exceed 1/4 wavelength
D	It must be mounted more than 1 wavelength above ground

50. - E0A06

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

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

Figure E6-5