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

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1. - E0A10

What toxic material may be present in some electronic components such as high voltage capacitors and transformers?

Select	Answer
A	Polychlorinated biphenyls
B	Polyethylene
C	Polymorphic silicon
D	Polytetrafluoroethylene

2. - E1A07

What is the maximum power permitted on the 2200 meter band?

Select	Answer
A	100 watts PEP
B	5 watts EIRP (Equivalent isotropic radiated power)
C	50 watts PEP
D	1 watt EIRP (Equivalent isotropic radiated power)

3. - E1B05

What is the National Radio Quiet Zone?

Select	Answer
A	An area in Puerto Rico surrounding the Arecibo Radio Telescope
B	An area surrounding the National Radio Astronomy Observatory
C	An area in Florida surrounding Cape Canaveral
D	An area in New Mexico surrounding the White Sands Test Area

4. - E1C10

What is the permitted mean power of any spurious emission relative to the mean power of the fundamental emission from a station transmitter or external RF amplifier installed after January 1, 2003 and transmitting on a frequency below 30 MHz?

Select	Answer
A	At least 43 dB below
B	At least 63 dB below
C	At least 73 dB below
D	At least 53 dB below

5. - E1D05

What must be posted at the station location of a station being operated by telecommand on or within 50 km of the earth's surface?

Select	Answer
A	A label with the name, address, and telephone number of the control operator
B	A photocopy of the station license
C	All these choices are correct
D	A label with the name, address, and telephone number of the station licensee

6. - E1E01

For which types of out-of-pocket expenses do the Part 97 rules state that VEs and VECs may be reimbursed?

Select	Answer
A	Teaching an amateur operator license examination preparation course
B	Providing amateur operator license examination preparation training materials
C	No expenses are authorized for reimbursement
D	Preparing, processing, administering, and coordinating an examination for an amateur radio operator license

7. - E1F05

Amateur stations may not transmit in which of the following frequency segments if they are located in the contiguous 48 states and north of Line A?

Select	Answer
A	222 MHz - 223 MHz
B	440 MHz - 450 MHz
C	420 MHz - 430 MHz
D	53 MHz - 54 MHz

8. - E2A01

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

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

9. - E2B12

What signals SSTV receiving software to begin a new picture line?

Select	Answer
A	Specific tone frequencies
B	A two-tone signal
C	Specific tone amplitudes
D	Elapsed time

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	A standard for submission of electronic contest logs
D	The rules of order for meetings between contest sponsors

11. - E2D07

What digital protocol is used by APRS?

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

12. - E2E04

What is indicated when one of the ellipses in an FSK crossed-ellipse display suddenly disappears?

Select	Answer
A	One of the signal filters is saturated
B	Selective fading has occurred
C	The mark and space signal have been inverted
D	The receiver has drifted 5 kHz from the desired receive frequency

13. - E3A04

What do Hepburn maps predict?

Select	Answer
A	Probability of tropospheric propagation
B	Locations of auroral reflecting zones
C	Likelihood of rain scatter along cold or warm fronts
D	Sporadic E propagation

14. - E3B02

What is the approximate maximum range for signals using transequatorial propagation?

Select	Answer
A	1000 miles
B	7500 miles
C	2500 miles
D	5000 miles

15. - E3C04

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

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

16. - E4A11

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

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

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

18. - E4C08

An SDR receiver is overloaded when input signals exceed what level?

Select	Answer
A	One-half the maximum sample rate
B	The maximum count value of the analog-to-digital converter
C	The reference voltage of the analog-to-digital converter
D	One-half the maximum sampling buffer size

19. - E4D11

Why are odd-order intermodulation products, created within a receiver, of particular interest compared to other products?

Select	Answer
A	Odd-order products of two signals in the band of interest are also likely to be within the band
B	Odd-order products overload the IF filters
C	Odd-order intermodulation produces three products for every input signal within the band of interest
D	Odd-order products are an indication of poor image rejection

20. - E4E03

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

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

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

22. - E5B07

What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 500 ohms, R is 1 kilohm, and XL is 250 ohms?

Select	Answer
A	14.0 degrees with the voltage leading the current
B	14.0 degrees with the voltage lagging the current
C	68.2 degrees with the voltage lagging the current
D	68.2 degrees with the voltage leading the current

23. - E5C07

Where is the impedance of a pure resistance plotted on rectangular coordinates?

Select	Answer
A	On a horizontal line, offset vertically above the horizontal axis
B	On the horizontal axis
C	On a line through the origin, slanted at 45 degrees
D	On the vertical axis

24. - E5D05

What is the power factor of an RL circuit having a 30-degree phase angle between the voltage and the current?

Select	Answer
A	1.73
B	0.5
C	0.866
D	0.577

25. - E6A10

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

Select	Answer
A	6
B	2
C	4
D	5

26. - E6B07

What is the failure mechanism when a junction diode fails due to excessive current?

Select	Answer
A	Excessive junction temperature
B	Excessive inverse voltage
C	Insufficient forward voltage
D	Charge carrier depletion

27. - E6C10

In Figure E6-3, what is the schematic symbol for a NOR gate?

