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	Polytetrafluoroethylene
B	Polyethylene
C	Polychlorinated biphenyls
D	Polymorphic silicon

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

3. - E1B03

Within what distance must an amateur station protect an FCC monitoring facility from harmful interference?

Select	Answer
A	30 miles
B	1 mile
C	3 miles
D	10 miles

4. - E1C01

What is the maximum bandwidth for a data emission on 60 meters?

Select	Answer
A	2.8 kHz
B	60 Hz
C	170 Hz
D	1.5 kHz

5. - E1D03

What is a space telecommand station?

Select	Answer
A	An amateur station that receives telemetry from a satellite or balloon more than 50 kilometers above the surface of the Earth
B	An amateur station located on the surface of the Earth for communication with other Earth stations by means of Earth satellites
C	An amateur station located in a satellite or a balloon more than 50 kilometers above the surface of the Earth
D	An amateur station that transmits communications to initiate, modify or terminate functions of a space station

6. - E1E05

What is the minimum passing score on all amateur operator license examinations?

Select	Answer
A	Minimum passing score of 74%
B	Minimum passing score of 80%
C	Minimum passing score of 70%
D	Minimum passing score of 77%

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	None, they must obtain a U.S. license
C	All privileges of the Amateur Extra Class license
D	Full privileges, up to and including those of the Amateur Extra Class license, on the 80, 40, 20, 15, and 10 meter bands

8. - E2A07

Which of the following types of signals can be relayed through a linear transponder?

Select	Answer
A	PSK and packet
B	SSB and SSTV
C	All these choices are correct
D	FM and CW

9. - E2B10

What aspect of an analog slow-scan television signal encodes the brightness of the picture?

Select	Answer
A	Tone frequency
B	Tone amplitude
C	Sync frequency
D	Sync amplitude

10. - E2C07

What is the Cabrillo format?

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

11. - E2D07

What digital protocol is used by APRS?

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

12. - E2E08

Which of the following HF digital modes can be used to transfer binary files?

Select	Answer
A	Hellschreiber
B	RTTY
C	PACTOR
D	AMTOR

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

14. - E3B12

What is the primary characteristic of chordal hop propagation?

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

15. - E3C02

What is indicated by a rising A or K index?

Select	Answer
A	An increase in the critical frequency
B	Decreasing disruption of the geomagnetic field
C	Increasing disruption of the geomagnetic field
D	Higher levels of solar UV radiation

16. - E4A09

Which of the following is good practice when using an oscilloscope probe?

Select	Answer
A	All these choices are correct
B	Never use a high-impedance probe to measure a low-impedance circuit
C	Keep the signal ground connection of the probe as short as possible
D	Never use a DC-coupled probe to measure an AC circuit

17. - E4B05

What three test loads are used to calibrate an RF vector network analyzer?

Select	Answer
A	50 ohms, 75 ohms, and 90 ohms
B	50 ohms through 1/8 wavelength, 1/4 wavelength, and 1/2 wavelength of coaxial cable
C	Short circuit, open circuit, and resonant circuit
D	Short circuit, open circuit, and 50 ohms

18. - E4C10

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

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

19. - E4D09

What is the purpose of the preselector in a communications receiver?

Select	Answer
A	To allow selection of the optimum RF amplifier device
B	To store often-used frequencies
C	To increase rejection of signals outside the desired band
D	To provide a range of AGC time constants

20. - E4E08

What current flows equally on all conductors of an unshielded multi-conductor cable?

Select	Answer
A	Common-mode current
B	Reactive current only
C	Return current
D	Differential-mode current

21. - E5A10

How is the Q of an RLC series resonant circuit calculated?

Select	Answer
A	Resistance divided by the reactance of either the inductance or capacitance
B	Reactance of the inductance multiplied by the reactance of the capacitance
C	Reactance of either the inductance or capacitance multiplied by the resistance
D	Reactance of either the inductance or capacitance divided by the resistance

22. - E5B08

What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 100 ohms, R is 100 ohms, and XL is 75 ohms?

