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	60 Hz
B	2.8 kHz
C	1.5 kHz
D	170 Hz

2. - E1B02

Which of the following factors might cause the physical location of an amateur station apparatus or antenna structure to be restricted?

Select	Answer
A	The location is of geographical or horticultural importance
B	The location is in an ITU Zone designated for coordination with one or more foreign governments
C	The location is near an area of political conflict
D	The location is of environmental importance or significant in American history, architecture, or culture

3. - E1C09

Which of these ranges of frequencies is available for an automatically controlled repeater operating below 30 MHz?

Select	Answer
A	18.110 MHz - 18.168 MHz
B	29.500 MHz - 29.700 MHz
C	10.100 MHz - 10.150 MHz
D	24.940 MHz - 24.990 MHz

4. - E1D10

Which amateur stations are eligible to be telecommand stations?

Select	Answer
A	Any amateur station designated by NASA
B	Any amateur station so designated by the space station licensee, subject to the privileges of the class of operator license held by the control operator
C	Any amateur station so designated by the ITU
D	All of these choices are correct

5. - E1E10

What must the administering VEs do after the administration of a successful examination for an amateur operator license?

Select	Answer
A	They must collect and send the documents to the NCVEC for grading
B	They must collect and send the documents to the FCC according to instructions
C	They must collect and submit the documents to the coordinating VEC for grading
D	They must submit the application document to the coordinating VEC according to the coordinating VEC instructions

6. - E1F09

Which of the following conditions apply when transmitting spread spectrum emission?

Select	Answer
A	The transmitting station must be in an area regulated by the FCC or in a country that permits SS emissions
B	A station transmitting SS emission must not cause harmful interference to other stations employing other authorized emissions
C	The transmission must not be used to obscure the meaning of any communication
D	All of these choices are correct

7. - E2A06

On what band would a satellite receive signals if it were operating in mode U/V?

Select	Answer
A	50.0 MHz - 50.2 MHz
B	435 MHz - 438 MHz
C	144 MHz - 146 MHz
D	29.5 MHz - 29.7 MHz

8. - E2B02

How many horizontal lines make up a fast-scan (NTSC) television frame?

Select	Answer
A	525
B	1080
C	60
D	30

9. - E2C06

During a VHF/UHF contest, in which band segment would you expect to find the highest level of activity?

Select	Answer
A	In the weak signal segment of the band, with most of the activity near the calling frequency
B	In the middle of each band, usually on the national calling frequency
C	In the middle of the band, usually 25 kHz above the national calling frequency
D	At the top of each band, usually in a segment reserved for contests

10. - E2D02

Which of the following is a good technique for making meteor scatter contacts?

Select	Answer
A	15 second timed transmission sequences with stations alternating based on location
B	Use of high speed CW or digital modes
C	All of these choices are correct
D	Short transmission with rapidly repeated call signs and signal reports

11. - E2E09

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

Select	Answer
A	RTTY
B	PSK31
C	MT63
D	PACTOR

12. - E3A02

What characterizes libration fading of an EME signal?

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

13. - E3B10

What is the cause of gray-line propagation?

Select	Answer
A	In darkness, solar absorption drops greatly while atmospheric ionization remains steady
B	At twilight and sunrise, D-layer absorption is low while E-layer and F-layer propagation remains high
C	At mid-afternoon, the Sun heats the ionosphere decreasing radio wave refraction and the MUF
D	At midday, the Sun super heats the ionosphere causing increased refraction of radio waves

14. - E3C07

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

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

15. - E4A04

What determines the upper frequency limit for a computer soundcard-based oscilloscope program?

Select	Answer
A	Q of the interface of the interface circuit
B	Amount of memory on the soundcard
C	All of these choices are correct
D	Analog-to-digital conversion speed of the soundcard

16. - E4B09

What is indicated if the current reading on an RF ammeter placed in series with the antenna feed line of a transmitter increases as the transmitter is tuned to resonance?

Select	Answer
A	There is more power going into the antenna
B	There is possibly a short to ground in the feed line
C	There is an impedance mismatch between the antenna and feed line
D	The transmitter is not properly neutralized

17. - E4C02

Which of the following portions of a receiver can be effective in eliminating image signal interference?

