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 yellowish appearance of the gas
C	Any ordinary smoke detector can be used
D	By the odor

2. - E1A04

With your transceiver displaying the carrier frequency of phone signals, you hear a DX station calling CQ on 3.601 MHz LSB. Is it legal to return the call using lower sideband on the same frequency?

Select	Answer
A	No, the sideband will extend beyond the edge of the phone band segment
B	No, U.S. stations are not permitted to use phone emissions below 3.610 MHz
C	Yes, because the displayed frequency is within the 75 meter phone band segment
D	Yes, because the DX station initiated the contact

3. - E1B11

What does PRB-1 require of regulations affecting amateur radio?

Select	Answer
A	No limitations may be placed on antenna size or placement
B	Amateur radio operations must be permitted in any private residence
C	Use of wireless devices in a vehicle is exempt from regulation
D	Reasonable accommodations of amateur radio must be made

4. - E1C11

Which of the following operating arrangements allows an FCC-licensed U.S. citizen to operate in many European countries, and alien amateurs from many European countries to operate in the U.S.?

Select	Answer
A	IARP agreement
B	ITU reciprocal license
C	All these choices are correct
D	CEPT agreement

5. - E1D11

Which amateur stations are eligible to operate as Earth stations?

Select	Answer
A	Only those of Amateur Extra Class operators
B	Any amateur station, subject to the privileges of the class of operator license held by the control operator
C	Any amateur station whose licensee has filed a pre-space notification with the FCC's International Bureau
D	Only those of General, Advanced or Amateur Extra Class operators

6. - E1E02

Who does Part 97 task with maintaining the pools of questions for all U.S. amateur license examinations?

Select	Answer
A	The ARRL
B	The FCC
C	The VEs
D	The VECs

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

8. - E2A03

How is the signal inverted by an inverting linear transponder?

Select	Answer
A	The signal is passed through a non-linear filter
B	The signal is reduced to I and Q components and the Q component is filtered out
C	The signal is passed through a mixer and the difference rather than the sum is transmitted
D	The signal is detected and remodulated on the reverse sideband

9. - E2B11

What is the function of the Vertical Interval Signaling (VIS) code sent as part of an SSTV transmission?

Select	Answer
A	To identify the call sign of the station transmitting
B	To identify the SSTV mode being used
C	To provide vertical synchronization
D	To lock the color burst oscillator in color SSTV images

10. - E2C07

What is the Cabrillo format?

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

11. - E2D04

What technology is used to track, in real time, balloons carrying amateur radio transmitters?

Select	Answer
A	Doppler shift of beacon signals
B	Bandwidth compressed LORAN
C	Ultrasonics
D	APRS

12. - E2E07

Which of the following is a possible reason that attempts to initiate contact with a digital station on a clear frequency are unsuccessful?

Select	Answer
A	Your transmit frequency is incorrect
B	All these choices are correct
C	Another station you are unable to hear is using the frequency
D	The protocol version you are using is not supported by the digital station

13. - E3A09

Which of the following frequency ranges is most suited for meteor scatter communications?

Select	Answer
A	28 MHz - 148 MHz
B	10 MHz - 14 MHz
C	220 MHz - 450 MHz
D	1.8 MHz - 1.9 MHz

14. - E3B03

What is the best time of day for transequatorial propagation?

Select	Answer
A	Noon
B	Afternoon or early evening
C	Morning
D	Late at night

15. - 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	Polar
B	Transequatorial
C	Sporadic E
D	NVIS

16. - E4A10

Which of the following displays multiple digital signal states simultaneously?

Select	Answer
A	Logic analyzer
B	Network analyzer
C	Bit error rate tester
D	Modulation monitor

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

18. - E4C10

What is an advantage of having a variety of receiver IF bandwidths from which to select?

Select	Answer
A	Receive bandwidth can be set to match the modulation bandwidth, maximizing signal-to-noise ratio and minimizing interference
B	The noise figure of the RF amplifier can be adjusted to match the modulation type, thus increasing receiver sensitivity
C	Multiple frequencies can be received simultaneously if desired
D	Receiver power consumption can be reduced when wider bandwidth is not required

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	Cross-modulation interference
D	Quieting

20. - E4E11

What could cause local AM broadcast band signals to combine to generate spurious signals in the MF or HF bands?

Select	Answer
A	Your station receiver IF amplifier stage is defective
B	Nearby corroded metal joints are mixing and re-radiating the broadcast signals
C	You are receiving skywave signals from a distant station
D	One or more of the broadcast stations is transmitting an over-modulated signal

21. - E5A13

What is an effect of increasing Q in a series resonant circuit?

Select	Answer
A	Parasitic effects are minimized
B	Phase shift can become uncontrolled
C	Internal voltages increase
D	Fewer components are needed for the same performance

22. - E5B04

What is the time constant of a circuit having two 220-microfarad capacitors and two 1-megohm resistors, all in parallel?

