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

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1. - E1A08

If a station in a message forwarding system inadvertently forwards a message that is in violation of FCC rules, who is primarily accountable for the rules violation?

Select	Answer
A	The control operator of the originating station
B	The control operators of all the stations in the system
C	The control operators of all the stations in the system not authenticating the source from which they accept communications
D	The control operator of the packet bulletin board station

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

3. - E1C13

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 bring a copy of FCC Public Notice DA 11-221
B	You must append "/CEPT" to your call sign
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

4. - E1D08

Which VHF amateur service bands have frequencies available for space stations?

Select	Answer
A	2 meters and 1.25 meters
B	6 meters, 2 meters, and 1.25 meters
C	2 meters
D	6 meters and 2 meters

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	Teaching an amateur operator license examination preparation course
C	No expenses are authorized for reimbursement
D	Preparing, processing, administering and coordinating an examination for an amateur radio license

6. - E1F05

Amateur stations may not transmit in which of the following frequency segments if they are located in the contiguous 48 states and north of Line A?

Select	Answer
A	420 MHz - 430 MHz
B	222 MHz - 223 MHz
C	53 MHz - 54 MHz
D	440 MHz - 450 MHz

7. - E2A12

What is one way to predict the location of a satellite at a given time?

Select	Answer
A	By subtracting the mean anomaly from the orbital inclination
B	By adding the mean anomaly to the orbital inclination
C	By means of the Doppler data for the specified satellite
D	By calculations using the Keplerian elements for the specified satellite

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

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	Frequency division multiplex in the 24 GHz band
C	Store and forward on the 440 MHz band
D	Multiple Frequency Shift Keying in the 10 GHz band

10. - E2D12

How does JT65 improve EME communications?

Select	Answer
A	It controls the receiver to track Doppler shift
B	It can decode signals many dB below the noise floor using FEC
C	It supplies signals to guide the antenna to track the Moon
D	All of these choices are correct

11. - E2E03

How is the timing of JT65 contacts organized?

Select	Answer
A	Alternating transmissions at 1 minute intervals
B	Stations take turns on alternate days
C	It depends on the lunar phase
D	By exchanging ACK/NAK packets

12. - 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	Meteor showers concentrated in the extreme northern and southern latitudes
C	The interaction in the F2 layer between the solar wind and the Van Allen belt
D	A low sunspot level combined with tropospheric ducting

13. - E3B08

What type of HF propagation is probably occurring if radio signals travel along the terminator between daylight and darkness?

Select	Answer
A	Sporadic-E
B	Long-path
C	Transequatorial
D	Gray-line

14. - E3C02

What is indicated by a rising A or K index?

Select	Answer
A	An increase in the critical frequency
B	Higher levels of solar UV radiation
C	Decreasing disruption of the geomagnetic field
D	Increasing disruption of the geomagnetic field

15. - E4A14

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

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

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. - E4C10

Which of the following is a desirable amount of selectivity for an amateur RTTY HF receiver?

Select	Answer
A	300 Hz
B	100 Hz
C	2400 Hz
D	6000 Hz

18. - E4D03

How can intermodulation interference between two repeaters occur?

Select	Answer
A	When the repeaters are in close proximity and the signals mix in the final amplifier of one or both transmitters
B	When the signals from the transmitters are reflected out of phase from airplanes passing overhead
C	When the signals from the transmitters are reflected in phase from airplanes passing overhead
D	When the repeaters are in close proximity and the signals cause feedback in the final amplifier of one or both transmitters

19. - E4E05

How can noise from an electric motor be suppressed?

Select	Answer
A	By using a ground-fault current interrupter in the circuit used to power the motor
B	By installing a bypass capacitor in series with the motor leads
C	By installing a brute-force AC-line filter in series with the motor leads
D	By installing a high pass filter in series with the motor's power leads

20. - E5A15

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

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

21. - E5B02

What is the term for the time it takes for a charged capacitor in an RC circuit to discharge to 36.8% of its initial voltage?

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

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. - E5D18

How many watts are consumed in a circuit having a power factor of 0.71 if the apparent power is 500VA?

Select	Answer
A	252 W
B	704 W
C	1.42 mW
D	355 W

24. - E6A08

What term indicates the frequency at which the grounded-base current gain of a transistor has decreased to 0.7 of the gain obtainable at 1 kHz?

Select	Answer
A	Corner frequency
B	Alpha cutoff frequency
C	Alpha rejection frequency
D	Beta cutoff frequency

25. - E6B11

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

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

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

27. - E6D05

What is one reason for using ferrite cores rather than powdered-iron in an inductor?

