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

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1. - E1A12

With your transceiver displaying the carrier frequency of CW signals, you hear a DX station's CQ on 3.500 MHz. Is it legal to return the call using CW on the same frequency?

Select	Answer
A	Yes, the displayed frequency is within the 80 meter CW band segment
B	No, U.S. stations are not permitted to use CW emissions below 3.525 MHz
C	No, one of the sidebands of the CW signal will be out of the band
D	Yes, the DX station initiated the contact

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

3. - E1C06

Which of the following statements concerning remotely controlled amateur stations is true?

Select	Answer
A	Repeater and auxiliary stations may not be remotely controlled
B	A control operator must be present at the control point
C	A control operator need not be present at the control point
D	Only Extra Class operators may be the control operator of a remote station

4. - E1D04

What is an Earth station in the amateur satellite service?

Select	Answer
A	An amateur station within 50 km of the Earth's surface intended for communications with amateur stations by means of objects in space
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 that is not able to communicate using amateur satellites

5. - E1E01

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

Select	Answer
A	2
B	5
C	4
D	3

6. - E1F03

Under what circumstances may a dealer sell an external RF power amplifier capable of operation below 144 MHz if it has not been granted FCC certification?

Select	Answer
A	It was imported from a manufacturer in another country and was certificated by that country's government
B	The equipment dealer assembled it from a kit
C	It was purchased in used condition from an amateur operator and is sold to another amateur operator for use at that operator's station
D	It was imported from a manufacturer in a country that does not require certification of RF power amplifiers

7. - E2A05

What do the letters in a satellite's mode designator specify?

Select	Answer
A	The location of the ground control station
B	Power limits for uplink and downlink transmissions
C	The polarization of uplink and downlink signals
D	The uplink and downlink frequency ranges

8. - E2B14

What aspect of an amateur slow-scan television signal encodes the brightness of the picture?

Select	Answer
A	Sync frequency
B	Tone amplitude
C	Sync amplitude
D	Tone frequency

9. - E2C13

What indicator is required to be used by U.S.-licensed operators when operating a station via remote control where the transmitter is located in the U.S.?

Select	Answer
A	No additional indicator is required
B	/ followed by the USPS two letter abbreviation for the state in which the remote station is located
C	/R# where # is the district of the remote station
D	The ARRL section of the remote station

10. - E2D10

How can an APRS station be used to help support a public service communications activity?

Select	Answer
A	An APRS station with an emergency medical technician can automatically transmit medical data to the nearest hospital
B	All of these choices are correct
C	An APRS station with a GPS unit can automatically transmit information to show a mobile station's position during the event
D	APRS stations with General Personnel Scanners can automatically relay the participant numbers and time as they pass the check points

11. - E2E10

Which of these digital modes has the narrowest bandwidth?

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

12. - E3A17

What is meant by circularly polarized electromagnetic waves?

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

13. - E3B08

What type of HF propagation is probably occurring if radio signals travel along the terminator between daylight and darkness?

Select	Answer
A	Sporadic-E
B	Gray-line
C	Transequatorial
D	Long-path

14. - E3C09

How does the intensity of an X3 flare compare to that of an X2 flare?

Select	Answer
A	Four times as great
B	Twice as great
C	50 percent greater
D	10 percent greater

15. - E4A14

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

Select	Answer
A	It amplifies low level signals for more accurate counting
B	It divides a higher frequency signal so a low-frequency counter can display the input frequency
C	It multiplies a higher frequency signal so a low-frequency counter can display the operating frequency
D	It prevents oscillation in a low-frequency counter circuit

16. - E4B03

If a frequency counter with a specified accuracy of +/- 1.0 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 kHz
B	165.2 Hz
C	146.52 Hz
D	1.4652 MHz

17. - E4C08

An SDR receiver is overloaded when input signals exceed what level?

Select	Answer
A	The reference voltage of the analog-to-digital converter
B	One-half the maximum sampling buffer size
C	The maximum count value of the analog-to-digital converter
D	One-half the maximum sample rate

18. - E4D07

Which describes the most significant effect of an off-frequency signal when it is causing cross-modulation interference to a desired signal?

Select	Answer
A	A reduction in apparent signal strength
B	A large increase in background noise
C	The off-frequency unwanted signal is heard in addition to the desired signal
D	The desired signal can no longer be heard

19. - E4E03

Which of the following signals might a receiver noise blanker be able to remove from desired signals?

Select	Answer
A	Signals which appear across a wide bandwidth
B	Signals which appear at one IF but not another
C	Signals which are constant at all IF levels
D	Signals which have a sharply peaked frequency distribution

20. - E5A11

What is the half-power bandwidth of a parallel resonant circuit that has a resonant frequency of 7.1 MHz and a Q of 150?

Select	Answer
A	315.6 Hz
B	157.8 Hz
C	23.67 kHz
D	47.3 kHz

21. - E5B07

What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 500 ohms, R is 1 kilohm, and XL is 250 ohms?

Select	Answer
A	14.0 degrees with the voltage lagging the current
B	14.0 degrees with the voltage leading the current
C	68.2 degrees with the voltage leading the current
D	68.2 degrees with the voltage lagging the current

22. - E5C02

How are impedances described in polar coordinates?

