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

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1. - E1A14

What is the maximum bandwidth for a data emission on 60 meters?

Select	Answer
A	170 Hz
B	60 Hz
C	1.5 kHz
D	2.8 kHz

2. - E1B07

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	0.5
C	1.0
D	2.0

3. - E1C11

Which of the following operating arrangements allows an FCC-licensed U.S. citizen to operate in many European countries, and alien amateurs from many European countries to operate in the U.S.?

Select	Answer
A	All of these choices are correct
B	IARP agreement
C	ITU reciprocal license
D	CEPT agreement

4. - E1D11

Which amateur stations are eligible to operate as Earth stations?

Select	Answer
A	Any amateur station, subject to the privileges of the class of operator license held by the control operator
B	Any amateur station whose licensee has filed a pre-space notification with the FCC's International Bureau
C	Only those of Amateur Extra Class operators
D	Only those of General, Advanced or Amateur Extra Class operators

5. - E1E05

What is the minimum passing score on amateur operator license examinations?

Select	Answer
A	Minimum passing score of 70%
B	Minimum passing score of 77%
C	Minimum passing score of 80%
D	Minimum passing score of 74%

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

7. - E2A01

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

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

8. - E2B15

What signals SSTV receiving equipment to begin a new picture line?

Select	Answer
A	Specific tone frequencies
B	Elapsed time
C	Specific tone amplitudes
D	A two-tone signal

9. - E2C04

What type of transmission is most often used for a ham radio mesh network?

Select	Answer
A	Spread spectrum in the 2.4 GHz band
B	Store and forward on the 440 MHz band
C	Frequency division multiplex in the 24 GHz band
D	Multiple Frequency Shift Keying in the 10 GHz band

10. - E2D10

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

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

11. - E2E09

Which of the following HF digital modes uses variable-length coding for bandwidth efficiency?

Select	Answer
A	PSK31
B	PACTOR
C	MT63
D	RTTY

12. - E3A01

What is the approximate maximum separation measured along the surface of the Earth between two stations communicating by Moon bounce?

Select	Answer
A	5000 miles, if the Moon is at perigee
B	500 miles, if the Moon is at perigee
C	2000 miles, if the Moon is at apogee
D	12,000 miles, if the Moon is visible by both stations

13. - E3B09

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

Select	Answer
A	Around the equinoxes, especially the fall equinox
B	Around the solstices, especially the winter solstice
C	Around the equinoxes, especially the spring equinox
D	Around the solstices, especially the summer solstice

14. - E3C15

What might a sudden rise in radio background noise indicate?

Select	Answer
A	Long-path propagation is occurring
B	A solar flare has occurred
C	Increased transequatorial propagation likely
D	A meteor ping

15. - E4A03

Which of the following test instrument is used to display spurious signals and/or intermodulation distortion products in an SSB transmitter?

Select	Answer
A	A spectrum analyzer
B	A wattmeter
C	A time-domain reflectometer
D	A logic analyzer

16. - E4B11

How should an antenna analyzer be connected when measuring antenna resonance and feed point impedance?

Select	Answer
A	Connect the analyzer via a high-impedance transformer to the antenna
B	Loosely couple the analyzer near the antenna base
C	Connect the antenna feed line directly to the analyzer's connector
D	Loosely couple the antenna and a dummy load to the analyzer

17. - E4C12

What is an undesirable effect of using too wide a filter bandwidth in the IF section of a receiver?

Select	Answer
A	Undesired signals may be heard
B	Thermal-noise distortion
C	Filter ringing
D	Output-offset overshoot

18. - E4D10

What does a third-order intercept level of 40 dBm mean with respect to receiver performance?

Select	Answer
A	A pair of 1 mW input signals will produce a third-order intermodulation product which is 40 dB stronger than the input signal
B	Signals less than 40 dBm will not generate audible third-order intermodulation products
C	The receiver can tolerate signals up to 40 dB above the noise floor without producing third-order intermodulation products
D	A pair of 40 dBm signals will theoretically generate a third-order intermodulation product with the same level as the input signals

19. - E4E04

How can conducted and radiated noise caused by an automobile alternator be suppressed?

Select	Answer
A	By installing filter capacitors in series with the DC power lead and a blocking capacitor in the field lead
B	By installing a noise suppression resistor and a blocking capacitor in both leads
C	By installing a high-pass filter in series with the radio's power lead and a low-pass filter in parallel with the field lead
D	By connecting the radio's power leads directly to the battery and by installing coaxial capacitors in line with the alternator leads

20. - E5A01

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

Select	Answer
A	Conductance
B	Resonance
C	Capacitance
D	Resistance

21. - E5B06

What is susceptance?

Select	Answer
A	The inverse of reactance
B	The magnetic impedance of a circuit
C	The ratio of magnetic field to electric field
D	A measure of the efficiency of a transformer

22. - E5C06

What does the impedance 50-j25 represent?

Select	Answer
A	25 ohms resistance in series with 50 ohms capacitive reactance
B	50 ohms resistance in series with 25 ohms capacitive reactance
C	25 ohms resistance in series with 50 ohms inductive reactance
D	50 ohms resistance in series with 25 ohms inductive reactance

23. - E5D04

Why are short connections necessary at microwave frequencies?

