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

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1. - E0A07

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

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

2. - E1A09

What action or actions should you take if your digital message forwarding station inadvertently forwards a communication that violates FCC rules?

Select	Answer
A	All these choices are correct
B	Notify the nearest FCC Field Engineers office
C	Notify the originating station that the communication does not comply with FCC rules
D	Discontinue forwarding the communication as soon as you become aware of it

3. - E1B03

Within what distance must an amateur station protect an FCC monitoring facility from harmful interference?

Select	Answer
A	10 miles
B	3 miles
C	30 miles
D	1 mile

4. - E1C06

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 append "/CEPT" to your call sign
B	You must bring a copy of FCC Public Notice DA 16-1048
C	You must identify in the official language of the country in which you are operating
D	The U.S. embassy must approve of your operation

5. - E1D06

What is the maximum permitted transmitter output power when operating a model craft by telecommand?

Select	Answer
A	2 watts
B	5 watts
C	1 watt
D	100 watts

6. - E1E06

Who is responsible for the proper conduct and necessary supervision during an amateur operator license examination session?

Select	Answer
A	The VEC coordinating the session
B	The FCC
C	The VE session manager
D	Each administering VE

7. - E1F02

What privileges are authorized in the U.S. to persons holding an amateur service license granted by the government of Canada?

Select	Answer
A	None, they must obtain a U.S. license
B	All privileges of the Amateur Extra Class license
C	Full privileges, up to and including those of the Amateur Extra Class license, on the 80, 40, 20, 15, and 10 meter bands
D	The operating terms and conditions of the Canadian amateur service license, not to exceed U.S. Amateur Extra Class license privileges

8. - E2A10

What type of satellite appears to stay in one position in the sky?

Select	Answer
A	Geostationary
B	LEO
C	HEO
D	Geomagnetic

9. - E2B09

What hardware, other than a receiver with SSB capability and a suitable computer, is needed to decode SSTV using Digital Radio Mondiale (DRM)?

Select	Answer
A	No other hardware is needed
B	A special notch filter to remove synchronization pulses
C	A special IF converter
D	A special front end limiter

10. - E2C07

What is the Cabrillo format?

Select	Answer
A	A standard for submission of electronic contest logs
B	A method of exchanging information during a contest QSO
C	The rules of order for meetings between contest sponsors
D	The most common set of contest rules

11. - E2D06

Which of the following describes a method of establishing EME contacts?

Select	Answer
A	Time synchronous transmissions alternately from each station
B	Judging optimum transmission times by monitoring beacons reflected from the moon
C	Storing and forwarding digital messages
D	High-speed CW identification to avoid fading

12. - E2E06

What is the most common data rate used for HF packet?

Select	Answer
A	300 baud
B	1200 baud
C	48 baud
D	110 baud

13. - E3A12

What is the cause of auroral activity?

Select	Answer
A	The interaction in the E layer of charged particles from the Sun with the Earth's magnetic field
B	The interaction in the F2 layer between the solar wind and the Van Allen belt
C	Meteor showers concentrated in the extreme northern and southern latitudes
D	An extreme low-pressure area in the polar regions

14. - E3B10

Why is chordal hop propagation desirable?

Select	Answer
A	Atmospheric noise is lower in the direction of chordal hop propagation
B	Signals travel faster along ionospheric chords
C	The signal experiences less loss compared to multi-hop using Earth as a reflector
D	The MUF for chordal hop propagation is much lower than for normal skip propagation

15. - E3C11

What does VOACAP software model?

Select	Answer
A	AC current and impedance
B	HF propagation
C	VHF radio propagation
D	AC voltage and impedance

16. - E4A08

Which of the following measures SWR?

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

17. - E4B02

What is the significance of voltmeter sensitivity expressed in ohms per volt?

