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

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1. - E1A02

When using a transceiver that displays the carrier frequency of phone signals, which of the following displayed frequencies represents the lowest frequency at which a properly adjusted LSB emission will be totally within the band?

Select	Answer
A	The exact lower band edge
B	300 Hz above the lower band edge
C	3 kHz above the lower band edge
D	1 kHz above the lower band edge

2. - E1B04

What must be done before placing an amateur station within an officially designated wilderness area or wildlife preserve, or an area listed in the National Register of Historical Places?

Select	Answer
A	A letter of intent must be filed with the National Audubon Society
B	An Environmental Assessment must be submitted to the FCC
C	A form FSD-15 must be submitted to the Department of the Interior
D	A proposal must be submitted to the National Park Service

3. - E1C02

What is meant by automatic control of a station?

Select	Answer
A	A station operating with its output power controlled automatically
B	The use of a control link between a control point and a locally controlled station
C	Remotely controlling a station's antenna pattern through a directional control link
D	The use of devices and procedures for control so that the control operator does not have to be present at a control point

4. - E1D01

What is the definition of the term telemetry?

Select	Answer
A	Two-way radiotelephone transmissions in excess of 1000 feet
B	Two-way single channel transmissions of data
C	One-way transmission of measurements at a distance from the measuring instrument
D	One-way transmission that initiates, modifies, or terminates the functions of a device at a distance

5. - E1E14

For which types of out-of-pocket expenses do the Part 97 rules state that VEs and VECs may be reimbursed?

Select	Answer
A	Providing amateur operator license examination preparation training materials
B	Preparing, processing, administering and coordinating an examination for an amateur radio license
C	Teaching an amateur operator license examination preparation course
D	No expenses are authorized for reimbursement

6. - E1F12

Who may be the control operator of an auxiliary station?

Select	Answer
A	Only Amateur Extra Class operators
B	Any licensed amateur operator
C	Only Technician, General, Advanced or Amateur Extra Class operators
D	Only General, Advanced or Amateur Extra Class operators

7. - E2A07

Which of the following types of signals can be relayed through a linear transponder?

Select	Answer
A	FM and CW
B	All of these choices are correct
C	SSB and SSTV
D	PSK and Packet

8. - E2B19

What special operating frequency restrictions are imposed on slow scan TV transmissions?

Select	Answer
A	They are restricted to 7.245 MHz, 14.245 MHz, 21.345 MHz, and 28.945 MHz
B	They are restricted to phone band segments and their bandwidth can be no greater than that of a voice signal of the same modulation type
C	They are not permitted above 54 MHz
D	None; they are allowed on all amateur frequencies

9. - E2C12

What might help to restore contact when DX signals become too weak to copy across an entire HF band a few hours after sunset?

Select	Answer
A	Wait 24 hours before attempting another communication on the band
B	Wait 90 minutes or so for the signal degradation to pass
C	Switch to a lower frequency HF band
D	Switch to a higher frequency HF band

10. - E2D03

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

Select	Answer
A	Olivia
B	JT65
C	FSK441
D	PACTOR III

11. - E2E07

What is the typical bandwidth of a properly modulated MFSK16 signal?

Select	Answer
A	2.16 kHz
B	31 Hz
C	316 Hz
D	550 Hz

12. - E3A15

What is an electromagnetic wave?

Select	Answer
A	A wave consisting of an electric field and a magnetic field oscillating at right angles to each other
B	A wave consisting of two electric fields at parallel right angles to each other
C	A wave consisting of two magnetic fields at right angles to each other
D	A wave of alternating current, in the core of an electromagnet

13. - E3B10

What is the cause of gray-line propagation?

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

14. - E3C03

Which of the following signal paths is most likely to experience high levels of absorption when the A index or K index is elevated?

Select	Answer
A	Sporadic-E
B	Transequatorial propagation
C	Polar paths
D	NVIS

15. - E4A14

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

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

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	165.2 Hz
B	14.652 kHz
C	146.52 Hz
D	1.4652 MHz

17. - E4C11

Which of the following is a desirable amount of selectivity for an amateur SSB phone receiver?

Select	Answer
A	4.8 kHz
B	1 kHz
C	4.2 kHz
D	2.4 kHz

18. - E4D14

Which of the following is a way to reduce the likelihood of receiver desensitization?

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

19. - E4E15

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

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

20. - E5A15

Which of the following can increase Q for inductors and capacitors?

Select	Answer
A	Lower self-resonant frequency
B	Lower losses
C	Lower reactance
D	Higher self-resonant frequency

21. - 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?

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

22. - E5C09

When using rectangular coordinates to graph the impedance of a circuit, what does the horizontal axis represent?

Select	Answer
A	The difference between the resistive and reactive components
B	The sum of the reactive and resistive components
C	Reactive component
D	Resistive component

23. - E5D03

What is microstrip?

Select	Answer
A	Precision printed circuit conductors above a ground plane that provide constant impedance interconnects at microwave frequencies
B	Miniature coax used for low power applications
C	Short lengths of coax mounted on printed circuit boards to minimize time delay between microwave circuits
D	Lightweight transmission line made of common zip cord

24. - E6A04

What is the name given to an impurity atom that adds holes to a semiconductor crystal structure?

Select	Answer
A	Insulator impurity
B	Donor impurity
C	Acceptor impurity
D	N-type impurity

25. - E6B13

What type of bias is required for an LED to emit light?