Select	Answer
A	Ferrite toroids generally have better temperature stability
B	Ferrite toroids generally have lower initial permeability
C	Ferrite toroids are easier to use with surface mount technology
D	Ferrite toroids generally require fewer turns to produce a given inductance value

28. - E6E10

What is the packaging technique in which leadless components are soldered directly to circuit boards?

Select	Answer
A	Stripped lead
B	Surface mount
C	Virtual lead mounting
D	Direct soldering

29. - E6F01

What is photoconductivity?

Select	Answer
A	The decreased conductivity of an illuminated semiconductor
B	The conversion of electromotive energy to photon energy
C	The conversion of photon energy to electromotive energy
D	The increased conductivity of an illuminated semiconductor

30. - E7A04

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

Select	Answer
A	8
B	4
C	2
D	1

31. - E7B05

What can be done to prevent unwanted oscillations in an RF power amplifier?

Select	Answer
A	Tune the stage for maximum SWR
B	Tune both the input and output for maximum power
C	Install parasitic suppressors and/or neutralize the stage
D	Use a phase inverter in the output filter

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

33. - E7D15

What is the purpose of a "step-start" circuit in a high voltage power supply?

Select	Answer
A	To allow the filter capacitors to charge gradually
B	To compensate for variations of the incoming line voltage
C	To allow for remote control of the power supply
D	To provide a dual-voltage output for reduced power applications

34. - E7E03

How does an analog phase modulator function?

Select	Answer
A	By varying the tuning of an amplifier tank circuit to produce AM signals
B	By varying the tuning of a microphone preamplifier to produce PM signals
C	By varying the tuning of an amplifier tank circuit to produce PM signals
D	By varying the tuning of a microphone preamplifier to produce AM signals

35. - E7F13

What is the function of taps in a digital signal processing filter?

Select	Answer
A	Provide incremental signal delays for filter algorithms
B	Select the point at which baseband signals are generated
C	To reduce excess signal pressure levels
D	Provide access for debugging software

36. - E7G05

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

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

37. - E7H08

Which of the following components can be used to reduce thermal drift in crystal oscillators?

Select	Answer
A	Wirewound resistors
B	NP0 capacitors
C	Toroidal inductors
D	Non-inductive resistors

38. - E8A05

What would be the most accurate way of measuring the RMS voltage of a complex waveform?

Select	Answer
A	By measuring the heating effect in a known resistor
B	By measuring the voltage with a D'Arsonval meter
C	By using an absorption wave meter
D	By using a grid dip meter

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	0.47
B	0.214
C	47
D	2.14

40. - E8C02

What is the definition of symbol rate in a digital transmission?

Select	Answer
A	The number of control characters in a message packet
B	The number of characters carried per second by the station-to-station link
C	The duration of each bit in a message sent over the air
D	The rate at which the waveform of a transmitted signal changes to convey information

41. - E8D01

Why are received spread spectrum signals resistant to interference?

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

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	2000 watts
D	300 watts

43. - E9B16

How many elevation lobes appear in the forward direction of the antenna radiation pattern shown in Figure E9-2?

Select	Answer
A	4
B	7
C	3
D	1

44. - E9C01

What is the radiation pattern of two 1/4-wavelength vertical antennas spaced 1/2-wavelength apart and fed 180 degrees out of phase?

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

45. - 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 losses
C	To lower the Q
D	To cancel capacitive reactance

46. - E9E12

What is the primary purpose of a phasing line when used with an antenna having multiple driven elements?

Select	Answer
A	It makes sure the antenna has a low-angle radiation pattern
B	It allows single-band antennas to operate on other bands
C	It prevents reflected power from traveling back down the feed line and causing harmonic radiation from the transmitter
D	It ensures that each driven element operates in concert with the others to create the desired antenna pattern

47. - E9F09

What is the approximate physical length of a solid polyethylene dielectric coaxial transmission line that is electrically one-quarter wavelength long at 7.2 MHz?

Select	Answer
A	10 meters
B	24 meters
C	50 meters
D	6.9 meters

48. - E9G01

Which of the following can be calculated using a Smith chart?

Select	Answer
A	Radiation resistance
B	Impedance along transmission lines
C	Radio propagation
D	Antenna radiation pattern

49. - 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

50. - E0A02

When evaluating RF exposure levels from your station at a neighbor's home, what must you do?

Select	Answer
A	Make sure signals from your station are less than the uncontrolled MPE limits
B	Advise your neighbors of the results of your tests
C	Make sure signals from your station are less than the controlled MPE limits
D	You need only evaluate exposure levels on your own property

Figure E9-2