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	By the yellowish appearance of the gas
B	Only with a carbon monoxide detector
C	By the odor
D	Any ordinary smoke detector can be used

2. - E1A10

If an amateur station is installed aboard a ship or aircraft, what condition must be met before the station is operated?

Select	Answer
A	Its operation must be approved by the master of the ship or the pilot in command of the aircraft
B	The amateur station must have a power supply that is completely independent of the main ship or aircraft power supply
C	The amateur operator must have an FCC Marine or Aircraft endorsement on his or her amateur license
D	The amateur station operator must agree not to transmit when the main radio of the ship or aircraft is in use

3. - E1B06

Which of the following additional rules apply if you are installing an amateur station antenna at a site at or near a public use airport?

Select	Answer
A	You may have to notify the Federal Aviation Administration and register it with the FCC as required by Part 17 of the FCC rules
B	You must file an Environmental Impact Statement with the EPA before construction begins
C	You must obtain a construction permit from the airport zoning authority
D	You must submit engineering drawings to the FAA

4. - E1C02

Which of the following types of communications may be transmitted to amateur stations in foreign countries?

Select	Answer
A	Messages intended for users of the maritime satellite service
B	All these choices are correct
C	Business-related messages for non-profit organizations
D	Communications incidental to the purpose of the amateur service and remarks of a personal nature

5. - E1D09

Which UHF amateur bands have frequencies authorized for space stations?

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

6. - E1E03

What is a Volunteer Examiner Coordinator?

Select	Answer
A	The person who has entered into an agreement with the FCC to be the VE session manager
B	An organization that has entered into an agreement with the FCC to coordinate, prepare, and administer amateur operator license examinations
C	A person who has volunteered to administer amateur operator license examinations
D	A person who has volunteered to prepare amateur operator license examinations

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	None, they must obtain a U.S. license
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	The operating terms and conditions of the Canadian amateur service license, not to exceed U.S. Amateur Extra Class license privileges
D	All privileges of the Amateur Extra Class license

8. - E2A01

What is the direction of an ascending pass for an amateur satellite?

Select	Answer
A	From west to east
B	From north to south
C	From south to north
D	From east to west

9. - E2B08

What technique allows commercial analog TV receivers to be used for fast-scan TV operations on the 70 cm band?

Select	Answer
A	Using USB and demodulating the signal with a computer sound card
B	Transmitting on the abandoned TV channel 2
C	Using converted satellite TV dishes
D	Transmitting on channels shared with cable TV

10. - E2C10

Why might a DX station state that they are listening on another frequency?

Select	Answer
A	Because the DX station may be transmitting on a frequency that is prohibited to some responding stations
B	To improve operating efficiency by reducing interference
C	All these choices are correct
D	To separate the calling stations from the DX station

11. - E2D04

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

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

12. - E2E01

Which of the following types of modulation is common for data emissions below 30 MHz?

Select	Answer
A	Spread spectrum
B	DTMF tones modulating an FM signal
C	FSK
D	Pulse modulation

13. - E3A02

What characterizes libration fading of an EME signal?

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

14. - E3B12

What is the primary characteristic of chordal hop propagation?

Select	Answer
A	Signals reflected back toward the transmitting station
B	Successive ionospheric refractions without an intermediate reflection from the ground
C	Propagation away from the great circle bearing between stations
D	Propagation across the geomagnetic equator

15. - E3C01

What does the radio communication term "ray tracing" describe?

Select	Answer
A	Determining the radiation pattern from an array of antennas
B	The process in which an electronic display presents a pattern
C	Evaluating high voltage sources for x-rays
D	Modeling a radio wave's path through the ionosphere

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	A false, jittery low-frequency version of the signal is displayed
D	Calibration of the vertical scale is no longer valid

17. - E4B10

Which of the following methods measures intermodulation distortion in an SSB transmitter?

Select	Answer
A	Modulate the transmitter using two RF signals having harmonically related frequencies and observe the RF output with a logic analyzer
B	Modulate the transmitter using two AF signals having non-harmonically related frequencies and observe the RF output with a spectrum analyzer
C	Modulate the transmitter using two RF signals having non-harmonically related frequencies and observe the RF output with a spectrum analyzer
D	Modulate the transmitter using two AF signals having harmonically related frequencies and observe the RF output with a peak reading wattmeter

18. - E4C13

How does a narrow-band roofing filter affect receiver performance?

Select	Answer
A	It improves intelligibility by using low Q circuitry to reduce ringing
B	It improves dynamic range by attenuating strong signals near the receive frequency
C	All these choices are correct
D	It improves sensitivity by reducing front end noise

19. - E4D05

What transmitter frequencies would cause an intermodulation-product signal in a receiver tuned to 146.70 MHz when a nearby station transmits on 146.52 MHz?

Select	Answer
A	146.88 MHz and 146.34 MHz
B	146.10 MHz and 147.30 MHz
C	173.35 MHz and 139.40 MHz
D	146.34 MHz and 146.61 MHz

20. - E4E03

Which of the following signals might a receiver noise blanker be able to remove from desired signals?

Select	Answer
A	Signals that have a sharply peaked frequency distribution
B	Signals that appear across a wide bandwidth
C	Signals that appear at one IF but not another
D	Signals that are constant at all IF levels

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 leads the current by 90 degrees
D	The voltage and current are 180 degrees out of phase

22. - E5B06

What is susceptance?

