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

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1. - 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	Zinc oxide
B	Beryllium Oxide
C	Mica
D	Uranium Hexafluoride

2. - 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 not authenticating the source from which they accept communications
C	The control operators of all the stations in the system
D	The control operator of the packet bulletin board station

3. - E1B08

What limitations may the FCC place on an amateur station if its signal causes interference to domestic broadcast reception, assuming that the receivers involved are of good engineering design?

Select	Answer
A	The amateur station must cease operation on all frequencies below 30 MHz
B	The amateur station must avoid transmitting during certain hours on frequencies that cause the interference
C	The amateur station must cease operation on all frequencies above 30 MHz
D	The amateur station must cease operation

4. - E1C07

At what level below a signal's mean power level is its bandwidth determined according to FCC rules?

Select	Answer
A	23 dB
B	6 dB
C	26 dB
D	3 dB

5. - E1D09

Which UHF amateur bands have frequencies authorized for space stations?

Select	Answer
A	70 cm and 33 cm
B	70 cm only
C	33 cm and 13 cm
D	70 cm and 13 cm

6. - E1E12

What must the VE team do with the application form if the examinee does not pass the exam?

Select	Answer
A	Destroy the application form
B	Send the application form to the FCC and inform the FCC of the grade
C	Maintain the application form with the VEC's records
D	Return the application document to the examinee

7. - E1F04

Which of the following geographic descriptions approximately describes "Line A"?

Select	Answer
A	A line roughly parallel to and east of the U.S. Pacific coastline
B	A line roughly parallel to and north of the border between the U.S. and Mexico
C	A line roughly parallel to and west of the U.S. Atlantic coastline
D	A line roughly parallel to and south of the border between the U.S. and Canada

8. - E2A02

Which of the following occurs when a satellite is using an inverting linear transponder?

Select	Answer
A	Signal position in the band is reversed
B	All these choices are correct
C	Upper sideband on the uplink becomes lower sideband on the downlink, and vice versa
D	Doppler shift is reduced because the uplink and downlink shifts are in opposite directions

9. - E2B10

What aspect of an analog slow-scan television signal encodes the brightness of the picture?

Select	Answer
A	Tone amplitude
B	Sync amplitude
C	Tone frequency
D	Sync frequency

10. - E2C05

What is the function of a DX QSL Manager?

Select	Answer
A	To handle the receiving and sending of confirmation cards for a DX station
B	To relay calls to and from a DX station
C	To run a net to allow many stations to contact a rare DX station
D	To allocate frequencies for DXpeditions

11. - E2D07

What digital protocol is used by APRS?

Select	Answer
A	802.11
B	AX.25
C	PACTOR
D	AMTOR

12. - E2E11

What is the difference between direct FSK and audio FSK?

Select	Answer
A	Only direct FSK can be decoded by computer
B	Direct FSK applies the data signal to the transmitter VFO, while AFSK transmits tones via phone
C	Direct FSK occupies less bandwidth
D	Direct FSK can transmit faster baud rates

13. - E3A03

When scheduling EME contacts, which of these conditions will generally result in the least path loss?

Select	Answer
A	When the moon is at perigee
B	When the moon is at apogee
C	When the MUF is above 30 MHz
D	When the moon is full

14. - E3B10

Why is chordal hop propagation desirable?

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

15. - E3C06

By how much does the VHF/UHF radio horizon distance exceed the geometric horizon?

Select	Answer
A	By approximately twice the distance
B	By approximately 50 percent of the distance
C	By approximately four times the distance
D	By approximately 15 percent of the distance

16. - E4A06

What is the effect of aliasing on a digital oscilloscope caused by setting the time base too slow?

Select	Answer
A	All signals will have a DC offset
B	Excessive blanking occurs, which prevents display of the signal
C	Calibration of the vertical scale is no longer valid
D	A false, jittery low-frequency version of the signal is displayed

17. - E4B11

Which of the following can be measured with a vector network analyzer?

Select	Answer
A	Input impedance
B	Reflection coefficient
C	Output impedance
D	All these choices are correct

18. - E4C15

What is reciprocal mixing?

Select	Answer
A	Local oscillator phase noise mixing with adjacent strong signals to create interference to desired signals
B	In-phase signals cancelling in a mixer resulting in loss of receiver sensitivity
C	Two out-of-band signals mixing to generate an in-band spurious signal
D	Two digital signals combining from alternate time slots

19. - E4D07

Which of the following reduces the likelihood of receiver desensitization?

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

20. - E4E05

How can radio frequency interference from an AC motor be suppressed?

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

21. - E5A08

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

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

22. - E5B08

What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 100 ohms, R is 100 ohms, and XL is 75 ohms?

Select	Answer
A	76 degrees with the voltage lagging the current
B	14 degrees with the voltage leading the current
C	14 degrees with the voltage lagging the current
D	76 degrees with the voltage leading the current

23. - E5C05

What is the name of the diagram used to show the phase relationship between impedances at a given frequency?

Select	Answer
A	Far field diagram
B	Venn diagram
C	Near field diagram
D	Phasor diagram

24. - E5D12

How many watts are consumed in a circuit having a power factor of 0.2 if the input is 100 VAC at 4 amperes?

Select	Answer
A	2000 watts
B	50 watts
C	80 watts
D	400 watts

25. - E6A11

In Figure E6-1, what is the schematic symbol for a P-channel junction FET?

Select	Answer
A	2
B	1
C	3
D	6

26. - E6B03

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

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

27. - E6C09

What is a Programmable Logic Device (PLD)?

