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

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1. - E0A04

When evaluating a site with multiple transmitters operating at the same time, the operators and licensees of which transmitters are responsible for mitigating over-exposure situations?

Select	Answer
A	Only the most powerful transmitter
B	Only commercial transmitters
C	Each transmitter operating with a duty cycle greater than 50 percent
D	Each transmitter that produces 5 percent or more of its MPE limit in areas where the total MPE limit is exceeded.

2. - E1A01

Which of the following carrier frequencies is illegal for LSB AFSK emissions on the 17 meter band RTTY and data segment of 18.068 to 18.110 MHz?

Select	Answer
A	18.068 MHz
B	18.107 MHz
C	18.100 MHz
D	18.110 MHz

3. - E1B11

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

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

4. - E1C12

On what portion of the 630 meter band are phone emissions permitted?

Select	Answer
A	None
B	Only the bottom 3 kHz
C	The entire band
D	Only the top 3 kHz

5. - E1D01

What is the definition of telemetry?

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

6. - E1E04

Which of the following best describes the Volunteer Examiner accreditation process?

Select	Answer
A	The prospective VE obtains accreditation from the FCC
B	Each General, Advanced and Amateur Extra Class operator is automatically accredited as a VE when the license is granted
C	The amateur operator applying must pass a VE examination administered by the FCC Enforcement Bureau
D	The procedure by which a VEC confirms that the VE applicant meets FCC requirements to serve as an examiner

7. - E1F08

Which of the following types of amateur station communications are prohibited?

Select	Answer
A	Communications transmitted for hire or material compensation, except as otherwise provided in the rules
B	Communications in a language other than English
C	Communications that have religious content
D	Communications that have political content, except as allowed by the Fairness Doctrine

8. - E2A03

How is the signal inverted by an inverting linear transponder?

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

9. - E2B06

What is vestigial sideband modulation?

Select	Answer
A	Narrow-band FM modulation achieved by filtering one sideband from the audio before frequency modulating the carrier
B	Spread spectrum modulation achieved by applying FM modulation following single sideband amplitude modulation
C	A type of modulation in which one sideband is inverted
D	Amplitude modulation in which one complete sideband and a portion of the other are transmitted

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 run a net to allow many stations to contact a rare DX station
C	To allocate frequencies for DXpeditions
D	To relay calls to and from a DX station

11. - E2D04

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

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

12. - E2E13

Which of these digital modes has the fastest data throughput under clear communication conditions?

Select	Answer
A	300 baud packet
B	170 Hz shift, 45 baud RTTY
C	AMTOR
D	PSK31

13. - E3A08

When a meteor strikes the Earth's atmosphere, a cylindrical region of free electrons is formed at what layer of the ionosphere?

Select	Answer
A	The E layer
B	The D layer
C	The F2 layer
D	The F1 layer

14. - E3B04

What is meant by the terms "extraordinary" and "ordinary" waves?

Select	Answer
A	Long-path and short-path waves
B	Extraordinary waves describe rare long-skip propagation compared to ordinary waves, which travel shorter distances
C	Refracted rays and reflected waves
D	Independent waves created in the ionosphere that are elliptically polarized

15. - E3C14

Why does the radio-path horizon distance exceed the geometric horizon?

Select	Answer
A	Due to the Doppler effect
B	Downward bending due to density variations in the atmosphere
C	E-region skip
D	D-region skip

16. - E4A11

How should an antenna analyzer be connected when measuring antenna resonance and feed point impedance?

Select	Answer
A	Connect the analyzer via a high-impedance transformer to the antenna
B	Loosely couple the analyzer near the antenna base
C	Connect the antenna feed line directly to the analyzer's connector
D	Loosely couple the antenna and a dummy load to the analyzer

17. - E4B02

What is the significance of voltmeter sensitivity expressed in ohms per volt?

Select	Answer
A	When used as a galvanometer, the reading in volts multiplied by the ohms per volt rating will determine the power drawn by the device under test
B	When used as an ohmmeter, the reading in ohms divided by the ohms per volt rating will determine the voltage applied to the circuit
C	When used as an ammeter, the full scale reading in amps divided by ohms per volt rating will determine the size of shunt needed
D	The full scale reading of the voltmeter multiplied by its ohms per volt rating will indicate the input impedance of the voltmeter

18. - E4C03

What is the term for the suppression in an FM receiver of one signal by another stronger signal on the same frequency?

Select	Answer
A	Desensitization
B	Frequency discrimination
C	Cross-modulation interference
D	Capture effect

19. - E4D07

Which of the following reduces the likelihood of receiver desensitization?

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

20. - E4E10

What might be the cause of a loud roaring or buzzing AC line interference that comes and goes at intervals?

Select	Answer
A	A malfunctioning illuminated advertising display
B	A defective doorbell or doorbell transformer inside a nearby residence
C	All these choices are correct
D	Arcing contacts in a thermostatically controlled device

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

22. - E5B09

What is the relationship between the AC current through a capacitor and the voltage across a capacitor?

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

23. - E5C11

Which point in Figure E5-1 best represents the impedance of a series circuit consisting of a 300-ohm resistor and an 18-microhenry inductor at 3.505 MHz?

Select	Answer
A	Point 1
B	Point 7
C	Point 3
D	Point 8

24. - E5D10

How can the true power be determined in an AC circuit where the voltage and current are out of phase?