Select	Answer
A	1
B	2
C	3
D	4

28. - E6D01

Why should core saturation of an impedance matching transformer be avoided?

Select	Answer
A	Temporary changes of the core permeability could result
B	Harmonics and distortion could result
C	Magnetic flux would increase with frequency
D	RF susceptance would increase

29. - E6E12

Why are DIP through-hole package ICs not typically used at UHF and higher frequencies?

Select	Answer
A	Excessive lead length
B	Epoxy coating is conductive above 300 MHz
C	Unsuitable for combining analog and digital signals
D	Too many pins

30. - E6F04

What is the photovoltaic effect?

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

31. - E7A04

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

Select	Answer
A	1
B	2
C	4
D	8

32. - E7B02

What is a Class D amplifier?

Select	Answer
A	A frequency doubling amplifier
B	An amplifier that uses drift-mode FETs for high efficiency
C	A type of amplifier that uses switching technology to achieve high efficiency
D	A low power amplifier that uses a differential amplifier for improved linearity

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 inductors are in series between the input and output, and a capacitor is connected between the two inductors 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	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
D	Two capacitors are in series between the input and output, and an inductor is connected between the two capacitors and ground

34. - E7D08

What type of circuit is shown in Figure E7-2?

Select	Answer
A	Switching voltage regulator
B	Monostable multivibrator
C	Grounded emitter amplifier
D	Linear voltage regulator

35. - E7E05

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

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

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 notches out the sampling frequency to avoid sampling errors
C	It peaks the response of the decimator, improving bandwidth
D	It removes high-frequency signal components that would otherwise be reproduced as lower frequency components

37. - E7G07

What magnitude of voltage gain can be expected from the circuit in Figure E73 when R1 is 10 ohms and RF is 470 ohms?

Select	Answer
A	0.21
B	94
C	47
D	24

38. - E7H14

What is a phase-locked loop circuit?

Select	Answer
A	An electronic circuit also known as a monostable multivibrator
B	An electronic servo loop consisting of a ratio detector, reactance modulator, and voltage-controlled oscillator
C	An electronic servo loop consisting of a phase detector, a low-pass filter, a voltage-controlled oscillator, and a stable reference oscillator
D	An electronic circuit consisting of a precision push-pull amplifier with a differential input

39. - E8A09

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

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

40. - E8B06

What is the deviation ratio of an FM-phone signal having a maximum frequency swing of plus or minus 7.5 kHz when the maximum modulation frequency is 3.5 kHz?

Select	Answer
A	2.14
B	47
C	0.214
D	0.47

41. - E8C10

How may data rate be increased without increasing bandwidth?

Select	Answer
A	Increasing analog-to-digital conversion resolution
B	Using forward error correction
C	It is impossible
D	Using a more efficient digital code

42. - E8D07

What is a common cause of overmodulation of AFSK signals?

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

43. - E9A11

Which of the following factors determines ground losses for a ground-mounted vertical antenna operating in the 3 MHz to 30 MHz range?

Select	Answer
A	Take-off angle
B	The standing wave ratio
C	Soil conductivity
D	Distance from the transmitter

44. - E9B11

What is a disadvantage of decreasing the number of wire segments in an antenna model below 10 segments per half-wavelength?

Select	Answer
A	The antenna will become mechanically unstable
B	The resulting design will favor radiation of harmonic energy
C	The computed feed point impedance may be incorrect
D	Ground conductivity will not be accurately modeled

45. - E9C08

What is a folded dipole antenna?

Select	Answer
A	A dipole configured to provide forward gain
B	A dipole one-quarter wavelength long
C	A half-wave dipole with an additional parallel wire connecting its two ends
D	A type of ground-plane antenna

46. - E9D03

Where should a high Q loading coil be placed to minimize losses in a shortened vertical antenna?

Select	Answer
A	As close to the transmitter as possible
B	At a voltage node
C	As low as possible on the vertical radiator
D	Near the center of the vertical radiator

47. - E9E01

What system matches a higher-impedance transmission line to a lower-impedance antenna by connecting the line to the driven element in two places spaced a fraction of a wavelength each side of element center?

Select	Answer
A	The gamma matching system
B	The omega matching system
C	The delta matching system
D	The stub matching system

48. - E9F08

Which of the following is a significant difference between foam dielectric coaxial cable and solid dielectric cable, assuming all other parameters are the same?

Select	Answer
A	Foam dielectric has lower loss per unit of length
B	Foam dielectric has higher velocity factor
C	All these choices are correct
D	Foam dielectric has lower safe operating voltage limits

49. - E9G11

How are the wavelength scales on a Smith chart calibrated?

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

50. - E9H02

Which is generally true for low band (160 meter and 80 meter) receiving antennas?

Select	Answer
A	Low loss coax transmission line is essential for good performance
B	All these choices are correct
C	They must be erected at least 1/2 wavelength above the ground to attain good directivity
D	Atmospheric noise is so high that gain over a dipole is not important

Figure E6-1

Figure E6-3

Figure E7-2