Select	Answer
A	A programmable collection of logic gates and circuits in a single integrated circuit
B	A type of transistor whose gain can be changed by digital logic circuits
C	A logic circuit that can be modified during use
D	Programmable equipment used for testing digital logic integrated circuits

28. - 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, loss resistance, and a capacitor representing electrode and stray capacitance all in parallel
D	Motional capacitance, motional inductance, and loss resistance in series, all in parallel with a shunt capacitor representing electrode and stray capacitance

29. - E6E10

What advantage does surface-mount technology offer at RF compared to using through-hole components?

Select	Answer
A	Components have less parasitic inductance and capacitance
B	Smaller circuit area
C	Shorter circuit-board traces
D	All these choices are correct

30. - E6F09

What is the efficiency of a photovoltaic cell?

Select	Answer
A	The relative fraction of light that is converted to current
B	The open-circuit voltage divided by the short-circuit current under full illumination
C	Cost per kilowatt-hour generated
D	The output RF power divided by the input DC power

31. - E7A05

Which of the following is a circuit that continuously alternates between two states without an external clock?

Select	Answer
A	J-K flip-flop
B	Astable multivibrator
C	Monostable multivibrator
D	T flip-flop

32. - E7B13

Which of the following describes an emitter follower (or common collector) amplifier?

Select	Answer
A	An OR circuit with only one emitter used for output
B	A differential amplifier with both inputs fed to the emitter of the input transistor
C	An amplifier with a low impedance output that follows the base input voltage
D	A two-transistor amplifier with the emitters sharing a common bias resistor

33. - E7C01

How are the capacitors and inductors of a low-pass filter Pi-network arranged between the network's input and output?

Select	Answer
A	Two capacitors are in series between the input and output, and an inductor is connected between the two capacitors and ground
B	An inductor is connected between the input and ground, another inductor is connected between the output and ground, and a capacitor is connected between the input and output
C	Two inductors are in series between the input and output, and a capacitor is connected between the two inductors and ground
D	A capacitor is connected between the input and ground, another capacitor is connected between the output and ground, and an inductor is connected between input and output

34. - E7D06

What is the purpose of Q1 in the circuit shown in Figure E7-2?

Select	Answer
A	It provides D1 with current
B	It provides negative feedback to improve regulation
C	It provides a constant load for the voltage source
D	It controls the current supplied to the load

35. - E7E10

How does a diode envelope detector function?

Select	Answer
A	By breakdown of the Zener voltage
B	By sensing the change of reactance in the diode with respect to frequency
C	By rectification and filtering of RF signals
D	By mixing signals with noise in the transition region of the diode

36. - E7F07

What function is performed by a Fast Fourier Transform?

Select	Answer
A	Converting digital signals from the time domain to the frequency domain
B	Converting 8-bit data to 16-bit data
C	Converting analog signals to digital form
D	Converting digital signals to analog form

37. - E7G10

What absolute voltage gain can be expected from the circuit in Figure E7-3 when R1 is 1800 ohms and RF is 68 kilohms?

Select	Answer
A	38
B	0.03
C	76
D	1

38. - E7H02

What is a microphonic?

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

39. - E8A06

What is the approximate ratio of PEP-to-average power in a typical single-sideband phone signal?

Select	Answer
A	2.5 to 1
B	25 to 1
C	100 to 1
D	1 to 1

40. - E8B07

Orthogonal Frequency Division Multiplexing is a technique used for which type of amateur communication?

Select	Answer
A	EME
B	OFDM signals are not allowed on amateur bands
C	Extremely low-power contacts
D	High-speed digital modes

41. - E8C07

What is the bandwidth of a 4800-Hz frequency shift, 9600-baud ASCII FM transmission?

Select	Answer
A	15.36 kHz
B	9.6 kHz
C	5.76 kHz
D	4.8 kHz

42. - E8D07

What is a common cause of overmodulation of AFSK signals?

Select	Answer
A	Ground loops
B	Excessive numbers of retries
C	Bit errors in the modem
D	Excessive transmit audio levels

43. - E9A01

What is an isotropic antenna?

Select	Answer
A	A horizontally polarized antenna used to compare Yagi antennas
B	A grounded antenna used to measure Earth conductivity
C	A spacecraft antenna used to direct signals toward Earth
D	A theoretical, omnidirectional antenna used as a reference for antenna gain

44. - E9B09

What type of computer program technique is commonly used for modeling antennas?

Select	Answer
A	Method of Moments
B	Calculus differentiation with respect to physical properties
C	Graphical analysis
D	Mutual impedance analysis

45. - E9C03

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

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

46. - E9D12

Which of the following would provide the best RF ground for your station?

Select	Answer
A	An electrically short connection to 3 or 4 interconnected ground rods driven into the Earth
B	An electrically short connection to a metal water pipe
C	A 50-ohm resistor connected to ground
D	An electrically short connection to 3 or 4 interconnected ground rods via a series RF choke

47. - E9E03

What is the name of the matching system that uses a section of transmission line connected in parallel with the feed line at or near the feed point?

Select	Answer
A	The delta match
B	The gamma match
C	The stub match
D	The omega match

48. - E9F09

What is the approximate physical length of a foam polyethylene dielectric coaxial transmission line that is electrically 1/4 wavelength long at 7.2 MHz?

Select	Answer
A	6.9 meters
B	8.3 meters
C	10.4 meters
D	5.2 meters

49. - E9G08

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

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

50. - E9H09

What is a Pennant antenna?

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

Figure E6-1

Figure E7-2

Figure E7-3