Select	Answer
A	By dividing the apparent power by the power factor
B	By dividing the reactive power by the power factor
C	By multiplying the reactive power by the power factor
D	By multiplying the apparent power by the power factor

25. - E6A05

How does DC input impedance at the gate of a field-effect transistor compare with the DC input impedance of a bipolar transistor?

Select	Answer
A	An FET has higher input impedance
B	They are both low impedance
C	An FET has lower input impedance
D	They are both high impedance

26. - E6B04

What type of semiconductor device is designed for use as a voltage-controlled capacitor?

Select	Answer
A	Silicon-controlled rectifier
B	Varactor diode
C	Tunnel diode
D	Zener diode

27. - E6C09

What is a Programmable Logic Device (PLD)?

Select	Answer
A	A logic circuit that can be modified during use
B	A type of transistor whose gain can be changed by digital logic circuits
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. - E6D12

What is inductor saturation?

Select	Answer
A	The ability of the inductor's core to store magnetic energy has been exceeded
B	The inductor's voltage rating is exceeded causing a flashover
C	Adjacent inductors become over-coupled
D	The inductor windings are over-coupled

29. - E6E08

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

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

30. - E6F02

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

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

31. - E7A10

What is a truth table?

Select	Answer
A	A list of inputs and corresponding outputs for a digital device
B	A diagram showing logic states when the digital device output is true
C	A table of logic symbols that indicate the logic states of an op-amp
D	A table of logic symbols that indicate the high logic states of an op-amp

32. - E7B16

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

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

33. - E7C04

How does an impedance-matching circuit transform a complex impedance to a resistive impedance?

Select	Answer
A	It introduces transconductance to cancel the reactive part of impedance
B	It cancels the reactive part of the impedance and changes the resistive part to a desired value
C	Reactive currents are dissipated in matched resistances
D	It introduces negative resistance to cancel the resistive part of impedance

34. - E7D12

What is the dropout voltage of an analog voltage regulator?

Select	Answer
A	Maximum that the output voltage may decrease at rated load
B	Minimum input voltage for rated power dissipation
C	Maximum output voltage drops when the input voltage is varied over its specified range
D	Minimum input-to-output voltage required to maintain regulation

35. - E7E05

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

Select	Answer
A	A heterodyne enhancer
B	A de-emphasis network
C	A pre-emphasis network
D	A heterodyne suppressor

36. - E7F08

What is the function of decimation?

Select	Answer
A	Removing unnecessary significant digits
B	Converting data to binary code decimal form
C	Attenuating the signal
D	Reducing the effective sample rate by removing samples

37. - E7G04

What is meant by the "op-amp input offset voltage"?

Select	Answer
A	The potential between the amplifier input terminals of the op-amp in an open loop condition
B	The differential input voltage needed to bring the open loop output voltage to zero
C	The difference between the output voltage of the op-amp and the input voltage required in the immediately following stage
D	The output voltage of the op-amp minus its input voltage

38. - E7H08

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

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

39. - E8A02

Which of the following is a type of analog-to-digital conversion?

Select	Answer
A	Phase reversal
B	Successive approximation
C	Harmonic regeneration
D	Level shifting

40. - E8B02

How does the modulation index of a phase-modulated emission vary with RF carrier frequency?

Select	Answer
A	It varies with the square root of the RF carrier frequency
B	It does not depend on the RF carrier frequency
C	It increases as the RF carrier frequency increases
D	It decreases as the RF carrier frequency increases

41. - E8C06

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

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

42. - E8D04

What is the primary effect of extremely short rise or fall time on a CW signal?

Select	Answer
A	The generation of key clicks
B	The generation of RF harmonics
C	Limits data speed
D	More difficult to copy

43. - E9A07

What is the effective isotropic radiated power of a repeater station with 200 watts transmitter power output, 2 dB feed line loss, 2.8 dB duplexer loss, 1.2 dB circulator loss, and 7 dBi antenna gain?

Select	Answer
A	252 watts
B	632 watts
C	159 watts
D	63.2 watts

44. - E9B04

What is the front-to-back ratio of the radiation pattern shown in Figure E92?

Select	Answer
A	3 dB
B	15 dB
C	38 dB
D	28 dB

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

46. - E9D09

What is the function of a loading coil used as part of an HF mobile antenna?

Select	Answer
A	To lower the Q
B	To lower the losses
C	To cancel capacitive reactance
D	To increase the SWR bandwidth

47. - E9E02

What is the name of an antenna matching system that matches an unbalanced feed line to an antenna by feeding the driven element both at the center of the element and at a fraction of a wavelength to one side of center?

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

48. - E9F06

What is the approximate physical length of an air-insulated, parallel conductor transmission line that is electrically 1/2 wavelength long at 14.10 MHz?

Select	Answer
A	8.5 meters
B	13.3 meters
C	7.0 meters
D	10.6 meters

49. - E9G11

How are the wavelength scales on a Smith chart calibrated?

Select	Answer
A	In fractions of antenna electrical frequency
B	In fractions of transmission line electrical wavelength
C	In fractions of transmission line electrical frequency
D	In fractions of antenna electrical wavelength

50. - E9H05

What is the main drawback of a small wire-loop antenna for direction finding?

Select	Answer
A	It is practical for use only on VHF and higher bands
B	All these choices are correct
C	It has a bidirectional pattern
D	It has no clearly defined null

Figure E5-1