Select	Answer
A	When used as an ohmmeter, the reading in ohms divided by the ohms per volt rating will determine the voltage applied to the circuit
B	When used as an ammeter, the full scale reading in amps divided by ohms per volt rating will determine the size of shunt needed
C	The full scale reading of the voltmeter multiplied by its ohms per volt rating will indicate the input impedance of the voltmeter
D	When used as a galvanometer, the reading in volts multiplied by the ohms per volt rating will determine the power drawn by the device under test

18. - E4C14

What transmit frequency might generate an image response signal in a receiver tuned to 14.300 MHz and that uses a 455 kHz IF frequency?

Select	Answer
A	14.445 MHz
B	13.845 MHz
C	15.210 MHz
D	14.755 MHz

19. - E4D12

What is the term for the reduction in receiver sensitivity caused by a strong signal near the received frequency?

Select	Answer
A	Desensitization
B	Squelch gain rollback
C	Quieting
D	Cross-modulation interference

20. - E4E06

What is one type of electrical interference that might be caused by a nearby personal computer?

Select	Answer
A	A clicking noise at intervals of a few seconds
B	The appearance of unstable modulated or unmodulated signals at specific frequencies
C	A whining type noise that continually pulses off and on
D	A loud AC hum in the audio output of your station receiver

21. - E5A01

What can cause the voltage across reactances in a series RLC circuit to be higher than the voltage applied to the entire circuit?

Select	Answer
A	Conductance
B	Capacitance
C	Resonance
D	Resistance

22. - E5B05

What happens to the magnitude of a pure reactance when it is converted to a susceptance?

Select	Answer
A	The sign is reversed
B	It is unchanged
C	It is shifted by 90 degrees
D	It becomes the reciprocal

23. - E5C12

Which point on Figure E5-1 best represents the impedance of a series circuit consisting of a 300-ohm resistor and a 19-picofarad capacitor at 21.200 MHz?

Select	Answer
A	Point 8
B	Point 7
C	Point 1
D	Point 3

24. - E5D13

How many watts are consumed in a circuit consisting of a 100-ohm resistor in series with a 100-ohm inductive reactance drawing 1 ampere?

Select	Answer
A	100 watts
B	141.4 watts
C	200 watts
D	70.7 watts

25. - E6A06

What is the beta of a bipolar junction transistor?

Select	Answer
A	The frequency at which the current gain is reduced to 0.707
B	The breakdown voltage of the base to collector junction
C	The switching speed
D	The change in collector current with respect to base current

26. - E6B06

Which of the following is a common use of a Schottky diode?

Select	Answer
A	As a rectifier in high current power supplies
B	As a variable capacitance in an automatic frequency control circuit
C	As a constant voltage reference in a power supply
D	As a VHF/UHF mixer or detector

27. - E6C02

What happens when the level of a comparator's input signal crosses the threshold?

Select	Answer
A	The feedback loop becomes unstable
B	The comparator changes its output state
C	The comparator enters latch-up
D	The IC input can be damaged

28. - E6D09

What devices are commonly used as VHF and UHF parasitic suppressors at the input and output terminals of a transistor HF amplifier?

Select	Answer
A	Steel-core toroids
B	Butterworth filters
C	Ferrite beads
D	Electrolytic capacitors

29. - E6E05

Which of the following noise figure values is typical of a low-noise UHF preamplifier?

Select	Answer
A	44 dBm
B	-20 dBm
C	-10 dB
D	2 dB

30. - E6F06

Which of these materials is most commonly used to create photoconductive devices?

Select	Answer
A	A heavy metal
B	An ordinary metal
C	A crystalline semiconductor
D	A liquid semiconductor

31. - E7A04

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

Select	Answer
A	1
B	4
C	8
D	2

32. - E7B10

In Figure E7-1, what is the purpose of R1 and R2?

Select	Answer
A	Load resistors
B	Feedback
C	Self bias
D	Voltage divider bias

33. - E7C12

What is one advantage of a Pi-matching network over an L-matching network consisting of a single inductor and a single capacitor?

Select	Answer
A	Pi-networks are more stable
B	The Q of Pi-networks can be controlled
C	L-networks cannot perform impedance transformation
D	Pi-networks provide balanced input and output

34. - E7D10

What is the primary reason that a high-frequency switching type high-voltage power supply can be both less expensive and lighter in weight than a conventional power supply?