Select	Answer
A	Forward bias
B	Zero bias
C	Inductive bias
D	Reverse bias

26. - E6C08

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

Select	Answer
A	3
B	4
C	2
D	1

27. - E6D17

Why should core saturation of a conventional impedance matching transformer be avoided?

Select	Answer
A	Magnetic flux would increase with frequency
B	Harmonics and distortion could result
C	Temporary changes of the core permeability could result
D	RF susceptance would increase

28. - E6E07

Which of the following is typically used to construct a MMIC-based microwave amplifier?

Select	Answer
A	Ground-plane construction
B	Point-to-point construction
C	Microstrip construction
D	Wave-soldering construction

29. - E6F02

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

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

30. - E7A06

What is a characteristic of a monostable multivibrator?

Select	Answer
A	It stores one bit of data in either a 0 or 1 state
B	It produces a continuous square wave oscillating between 1 and 0
C	It maintains a constant output voltage, regardless of variations in the input voltage
D	It switches momentarily to the opposite binary state and then returns to its original state after a set time

31. - E7B16

What is the effect of intermodulation products in a linear power amplifier?

Select	Answer
A	Creation of parasitic oscillations
B	Transmission of spurious signals
C	Low efficiency
D	All of these choices are correct

32. - E7C02

Which of the following is a property of a T-network with series capacitors and a parallel shunt inductor?

Select	Answer
A	It is a band-pass filter
B	It is a notch filter
C	It is a low-pass filter
D	It is a high-pass filter

33. - E7D07

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

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

34. - E7E05

What circuit is added to an FM transmitter to boost the higher audio frequencies?

Select	Answer
A	A de-emphasis network
B	A heterodyne suppressor
C	An audio prescaler
D	A pre-emphasis network

35. - E7F17

What do the letters I and Q in I/Q Modulation represent?

Select	Answer
A	Instantaneous and Quasi-stable
B	In-phase and Quadrature
C	Inactive and Quiescent
D	Instantaneous and Quenched

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	47
B	24
C	94
D	0.21

37. - E7H02

Which describes a microphonic?

Select	Answer
A	Distortion caused by RF pickup on the microphone cable
B	Changes in oscillator frequency due to mechanical vibration
C	An IC used for amplifying microphone signals
D	Excess loading of the microphone by an oscillator

38. - E8A08

Why would a direct or flash conversion analog-to-digital converter be useful for a software defined radio?

Select	Answer
A	All of these choices are correct
B	Very high speed allows digitizing high frequencies
C	Immunity to out of sequence coding reduces spurious responses
D	Very low power consumption decreases frequency drift

39. - E8B08

What describes Orthogonal Frequency Division Multiplexing?

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

40. - E8C08

How does ARQ accomplish error correction?

Select	Answer
A	Special polynomial codes provide automatic correction
B	If errors are detected, a retransmission is requested
C	If errors are detected, redundant data is substituted
D	Special binary codes provide automatic correction

41. - E8D01

Why are received spread spectrum signals resistant to interference?

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

42. - E9A16

What is the effective radiated power relative to a dipole of a repeater station with 200 watts transmitter power output, 4 dB feed line loss, 3.2 dB duplexer loss, 0.8 dB circulator loss, and 10 dBd antenna gain?

Select	Answer
A	317 watts
B	126 watts
C	300 watts
D	2000 watts

43. - E9B02

In the antenna radiation pattern shown in Figure E9-1, what is the front-to-back ratio?

Select	Answer
A	18 dB
B	14 dB
C	36 dB
D	24 dB

44. - E9C02

What is the radiation pattern of two 1/4 wavelength vertical antennas spaced 1/4 wavelength apart and fed 90 degrees out of phase?

Select	Answer
A	A figure-8 end-fire along the axis of the array
B	Omni-directional
C	A figure-8 broadside to the axis of the array
D	Cardioid

45. - E9D04

Why should an HF mobile antenna loading coil have a high ratio of reactance to resistance?

Select	Answer
A	To maximize losses
B	To minimize the Q
C	To minimize losses
D	To swamp out harmonics

46. - E9E05

How must the driven element in a 3-element Yagi be tuned to use a hairpin matching system?

Select	Answer
A	The driven element reactance must be inductive
B	The driven element radiation resistance must be higher than the characteristic impedance of the transmission line
C	The driven element reactance must be capacitive
D	The driven element resonance must be lower than the operating frequency

47. - E9F13

What impedance does a 1/4 wavelength transmission line present to a generator when the line is shorted at the far end?

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

48. - E9G02

What type of coordinate system is used in a Smith chart?

Select	Answer
A	Resistance lines and reactance chords
B	Voltage circles and current arcs
C	Resistance circles and reactance arcs
D	Voltage lines and current chords

49. - E9H06

What is the triangulation method of direction finding?

Select	Answer
A	A fixed receiving station uses three different antennas to plot the location of the signal source
B	Antenna headings from several different receiving locations are used to locate the signal source
C	The geometric angles of sky waves from the source are used to determine its position
D	A fixed receiving station plots three headings to the signal source

50. - E0A03

Which of the following would be a practical way to estimate whether the RF fields produced by an amateur radio station are within permissible MPE limits?

Select	Answer
A	All of the choices are correct
B	Use an antenna modeling program to calculate field strength at accessible locations
C	Use a hand calculator plus Smith-chart equations to calculate the fields
D	Use a calibrated antenna analyzer

Figure E6-5

Figure E7-3

Figure E7-4

Figure E9-1