Select	Answer
A	A front-end filter or pre-selector
B	A notch filter
C	A properly adjusted product detector
D	A narrow IF filter

18. - E4D13

Which of the following can cause receiver desensitization?

Select	Answer
A	Strong adjacent channel signals
B	Squelch gain misadjusted
C	Audio bias adjusted too high
D	Audio gain adjusted too low

19. - E4E15

Which of the following can cause shielded cables to radiate or receive interference?

Select	Answer
A	Common mode currents on the shield and conductors
B	Use of braided shielding material
C	Tying all ground connections to a common point resulting in differential mode currents in the shield
D	Low inductance ground connections at both ends of the shield

20. - E5A08

What is the phase relationship between the current through and the voltage across a series resonant circuit at resonance?

Select	Answer
A	The voltage leads the current by 90 degrees
B	The voltage and current are in phase
C	The current leads the voltage by 90 degrees
D	The voltage and current are 180 degrees out of phase

21. - E5B06

What is susceptance?

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

22. - E5C08

What coordinate system is often used to display the phase angle of a circuit containing resistance, inductive and/or capacitive reactance?

Select	Answer
A	Polar coordinates
B	Faraday grid
C	Maidenhead grid
D	Elliptical coordinates

23. - E5D10

How can the true power be determined in an AC circuit where the voltage and current are out of phase?

Select	Answer
A	By dividing the reactive power by the power factor
B	By multiplying the apparent power times the power factor
C	By dividing the apparent power by the power factor
D	By multiplying the reactive power times the power factor

24. - E6A11

In Figure E6-2, what is the schematic symbol for a P-channel junction FET?

Select	Answer
A	6
B	3
C	1
D	2

25. - E6B12

What is one common use for PIN diodes?

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

26. - E6C07

What best describes a pull-up or pull-down resistor?

Select	Answer
A	A resistor in a keying circuit used to reduce key clicks
B	A resistor connected to the positive or negative supply line used to establish a voltage when an input or output is an open circuit
C	A resistor connected to an op-amp output that only functions when the logic output is false
D	A resistor that insures that an oscillator frequency does not drive lower over time

27. - E6D02

What is the equivalent circuit of a quartz crystal?

Select	Answer
A	Motional capacitance, motional inductance, loss resistance, and a capacitor representing electrode and stray capacitance all in series
B	Motional inductance and loss resistance in series, paralleled with motional capacitance and a capacitor representing electrode and stray capacitance
C	Motional capacitance, motional inductance, and loss resistance in series, all in parallel with a shunt capacitor representing electrode and stray capacitance
D	Motional capacitance, motional inductance, loss resistance, and a capacitor representing electrode and stray capacitance all in parallel

28. - E6E08

How is voltage from a power supply normally furnished to the most common type of monolithic microwave integrated circuit (MMIC)?

Select	Answer
A	MMICs require no operating bias
B	Directly to the bias voltage (VCC IN) lead
C	Through a capacitor and RF choke connected to the amplifier input lead
D	Through a resistor and/or RF choke connected to the amplifier output lead

29. - E6F13

What is a liquid crystal display (LCD)?

Select	Answer
A	A modern replacement for a quartz crystal oscillator which displays its fundamental frequency
B	A display that uses a glowing liquid to remain brightly lit in dim light
C	A frequency-determining unit for a transmitter or receiver
D	A display utilizing a crystalline liquid and polarizing filters which becomes opaque when voltage is applied

30. - E7A02

What is the function of a decade counter digital IC?

Select	Answer
A	It produces one output pulse for every ten input pulses
B	It adds two decimal numbers together
C	It decodes a decimal number for display on a seven segment LED display
D	It produces ten output pulses for every input pulse

31. - E7B15

What is one way to prevent thermal runaway in a bipolar transistor amplifier?

