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

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1. - 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	Only commercial transmitters
B	Only the most powerful transmitter
C	Each transmitter operating with a duty cycle greater than 50 percent
D	Each transmitter that produces 5 percent or more of its MPE limit in areas where the total MPE limit is exceeded.

2. - E1A01

Which of the following carrier frequencies is illegal for LSB AFSK emissions on the 17 meter band RTTY and data segment of 18.068 to 18.110 MHz?

Select	Answer
A	18.107 MHz
B	18.068 MHz
C	18.110 MHz
D	18.100 MHz

3. - E1B05

What is the National Radio Quiet Zone?

Select	Answer
A	An area in Puerto Rico surrounding the Arecibo Radio Telescope
B	An area surrounding the National Radio Astronomy Observatory
C	An area in Florida surrounding Cape Canaveral
D	An area in New Mexico surrounding the White Sands Test Area

4. - E1C09

What is the highest modulation index permitted at the highest modulation frequency for angle modulation below 29.0 MHz?

Select	Answer
A	3.0
B	2.0
C	1.0
D	0.5

5. - E1D12

Which of the following amateur stations may transmit one-way communications?

Select	Answer
A	A local repeater or linked repeater station
B	A space station, beacon station, or telecommand station
C	A message forwarding station or automatically controlled digital station
D	All these choices are correct

6. - E1E03

What is a Volunteer Examiner Coordinator?

Select	Answer
A	A person who has volunteered to prepare amateur operator license examinations
B	An organization that has entered into an agreement with the FCC to coordinate, prepare, and administer amateur operator license examinations
C	The person who has entered into an agreement with the FCC to be the VE session manager
D	A person who has volunteered to administer amateur operator license examinations

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

8. - E2A01

What is the direction of an ascending pass for an amateur satellite?

Select	Answer
A	From south to north
B	From north to south
C	From east to west
D	From west to east

9. - E2B08

What technique allows commercial analog TV receivers to be used for fast-scan TV operations on the 70 cm band?

Select	Answer
A	Using converted satellite TV dishes
B	Transmitting on channels shared with cable TV
C	Using USB and demodulating the signal with a computer sound card
D	Transmitting on the abandoned TV channel 2

10. - E2C08

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

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

11. - E2D03

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

Select	Answer
A	MSK144
B	JT65
C	Olivia
D	PACTOR III

12. - E2E11

What is the difference between direct FSK and audio FSK?

Select	Answer
A	Only direct FSK can be decoded by computer
B	Direct FSK can transmit faster baud rates
C	Direct FSK applies the data signal to the transmitter VFO, while AFSK transmits tones via phone
D	Direct FSK occupies less bandwidth

13. - E3A10

Which type of atmospheric structure can create a path for microwave propagation?

Select	Answer
A	Temperature inversion
B	Wind shear
C	The jet stream
D	Dust devil

14. - E3B03

What is the best time of day for transequatorial propagation?

Select	Answer
A	Late at night
B	Morning
C	Afternoon or early evening
D	Noon

15. - E3C05

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

Select	Answer
A	Westward
B	Eastward
C	Northward
D	Southward

16. - E4A08

Which of the following measures SWR?

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

17. - E4B07

What do the subscripts of S parameters represent?

Select	Answer
A	Relative quality of the data
B	Frequency order of the measurements
C	The port or ports at which measurements are made
D	The relative time between measurements

18. - 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	-174 dBm
C	-164 dBm
D	-148 dBm

19. - E4D07

Which of the following reduces the likelihood of receiver desensitization?

Select	Answer
A	Raise the receiver IF frequency
B	Decrease the RF bandwidth of the receiver
C	Switch from fast AGC to slow AGC
D	Increase the receiver front end gain

20. - E4E11

What could cause local AM broadcast band signals to combine to generate spurious signals in the MF or HF bands?

Select	Answer
A	One or more of the broadcast stations is transmitting an over-modulated signal
B	Nearby corroded metal joints are mixing and re-radiating the broadcast signals
C	Your station receiver IF amplifier stage is defective
D	You are receiving skywave signals from a distant station

21. - E5A11

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

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

22. - E5B01

What is the term for the time required for the capacitor in an RC circuit to be charged to 63.2% of the applied voltage or to discharge to 36.8% of its initial voltage?

Select	Answer
A	An exponential rate of one
B	One time constant
C	A time factor of one
D	One exponential period

23. - E5C05

What is the name of the diagram used to show the phase relationship between impedances at a given frequency?

Select	Answer
A	Phasor diagram
B	Far field diagram
C	Venn diagram
D	Near field diagram

24. - E5D01

What is the result of skin effect?