Select	Answer
A	The inverter design does not require any output filtering
B	It uses a large power factor compensation capacitor to recover power from the unused portion of the AC cycle
C	It uses a diode bridge rectifier for increased output
D	The high frequency inverter design uses much smaller transformers and filter components for an equivalent power output

35. - E7E11

Which type of detector circuit is used for demodulating SSB signals?

Select	Answer
A	Discriminator
B	Phase detector
C	Product detector
D	Phase comparator

36. - 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 crystal-lattice filter
C	An adaptive filter
D	A Hilbert-transform filter

37. - E7G03

What is the typical input impedance of an op-amp?

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

38. - E7H07

How can an oscillator's microphonic responses be reduced?

Select	Answer
A	Reduce noise on the oscillator's power supply
B	Use NP0 capacitors
C	Increase the bias voltage
D	Mechanically isolate the oscillator circuitry from its enclosure

39. - E8A09

How many different input levels can be encoded by an analog-to-digital converter with 8-bit resolution?

Select	Answer
A	256 divided by the gain of the input amplifier
B	256
C	8 multiplied by the gain of the input amplifier
D	8

40. - 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 signals are arranged to share discrete time slots of a data transmission
C	Two or more signals are quadrature modulated to increase bandwidth efficiency
D	Two or more data streams are assigned to discrete sub-carriers on an FM transmitter

41. - E8C03

Why should phase-shifting of a PSK signal be done at the zero crossing of the RF signal?

Select	Answer
A	To minimize bandwidth
B	To improve carrier suppression
C	All these choices are correct
D	To simplify modulation

42. - E8D05

What is the most common method of reducing key clicks?

Select	Answer
A	Reduce keying waveform rise and fall times
B	Increase keying waveform rise and fall times
C	High-pass filters at the transmitter output
D	Low-pass filters at the transmitter output

43. - E9A12

How much gain does an antenna have compared to a 1/2-wavelength dipole when it has 6 dB gain over an isotropic antenna?

Select	Answer
A	3.85 dB
B	6.0 dB
C	2.79 dB
D	8.15 dB

44. - E9B05

What type of antenna pattern is shown in Figure E9-2?

Select	Answer
A	Elevation
B	Polarization
C	Radiation resistance
D	Azimuth

45. - E9C08

What is a folded dipole antenna?

Select	Answer
A	A dipole configured to provide forward gain
B	A type of ground-plane antenna
C	A half-wave dipole with an additional parallel wire connecting its two ends
D	A dipole one-quarter wavelength long

46. - E9D09

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

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

47. - E9E10

Which of these choices is an effective way to match an antenna with a 100-ohm feed point impedance to a 50-ohm coaxial cable feed line?

Select	Answer
A	Connect a 1/2 wavelength shorted stub of 75-ohm cable in parallel with the 50-ohm cable where it attaches to the antenna
B	Connect a 1/4-wavelength open stub of 300-ohm twinlead in parallel with the coaxial feed line where it connects to the antenna
C	Insert a 1/2 wavelength piece of 300-ohm twinlead in series between the antenna terminals and the 50-ohm feed cable
D	Insert a 1/4-wavelength piece of 75-ohm coaxial cable transmission line in series between the antenna terminals and the 50-ohm feed cable

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. - E9G08

What is the process of normalization with regard to a Smith chart?

Select	Answer
A	Reassigning reactance values with regard to the resistance axis
B	Reassigning resistance values with regard to the reactance axis
C	Reassigning prime center with regard to the reactance axis
D	Reassigning impedance values with regard to the prime center

50. - E9H09

What is a Pennant antenna?

Select	Answer
A	A form of rhombic antenna terminated in a variable capacitor to provide frequency diversity
B	A small, vertically oriented receiving antenna consisting of a triangular loop terminated in approximately 900 ohms
C	A stealth antenna built to look like a flagpole
D	A four-element, high-gain vertical array invented by George Pennant

Figure E5-1

Figure E7-1

Figure E9-2