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

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1. - E0A11

Which of the following injuries can result from using high-power UHF or microwave transmitters?

Select	Answer
A	Hearing loss caused by high voltage corona discharge
B	Ingestion of ozone gas from the cooling system
C	Localized heating of the body from RF exposure in excess of the MPE limits
D	Blood clotting from the intense magnetic field

2. - E1A02

When using a transceiver that displays the carrier frequency of phone signals, which of the following displayed frequencies represents the lowest frequency at which a properly adjusted LSB emission will be totally within the band?

Select	Answer
A	The exact lower band edge
B	3 kHz above the lower band edge
C	1 kHz above the lower band edge
D	300 Hz above the lower band edge

3. - 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 Historic Places?

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

4. - E1C12

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

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

5. - E1D08

Which VHF amateur bands have frequencies authorized for space stations?

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

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	A person who has volunteered to administer amateur operator license examinations
C	An organization that has entered into an agreement with the FCC to coordinate, prepare, and administer amateur operator license examinations
D	A person who has volunteered to prepare amateur operator license examinations

7. - E1F07

When may an amateur station send a message to a business?

Select	Answer
A	When the total money involved does not exceed $25
B	When neither the amateur nor his or her employer has a pecuniary interest in the communications
C	When the control operator is employed by the FCC or another government agency
D	When transmitting international third-party communications

8. - E2A11

What type of antenna can be used to minimize the effects of spin modulation and Faraday rotation?

Select	Answer
A	A linearly polarized antenna
B	A log-periodic dipole array
C	A circularly polarized antenna
D	An isotropic antenna

9. - E2B02

How many horizontal lines make up a fast-scan (NTSC) television frame?

Select	Answer
A	1080
B	525
C	30
D	60

10. - E2C06

During a VHF/UHF contest, in which band segment would you expect to find the highest level of SSB or CW activity?

Select	Answer
A	At the top of each band, usually in a segment reserved for contests
B	In the middle of each band, usually on the national calling frequency
C	In the weak signal segment of the band, with most of the activity near the calling frequency
D	In the middle of the band, usually 25 kHz above the national calling frequency

11. - E2D04

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

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

12. - E2E12

How do ALE stations establish contact?

Select	Answer
A	ALE radios activate when they hear their signal echoed by back scatter
B	ALE radios monitor an internet site for the frequency they are being paged on
C	ALE radios send a constant tone code to establish a frequency for future use
D	ALE constantly scans a list of frequencies, activating the radio when the designated call sign is received

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

14. - E3B07

What happens to linearly polarized radio waves that split into ordinary and extraordinary waves in the ionosphere?

Select	Answer
A	They become phase locked
B	They become elliptically polarized
C	They are bent toward the magnetic poles
D	They become depolarized

15. - E3C04

What does the value of Bz (B sub Z) represent?

Select	Answer
A	Direction and strength of the interplanetary magnetic field
B	Geomagnetic field stability
C	Duration of long-delayed echoes
D	Critical frequency for vertical transmissions

16. - E4A06

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

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

17. - E4B03

Which S parameter is equivalent to forward gain?

Select	Answer
A	S22
B	S12
C	S21
D	S11

18. - E4C05

What does a receiver noise floor of -174 dBm represent?

Select	Answer
A	The minimum detectable signal as a function of receive frequency
B	The noise figure of a 1 Hz bandwidth receiver
C	The galactic noise contribution to minimum detectable signal
D	The theoretical noise in a 1 Hz bandwidth at the input of a perfect receiver at room temperature

19. - E4D08

What causes intermodulation in an electronic circuit?

Select	Answer
A	Nonlinear circuits or devices
B	Too little gain
C	Lack of neutralization
D	Positive feedback

20. - E4E04

How can conducted and radiated noise caused by an automobile alternator be suppressed?

Select	Answer
A	By connecting the radio's power leads directly to the battery and by installing coaxial capacitors in line with the alternator leads
B	By installing filter capacitors in series with the DC power lead and a blocking capacitor in the field lead
C	By installing a noise suppression resistor and a blocking capacitor in both leads
D	By installing a high-pass filter in series with the radio's power lead and a low-pass filter in parallel with the field lead

21. - E5A11

What is the half-power bandwidth of a resonant circuit that has a resonant frequency of 7.1 MHz and a Q of 150?

Select	Answer
A	23.67 kHz
B	315.6 Hz
C	47.3 kHz
D	157.8 Hz

22. - E5B10

What is the relationship between the AC current through an inductor and the voltage across an inductor?

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

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 3
B	Point 1
C	Point 8
D	Point 7

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

25. - E6A09

What is a depletion-mode FET?