Select	Answer
A	By X and R values
B	By phase angle and amplitude
C	By Y and G values
D	By real and imaginary parts

23. - E5D08

What type of energy is stored in an electromagnetic or electrostatic field?

Select	Answer
A	Thermodynamic energy
B	Kinetic energy
C	Potential energy
D	Electromechanical energy

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

25. - E6B09

What is a common use for point contact diodes?

Select	Answer
A	As an RF detector
B	As a high voltage rectifier
C	As a constant current source
D	As a constant voltage source

26. - E6C08

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

Select	Answer
A	1
B	4
C	2
D	3

27. - E6D06

What core material property determines the inductance of a toroidal inductor?

Select	Answer
A	Resistance
B	Thermal impedance
C	Reactivity
D	Permeability

28. - E6E06

What characteristics of the MMIC make it a popular choice for VHF through microwave circuits?

Select	Answer
A	Controlled gain, low noise figure, and constant input and output impedance over the specified frequency range
B	The ability to retrieve information from a single signal even in the presence of other strong signals
C	Plate current that is controlled by a control grid
D	Nearly infinite gain, very high input impedance, and very low output impedance

29. - E6F01

What is photoconductivity?

Select	Answer
A	The decreased conductivity of an illuminated semiconductor
B	The conversion of photon energy to electromotive energy
C	The conversion of electromotive energy to photon energy
D	The increased conductivity of an illuminated semiconductor

30. - E7A01

Which is a bi-stable circuit?

Select	Answer
A	An "OR" gate
B	A flip-flop
C	A clock
D	An "AND" gate

31. - E7B03

Which of the following components form the output of a class D amplifier circuit?

Select	Answer
A	A temperature compensating load resistor to improve linearity
B	A matched load resistor to prevent damage by switching transients
C	A low-pass filter to remove switching signal components
D	A high-pass filter to compensate for low gain at low frequencies

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	Pi-L
B	Cascode
C	Pi
D	Omega

33. - E7D01

What is one characteristic of a linear electronic voltage regulator?

Select	Answer
A	The control element duty cycle is proportional to the line or load conditions
B	It has a ramp voltage as its output
C	It eliminates the need for a pass transistor
D	The conduction of a control element is varied to maintain a constant output voltage

34. - E7E09

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

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

35. - E7F04

What is a common method of generating an SSB signal using digital signal processing?

Select	Answer
A	Combine signals with a quadrature phase relationship
B	A frequency synthesizer removes the unwanted sidebands
C	Mixing products are converted to voltages and subtracted by adder circuits
D	Emulation of quartz crystal filter characteristics

36. - E7G09

What will be the output voltage of the circuit shown in Figure E7-4 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	-2.3 volts
C	2.3 volts
D	0.23 volts

37. - E7H08

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

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

38. - E8A13

Which of these methods is commonly used to convert analog signals to digital signals?

Select	Answer
A	Harmonic regeneration
B	Sequential sampling
C	Level shifting
D	Phase reversal

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. - E8C01

How is Forward Error Correction implemented?

Select	Answer
A	By transmitting extra data that may be used to detect and correct transmission errors
B	By the receiving station repeating each block of three data characters
C	By varying the frequency shift of the transmitted signal according to a predefined algorithm
D	By transmitting a special algorithm to the receiving station along with the data characters

41. - E8D01

Why are received spread spectrum signals resistant to interference?

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

42. - E9A17

What is the effective radiated power of a repeater station with 200 watts transmitter power output, 2 dB feed line loss, 2.8 dB duplexer loss, 1.2 dB circulator loss, and 7 dBi antenna gain?

Select	Answer
A	159 watts
B	63.2 watts
C	632 watts
D	252 watts

43. - E9B11

What is a disadvantage of decreasing the number of wire segments in an antenna model below the guideline of 10 segments per half-wavelength?

Select	Answer
A	The resulting design will favor radiation of harmonic energy
B	The antenna will become mechanically unstable
C	Ground conductivity will not be accurately modeled
D	The computed feed point impedance may be incorrect

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

45. - E9D12

Which of the following would provide the best RF ground for your station?

Select	Answer
A	A 50 ohm resistor connected to ground
B	An electrically short connection to 3 or 4 interconnected ground rods driven into the Earth
C	An electrically short connection to a metal water pipe
D	An electrically short connection to 3 or 4 interconnected ground rods via a series RF choke

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. - E9F01

What is the velocity factor of a transmission line?

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

48. - 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 reactance values with regard to the resistance axis
C	Reassigning prime center with regard to the reactance axis
D	Reassigning resistance values with regard to the reactance axis

49. - E9H09

Which of the following describes the construction of a receiving loop antenna?

Select	Answer
A	A large circularly polarized antenna
B	A small coil of wire tightly wound around a toroidal ferrite core
C	One or more turns of wire wound in the shape of a large open coil
D	A vertical antenna coupled to a feed line through an inductive loop of wire

50. - E0A05

What is one of the potential hazards of using microwaves in the amateur radio bands?

Select	Answer
A	The extremely high frequency energy can damage the joints of antenna structures
B	Microwaves often travel long distances by ionospheric reflection
C	Microwaves are ionizing radiation
D	The high gain antennas commonly used can result in high exposure levels

Figure E6-5

Figure E7-4