Select	Answer
A	Neutralization
B	All of these choices are correct
C	Select transistors with high beta
D	Use a resistor in series with the emitter

32. - E7C13

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	The Q of Pi-networks can be varied depending on the component values chosen
B	Pi-networks are designed for balanced input and output
C	L-networks cannot perform impedance transformation
D	Pi-networks have fewer components

33. - E7D14

What is one purpose of a "bleeder" resistor in a conventional unregulated power supply?

Select	Answer
A	To balance the low-voltage filament windings
B	To improve output voltage regulation
C	To boost the amount of output current
D	To cut down on waste heat generated by the power supply

34. - E7E01

Which of the following can be used to generate FM phone emissions?

Select	Answer
A	A reactance modulator on the final amplifier
B	A balanced modulator on the audio amplifier
C	A balanced modulator on the oscillator
D	A reactance modulator on the oscillator

35. - E7F03

What type of digital signal processing filter is used to generate an SSB signal?

Select	Answer
A	A notch filter
B	An elliptical filter
C	A Hilbert-transform filter
D	An adaptive filter

36. - E7G07

What magnitude of voltage gain can be expected from the circuit in Figure E7-4 when R1 is 10 ohms and RF is 470 ohms?

Select	Answer
A	0.21
B	47
C	24
D	94

37. - E7H04

How is positive feedback supplied in a Colpitts oscillator?

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

38. - E8A11

What type of information can be conveyed using digital waveforms?

Select	Answer
A	Human speech
B	Data
C	All of these choices are correct
D	Video signals

39. - E8B06

What is the deviation ratio of an FM-phone signal having a maximum frequency swing of plus or minus 7.5 kHz when the maximum modulation frequency is 3.5 kHz?

Select	Answer
A	2.14
B	0.47
C	47
D	0.214

40. - E8C11

What is the relationship between symbol rate and baud?

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

41. - E8D03

How does the spread spectrum technique of frequency hopping work?

Select	Answer
A	A pseudo-random binary bit stream is used to shift the phase of an RF carrier very rapidly in a particular sequence
B	If interference is detected by the receiver it will signal the transmitter to change frequencies
C	The frequency of the transmitted signal is changed very rapidly according to a particular sequence also used by the receiving station
D	If interference is detected by the receiver it will signal the transmitter to wait until the frequency is clear

42. - E9A14

What is meant by the radiation resistance of an antenna?

Select	Answer
A	The value of a resistance that would dissipate the same amount of power as that radiated from an antenna
B	The specific impedance of the 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

43. - E9B13

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

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

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. - E9D07

What is an advantage of using top loading in a shortened HF vertical antenna?

Select	Answer
A	Higher losses
B	Greater structural strength
C	Improved radiation efficiency
D	Lower Q

46. - 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 1/4-wavelength open stub of 300 ohm twin-lead in parallel with the coaxial feed line where it connects to the antenna
B	Insert a 1/2 wavelength piece of 300 ohm twin-lead in series between the antenna terminals and the 50 ohm feed cable
C	Connect 1/2 wavelength shorted stub of 75 ohm cable in parallel with the 50 ohm cable where it attaches to the antenna
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

47. - E9F04

What is the typical velocity factor for a coaxial cable with solid polyethylene dielectric?

Select	Answer
A	0.30
B	0.10
C	0.66
D	2.70

48. - E9G05

What type of chart is shown in Figure E9-3?

Select	Answer
A	Free space radiation directivity chart
B	Azimuth angle radiation pattern chart
C	Elevation angle radiation pattern chart
D	Smith chart

49. - E9H07

Why is it advisable to use an RF attenuator on a receiver being used for direction finding?

Select	Answer
A	It reduces loss of received signals caused by antenna pattern nulls, thereby increasing sensitivity
B	It compensates for the effects of an isotropic antenna, thereby improving directivity
C	It narrows the bandwidth of the received signal to improve signal to noise ratio
D	It prevents receiver overload which could make it difficult to determine peaks or nulls

50. - E0A09

Which insulating material commonly used as a thermal conductor for some types of electronic devices is extremely toxic if broken or crushed and the particles are accidentally inhaled?

Select	Answer
A	Beryllium Oxide
B	Mica
C	Zinc oxide
D	Uranium Hexafluoride

Figure E6-2

Figure E7-4

Figure E9-3