Select	Answer
A	55 seconds
B	220 seconds
C	440 seconds
D	110 seconds

23. - 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	Elliptical coordinates
B	Polar coordinates
C	Faraday grid
D	Maidenhead grid

24. - E5D06

In what direction is the magnetic field oriented about a conductor in relation to the direction of electron flow?

Select	Answer
A	In a circle around the conductor
B	In the same direction as the current
C	In all directions; omni-directional
D	In a direction opposite to the current

25. - E6A12

Why do many MOSFET devices have internally connected Zener diodes on the gates?

Select	Answer
A	To reduce the chance of static damage to the gate
B	To keep the gate voltage within specifications and prevent the device from overheating
C	To provide a voltage reference for the correct amount of reverse-bias gate voltage
D	To protect the substrate from excessive voltages

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 VHF/UHF mixer or detector
D	As a constant voltage reference in a power supply

27. - E6C01

What is the function of hysteresis in a comparator?

Select	Answer
A	To allow the comparator to be used with AC input signals
B	To increase the sensitivity
C	To prevent input noise from causing unstable output signals
D	To cause the output to change states continually

28. - E6D03

Which of the following is an aspect of the piezoelectric effect?

Select	Answer
A	Mechanical deformation of material by the application of a magnetic field
B	Increased conductivity in the presence of light
C	Mechanical deformation of material by the application of a voltage
D	Generation of electrical energy in the presence of light

29. - E6E02

Which of the following device packages is a through-hole type?

Select	Answer
A	PLCC
B	DIP
C	SOT
D	Ball grid array

30. - E6F08

Why are optoisolators often used in conjunction with solid-state circuits when switching 120 VAC?

Select	Answer
A	Optoisolators provide a low impedance link between a control circuit and a power circuit
B	Optoisolators eliminate the effects of reflected light in the control circuit
C	Optoisolators provide a very high degree of electrical isolation between a control circuit and the circuit being switched
D	Optoisolators provide impedance matching between the control circuit and power circuit

31. - E7A04

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

Select	Answer
A	4
B	1
C	2
D	8

32. - E7B16

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

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

33. - E7C10

Which of the following filters would be the best choice for use in a 2 meter band repeater duplexer?

Select	Answer
A	An L-C filter
B	A crystal filter
C	A cavity filter
D	A DSP filter

34. - E7D14

What is the purpose of connecting equal-value resistors across power supply filter capacitors connected in series?

Select	Answer
A	All these choices are correct
B	Discharge the capacitors when voltage is removed
C	Equalize the voltage across each capacitor
D	Provide a minimum load on the supply

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. - E7F03

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

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

37. - E7G02

What is ringing in a filter?

Select	Answer
A	A reduction in high frequency response
B	Partial cancellation of the signal over a range of frequencies
C	Undesired oscillations added to the desired signal
D	An echo caused by a long time delay

38. - E7H11

What are the major spectral impurity components of direct digital synthesizers?

Select	Answer
A	Broadband noise
B	Spurious signals at discrete frequencies
C	Nyquist limit noise
D	Digital conversion noise

39. - E8A09

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

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

40. - E8B08

What describes Orthogonal Frequency Division Multiplexing?

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

41. - E8C05

What is the approximate bandwidth of a 13-WPM International Morse Code transmission?

Select	Answer
A	26 Hz
B	13 Hz
C	104 Hz
D	52 Hz

42. - E8D05

What is the most common method of reducing key clicks?

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

43. - E9A05

What is included in the total resistance of an antenna system?

Select	Answer
A	Radiation resistance plus space impedance
B	Radiation resistance plus transmission resistance
C	Transmission-line resistance plus radiation resistance
D	Radiation resistance plus loss resistance

44. - E9B07

How does the total amount of radiation emitted by a directional gain antenna compare with the total amount of radiation emitted from a theoretical isotropic antenna, assuming each is driven by the same amount of power?

Select	Answer
A	They are the same
B	The total amount of radiation from the directional antenna is stronger by its front-to-back ratio
C	The total amount of radiation from the directional antenna is increased by the gain of the antenna
D	The radiation from the isotropic antenna is 2.15 dB stronger than that from the directional antenna

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

46. - E9D02

How can linearly polarized Yagi antennas be used to produce circular polarization?

Select	Answer
A	Stack two Yagis fed in phase to form an array with the respective elements in parallel planes
B	Arrange two Yagis perpendicular to each other with the driven elements at the same point on the boom fed 90 degrees out of phase
C	Stack two Yagis fed 90 degrees out of phase to form an array with the respective elements in parallel planes
D	Arrange two Yagis collinear to each other with the driven elements fed 180 degrees out of phase

47. - E9E09

Which of the following is used to shunt-feed a grounded tower at its base?

Select	Answer
A	Gamma match
B	Hairpin match
C	All these choices are correct
D	Double-bazooka 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	10.4 meters
B	8.3 meters
C	6.9 meters
D	5.2 meters

49. - E9G09

What third family of circles is often added to a Smith chart during the process of solving problems?

Select	Answer
A	Antenna-length circles
B	Standing wave ratio circles
C	Radiation-pattern circles
D	Coaxial-length circles

50. - E9H06

What is the triangulation method of direction finding?

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