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

23. - E5C04

What coordinate system is often used to display the resistive, inductive, and/or capacitive reactance components of impedance?

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

24. - E5D14

What is reactive power?

Select	Answer
A	Power consumed in wire resistance in an inductor
B	Power consumed in circuit Q
C	Wattless, nonproductive power
D	Power lost because of capacitor leakage

25. - E6A10

In Figure E6-1, what is the schematic symbol for an N-channel dual-gate MOSFET?

Select	Answer
A	4
B	2
C	5
D	6

26. - E6B11

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

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

27. - E6C09

What is a Programmable Logic Device (PLD)?

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

28. - E6D07

What is current in the primary winding of a transformer called if no load is attached to the secondary?

Select	Answer
A	Direct current
B	Excitation current
C	Magnetizing current
D	Stabilizing current

29. - E6E08

How is power supplied to the most common type of MMIC?

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

30. - E6F06

Which of these materials is most commonly used to create photoconductive devices?

Select	Answer
A	A liquid semiconductor
B	A heavy metal
C	An ordinary metal
D	A crystalline semiconductor

31. - E7A09

What logical operation is performed by an exclusive NOR gate?

Select	Answer
A	It produces logic 0 at its output if only one input is logic 1
B	It produces logic 1 at its output only if all inputs are logic 1
C	It produces logic 1 at its output if only one input is logic 1
D	It produces logic 0 at its output only if all inputs are logic 0

32. - E7B14

Why are switching amplifiers more efficient than linear amplifiers?

Select	Answer
A	Linear amplifiers have high gain resulting in higher harmonic content
B	Switching amplifiers use push-pull circuits
C	The power transistor is at saturation or cutoff most of the time
D	Switching amplifiers operate at higher voltages

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

34. - E7D13

What is the equation for calculating power dissipated by a series linear voltage regulator?

Select	Answer
A	Output voltage multiplied by output current
B	Input voltage divided by output current
C	Voltage difference from input to output multiplied by output current
D	Input voltage multiplied by input current

35. - E7E03

What is a frequency discriminator stage in a FM receiver?

Select	Answer
A	An automatic band-switching circuit
B	An FM generator circuit
C	A circuit for filtering two closely adjacent signals
D	A circuit for detecting FM signals

36. - E7F09

Why is an anti-aliasing digital filter required in a digital decimator?

Select	Answer
A	It removes low-frequency signal components to eliminate the need for DC restoration
B	It peaks the response of the decimator, improving bandwidth
C	It notches out the sampling frequency to avoid sampling errors
D	It removes high-frequency signal components that would otherwise be reproduced as lower frequency components

37. - E7G02

What is ringing in a filter?

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

38. - E7H10

What information is contained in the lookup table of a direct digital synthesizer (DDS)?

Select	Answer
A	Amplitude values that represent the desired waveform
B	Frequently used receiver and transmitter frequencies
C	The phase relationship between a reference oscillator and the output waveform
D	The phase relationship between a voltage-controlled oscillator and the output waveform

39. - E8A10

What is the purpose of a low-pass filter used in conjunction with a digital-to-analog converter?

Select	Answer
A	Remove harmonics from the output caused by the discrete analog levels generated
B	Improve accuracy by removing out-of-sequence codes from the input
C	Lower the input bandwidth to increase the effective resolution
D	All these choices are correct

40. - E8B04

What is the modulation index of an FM-phone signal having a maximum carrier deviation of plus or minus 6 kHz when modulated with a 2 kHz modulating frequency?

Select	Answer
A	1/3
B	2000
C	3
D	6000

41. - E8C06

What is the bandwidth of a 170-hertz shift, 300-baud ASCII transmission?

Select	Answer
A	1.0 kHz
B	0.1 Hz
C	0.3 kHz
D	0.5 kHz

42. - E8D09

What is considered an acceptable maximum IMD level for an idling PSK signal?

Select	Answer
A	+15 dB
B	+10 dB
C	-20 dB
D	-30 dB

43. - E9A04

Which of the following factors affect the feed point impedance of an antenna?

Select	Answer
A	Transmission line length
B	Antenna height
C	The input power level
D	The settings of an antenna tuner at the transmitter

44. - E9B09

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

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

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

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	A 50-ohm resistor connected to ground
C	An electrically short connection to 3 or 4 interconnected ground rods via a series RF choke
D	An electrically short connection to a metal water pipe

47. - E9E05

How must an antenna's driven element be tuned to use a hairpin matching system?

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

48. - E9F10

What impedance does a 1/8-wavelength transmission line present to a generator when the line is shorted at the far end?

Select	Answer
A	A capacitive reactance
B	Zero
C	An inductive reactance
D	The same as the characteristic impedance of the line

49. - E9G03

Which of the following is often determined using a Smith chart?

Select	Answer
A	Satellite azimuth and elevation bearings
B	Beam headings and radiation patterns
C	Impedance and SWR values in transmission lines
D	Trigonometric functions

50. - E9H03

What is Receiving Directivity Factor (RDF)?

Select	Answer
A	Forward gain compared to average gain over the entire hemisphere
B	Relative directivity compared to isotropic
C	Forward gain compared to the gain in the reverse direction
D	Relative directivity compared to a dipole

Figure E6-1