Select	Answer
A	To reduce noise figure
B	Because of ground reflections
C	To increase neutralizing resistance
D	To reduce phase shift along the connection

24. - E6A10

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

Select	Answer
A	4
B	6
C	5
D	2

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	Ability to dissipate large amounts of power
C	A large region of intrinsic material
D	Reverse bias controls its forward voltage drop

26. - E6C09

What is a Programmable Logic Device (PLD)?

Select	Answer
A	An algorithm for simulating logic functions during circuit design
B	Programmable equipment used for testing digital logic integrated circuits
C	A programmable collection of logic gates and circuits in a single integrated circuit
D	A device to control industrial equipment

27. - E6D13

What is the primary cause of inductor self-resonance?

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

28. - E6E02

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

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

29. - E6F02

What happens to the conductivity of a photoconductive material when light shines on it?

Select	Answer
A	It increases
B	It decreases
C	It stays the same
D	It becomes unstable

30. - E7A08

What logical operation does an OR gate perform?

Select	Answer
A	It produces logic "1" at its output if any or all inputs are logic "1"
B	It produces logic "1" at its output if all inputs are logic "0"
C	It only produces logic "0" at its output when all inputs are logic "1"
D	It produces logic "0" at its output if all inputs are logic "1"

31. - E7B01

For what portion of a signal cycle does a Class AB amplifier operate?

Select	Answer
A	Exactly 180 degrees
B	More than 180 degrees but less than 360 degrees
C	The entire cycle
D	Less than 180 degrees

32. - E7C15

What is a crystal lattice filter?

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

33. - E7D07

What is the purpose of C2 in the circuit shown in Figure E7-3?

Select	Answer
A	To provide fixed DC bias for Q1
B	It is a brute force filter for the output
C	To self-resonate at the hum frequency
D	It bypasses hum around D1

34. - E7E04

What is one way a single-sideband phone signal can be generated?

Select	Answer
A	By driving a product detector with a DSB signal
B	By using a loop modulator followed by a mixer
C	By using a balanced modulator followed by a filter
D	By using a reactance modulator followed by a mixer

35. - E7F02

What kind of digital signal processing audio filter is used to remove unwanted noise from a received SSB signal?

Select	Answer
A	A phase-inverting filter
B	A Hilbert-transform filter
C	A crystal-lattice filter
D	An adaptive filter

36. - E7G05

How can unwanted ringing and audio instability be prevented in a multi-section op-amp RC audio filter circuit?

Select	Answer
A	Restrict Q but increase gain
B	Increase both gain and Q
C	Restrict both gain and Q
D	Restrict gain but increase Q

37. - E7H15

Which of these functions can be performed by a phase-locked loop?

Select	Answer
A	Comparison of two digital input signals, digital pulse counter
B	Frequency synthesis, FM demodulation
C	Photovoltaic conversion, optical coupling
D	Wide-band AF and RF power amplification

38. - E8A12

What is an advantage of using digital signals instead of analog signals to convey the same information?

Select	Answer
A	Digital signals always occupy a narrower bandwidth
B	All of these choices are correct
C	Less complex circuitry is required for digital signal generation and detection
D	Digital signals can be regenerated multiple times without error

39. - E8B11

What is digital time division multiplexing?

Select	Answer
A	Two or more data streams share the same channel by transmitting time of transmission as the sub-carrier
B	Two or more data streams are assigned to discrete sub-carriers on an FM transmitter
C	Two or more signals are quadrature modulated to increase bandwidth efficiency
D	Two or more signals are arranged to share discrete time slots of a data transmission

40. - E8C09

Which is the name of a digital code where each preceding or following character changes by only one bit?

Select	Answer
A	Binary Coded Decimal Code
B	Gray code
C	Excess 3 code
D	Extended Binary Coded Decimal Interchange Code

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	High reflected power
C	Strong ALC action
D	Harmonics on higher bands

42. - E9A13

How much gain does an antenna have compared to a 1/2-wavelength dipole when it has 12 dB gain over an isotropic antenna?

Select	Answer
A	9.85 dB
B	12.5 dB
C	6.17 dB
D	14.15 dB

43. - E9B14

What type of information can be obtained by submitting the details of a proposed new antenna to a modeling program?

Select	Answer
A	Polar plots of the far field elevation and azimuth patterns
B	Antenna gain
C	All of these choices are correct
D	SWR vs frequency charts

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

45. - E9D09

What is the function of a loading coil used as part of an HF mobile antenna?

Select	Answer
A	To lower the Q
B	To cancel capacitive reactance
C	To increase the SWR bandwidth
D	To lower the losses

46. - E9E13

What is a use for a Wilkinson divider?

Select	Answer
A	It is used to feed high-impedance antennas from a low-impedance source
B	It is used to divide power equally between two 50 ohm loads while maintaining 50 ohm input impedance
C	It is used to feed low-impedance loads from a high-impedance source
D	It divides the operating frequency of a transmitter signal so it can be used on a lower frequency band

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

48. - E9G07

On the Smith chart shown in Figure E9-3, what is the only straight line shown?

Select	Answer
A	The resistance axis
B	The current axis
C	The reactance axis
D	The voltage axis

49. - E9H08

What is the function of a sense antenna?

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

50. - E0A07

How may dangerous levels of carbon monoxide from an emergency generator be detected?

Select	Answer
A	By the odor
B	By the yellowish appearance of the gas
C	Only with a carbon monoxide detector
D	Any ordinary smoke detector can be used

Figure E6-2

Figure E7-3

Figure E9-3