Select	Answer
A	Thermal effects on the surface of the conductor decrease the impedance
B	Thermal effects on the surface of the conductor increase the impedance
C	As frequency increases, RF current flows in a thinner layer of the conductor, closer to the surface
D	As frequency decreases, RF current flows in a thinner layer of the conductor, closer to the surface

25. - E6A02

Which of the following semiconductor materials contains excess free electrons?

Select	Answer
A	Bipolar
B	P-type
C	Insulated gate
D	N-type

26. - E6B11

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

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

27. - E6C05

What is an advantage of CMOS logic devices over TTL devices?

Select	Answer
A	Differential output capability
B	Lower distortion
C	Lower power consumption
D	Immune to damage from static discharge

28. - E6D06

What core material property determines the inductance of an inductor?

Select	Answer
A	Permeability
B	Thermal impedance
C	Reactivity
D	Resistance

29. - E6E07

What type of transmission line is used for connections to MMICs?

Select	Answer
A	Miniature coax
B	Microstrip
C	Parallel wire
D	Circular waveguide

30. - E6F01

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

Select	Answer
A	Photons
B	Protons
C	Holes
D	Electrons

31. - E7A02

What is the function of a decade counter?

Select	Answer
A	It decodes a binary number for display on a seven-segment LED display
B	It produces one output pulse for every 10 input pulses
C	It produces 10 output pulses for every input pulse
D	It decodes a decimal number for display on a seven-segment LED display

32. - E7B06

Which of the following amplifier types reduces even-order harmonics?

Select	Answer
A	Push-push
B	Class C
C	Class AB
D	Push-pull

33. - E7C10

Which of the following filters would be the best choice for use in a 2 meter band repeater duplexer?

Select	Answer
A	A cavity filter
B	An L-C filter
C	A DSP filter
D	A crystal filter

34. - E7D04

Which of the following types of linear voltage regulator usually make the most efficient use of the primary power source?

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

35. - E7E09

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

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

36. - E7F10

What aspect of receiver analog-to-digital conversion determines the maximum receive bandwidth of a Direct Digital Conversion SDR?

Select	Answer
A	Sample clock phase noise
B	Sample width in bits
C	Sample rate
D	Processor latency

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	94
B	47
C	0.21
D	24

38. - E7H03

How is positive feedback supplied in a Hartley oscillator?

Select	Answer
A	Through a tapped coil
B	Through a neutralizing capacitor
C	Through a capacitive divider
D	Through link coupling

39. - E8A01

What is the name of the process that shows that a square wave is made up of a sine wave plus all its odd harmonics?

Select	Answer
A	Vector analysis
B	Numerical analysis
C	Differential analysis
D	Fourier analysis

40. - E8B08

What describes Orthogonal Frequency Division Multiplexing?

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

41. - E8C07

What is the bandwidth of a 4800-Hz frequency shift, 9600-baud ASCII FM transmission?

Select	Answer
A	15.36 kHz
B	5.76 kHz
C	4.8 kHz
D	9.6 kHz

42. - E8D06

What is the advantage of including parity bits in ASCII characters?

Select	Answer
A	Some types of errors can be detected
B	Foreign language characters can be sent
C	The signal can overpower interfering signals
D	Faster transmission rate

43. - E9A03

What is the radiation resistance of an antenna?

Select	Answer
A	The specific impedance of the antenna
B	The value of a resistance that would dissipate the same amount of power as that radiated from an antenna
C	The resistance in the atmosphere that an antenna must overcome to be able to radiate a signal
D	The combined losses of the antenna elements and feed line

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	18 dB
C	24 dB
D	12 dB

45. - E9C06

What is the effect of adding a terminating resistor to a rhombic antenna?

Select	Answer
A	It reflects the standing waves on the antenna elements back to the transmitter
B	It changes the radiation pattern from horizontal to vertical polarization
C	It decreases the ground loss
D	It changes the radiation pattern from bidirectional to unidirectional

46. - E9D02

How can linearly polarized Yagi antennas be used to produce circular polarization?

Select	Answer
A	Arrange two Yagis perpendicular to each other with the driven elements at the same point on the boom fed 90 degrees out of phase
B	Stack two Yagis fed in phase to form an array with the respective elements in parallel planes
C	Arrange two Yagis collinear to each other with the driven elements fed 180 degrees out of phase
D	Stack two Yagis fed 90 degrees out of phase to form an array with the respective elements in parallel planes

47. - E9E07

What parameter describes the interactions at the load end of a mismatched transmission line?

Select	Answer
A	Reflection coefficient
B	Characteristic impedance
C	Velocity factor
D	Dielectric constant

48. - E9F10

What impedance does a 1/8-wavelength transmission line present to a generator when the line is shorted at the far end?

Select	Answer
A	An inductive reactance
B	A capacitive reactance
C	The same as the characteristic impedance of the line
D	Zero

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. - E9H08

What is the function of a sense antenna?

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

Figure E9-1