Select	Answer
A	An FET that has no current flow between source and drain when no gate voltage is applied
B	Any FET for which holes are the majority carriers
C	Any FET without a channel
D	An FET that exhibits a current flow between source and drain when no gate voltage is applied

26. - E6B06

Which of the following is a common use of a Schottky diode?

Select	Answer
A	As a variable capacitance in an automatic frequency control circuit
B	As a constant voltage reference in a power supply
C	As a rectifier in high current power supplies
D	As a VHF/UHF mixer or detector

27. - E6C05

What is an advantage of CMOS logic devices over TTL devices?

Select	Answer
A	Immune to damage from static discharge
B	Lower power consumption
C	Differential output capability
D	Lower distortion

28. - E6D09

What devices are commonly used as VHF and UHF parasitic suppressors at the input and output terminals of a transistor HF amplifier?

Select	Answer
A	Electrolytic capacitors
B	Ferrite beads
C	Butterworth filters
D	Steel-core toroids

29. - E6E09

Which of the following component package types would be most suitable for use at frequencies above the HF range?

Select	Answer
A	Radial lead
B	TO-220
C	Axial lead
D	Surface mount

30. - E6F04

What is the photovoltaic effect?

Select	Answer
A	The tendency of a battery to discharge when exposed to light
B	The conversion of voltage to current when exposed to light
C	The conversion of electrical energy to mechanical energy
D	The conversion of light to electrical energy

31. - E7A08

What logical operation does an OR gate perform?

Select	Answer
A	It produces logic 1 at its output if all inputs are logic 0
B	It produces logic 1 at its output if any or all inputs are logic 1
C	It produces logic 0 at its output if all inputs are logic 1
D	It only produces logic 0 at its output when all inputs are logic 1

32. - E7B06

Which of the following amplifier types reduces even-order harmonics?

Select	Answer
A	Class AB
B	Push-pull
C	Class C
D	Push-push

33. - E7C06

What are the distinguishing features of an elliptical filter?

Select	Answer
A	Gradual passband rolloff with minimal stop band ripple
B	Gradual passband rolloff with extreme stop band ripple
C	Extremely flat response over its pass band with gradually rounded stop band corners
D	Extremely sharp cutoff with one or more notches in the stop band

34. - E7D06

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

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

35. - E7E08

What are the principal frequencies that appear at the output of a mixer circuit?

Select	Answer
A	The two input frequencies along with their sum and difference frequencies
B	The square root of the product of input frequencies
C	Two and four times the original frequency
D	1.414 and 0.707 times the input frequency

36. - E7F10

What aspect of receiver analog-to-digital conversion determines the maximum receive bandwidth of a Direct Digital Conversion SDR?

Select	Answer
A	Sample clock phase noise
B	Sample rate
C	Processor latency
D	Sample width in bits

37. - E7G12

What is an operational amplifier?

Select	Answer
A	A high-gain, direct-coupled differential amplifier with very high input impedance and very low output impedance
B	A RF amplifier used in the UHF and microwave regions
C	An amplifier used to increase the average output of frequency modulated amateur signals to the legal limit
D	A digital audio amplifier whose characteristics are determined by components external to the amplifier

38. - E7H04

How is positive feedback supplied in a Colpitts oscillator?

Select	Answer
A	Through link coupling
B	Through a neutralizing capacitor
C	Through a capacitive divider
D	Through a tapped coil

39. - E8A02

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

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

40. - E8B07

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

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

41. - E8C06

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

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

42. - E8D09

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

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

43. - E9A03

What is the radiation resistance of an antenna?

Select	Answer
A	The value of a resistance that would dissipate the same amount of power as that radiated from an antenna
B	The specific impedance of the antenna
C	The resistance in the atmosphere that an antenna must overcome to be able to radiate a signal
D	The combined losses of the antenna elements and feed line

44. - E9B10

What is the principle of a Method of Moments analysis?

Select	Answer
A	A wire is modeled as a series of segments, each having a uniform value of current
B	A wire is modeled as a single sine-wave current generator
C	A wire is modeled as a single sine-wave voltage source
D	A wire is modeled as a series of segments, each having a distinct value of voltage across it

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

46. - E9D04

Why should an HF mobile antenna loading coil have a high ratio of reactance to resistance?

Select	Answer
A	To minimize the Q
B	To lower the radiation angle
C	To swamp out harmonics
D	To minimize losses

47. - E9E06

Which of these feed line impedances would be suitable for constructing a quarter-wave Q-section for matching a 100-ohm loop to 50-ohm feed line?

Select	Answer
A	62 ohms
B	50 ohms
C	450 ohms
D	75 ohms

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	7.0 meters
B	10.6 meters
C	8.5 meters
D	13.3 meters

49. - E9G11

How are the wavelength scales on a Smith chart calibrated?

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

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 E5-1

Figure E7-2