Select	Answer
A	14 degrees with the voltage leading the current
B	76 degrees with the voltage lagging the current
C	14 degrees with the voltage lagging the current
D	76 degrees with the voltage leading the current

23. - E5C05

What is the name of the diagram used to show the phase relationship between impedances at a given frequency?

Select	Answer
A	Far field diagram
B	Venn diagram
C	Phasor diagram
D	Near field diagram

24. - E5D02

Why is it important to keep lead lengths short for components used in circuits for VHF and above?

Select	Answer
A	All these choices are correct
B	To avoid unwanted inductive reactance
C	To maintain component lifetime
D	To increase the thermal time constant

25. - E6A10

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

Select	Answer
A	5
B	6
C	2
D	4

26. - E6B02

What is an important characteristic of a Schottky diode as compared to an ordinary silicon diode when used as a power supply rectifier?

Select	Answer
A	Less forward voltage drop
B	More constant reverse avalanche voltage
C	Much higher reverse voltage breakdown
D	Longer carrier retention time

27. - E6C08

In Figure E6-3, what is the schematic symbol for a NAND gate?

Select	Answer
A	1
B	4
C	2
D	3

28. - E6D05

What is one reason for using ferrite cores rather than powdered iron in an inductor?

Select	Answer
A	Ferrite toroids are easier to use with surface mount technology
B	Ferrite toroids generally have lower initial permeability
C	Ferrite toroids generally require fewer turns to produce a given inductance value
D	Ferrite toroids generally have better temperature stability

29. - E6E03

Which of the following materials is likely to provide the highest frequency of operation when used in MMICs?

Select	Answer
A	Silicon
B	Silicon nitride
C	Silicon dioxide
D	Gallium nitride

30. - E6F06

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

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

31. - E7A11

What type of logic defines "1" as a high voltage?

Select	Answer
A	Assertive Logic
B	Positive Logic
C	Reverse Logic
D	Negative logic

32. - E7B03

Which of the following components form the output of a class D amplifier circuit?

Select	Answer
A	A high-pass filter to compensate for low gain at low frequencies
B	A low-pass filter to remove switching signal components
C	A matched load resistor to prevent damage by switching transients
D	A temperature compensating load resistor to improve linearity

33. - E7C06

What are the distinguishing features of an elliptical filter?

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

34. - E7D03

What device is typically used as a stable voltage reference in a linear voltage regulator?

Select	Answer
A	A varactor diode
B	A Zener diode
C	A tunnel diode
D	An SCR

35. - E7E02

What is the function of a reactance modulator?

Select	Answer
A	To produce PM or FM signals by using an electrically variable inductance or capacitance
B	To produce AM signals by using an electrically variable resistance
C	To produce PM signals by using an electrically variable resistance
D	To produce AM signals by using an electrically variable inductance or capacitance

36. - E7F02

What kind of digital signal processing audio filter is used to remove unwanted noise from a received SSB signal?

Select	Answer
A	A crystal-lattice filter
B	A phase-inverting filter
C	A Hilbert-transform filter
D	An adaptive filter

37. - E7G01

What is the typical output impedance of an op-amp?

Select	Answer
A	100 ohms
B	1000 ohms
C	Very high
D	Very low

38. - E7H13

Which of the following is a technique for providing highly accurate and stable oscillators needed for microwave transmission and reception?

Select	Answer
A	Use a temperature-controlled high Q dielectric resonator
B	Use a rubidium stabilized reference oscillator
C	All these choices are correct
D	Use a GPS signal reference

39. - E8A05

What of the following instruments would be the most accurate for measuring the RMS voltage of a complex waveform?

Select	Answer
A	A D'Arsonval meter
B	A true-RMS calculating meter
C	A grid dip meter
D	An absorption wave meter

40. - E8B01

What is the modulation index of an FM signal?

Select	Answer
A	The bandwidth of the transmitted signal divided by the modulating signal frequency
B	The ratio of frequency deviation to modulating signal frequency
C	The type of modulation used by the transmitter
D	The ratio of modulating signal amplitude to frequency deviation

41. - E8C03

Why should phase-shifting of a PSK signal be done at the zero crossing of the RF signal?

Select	Answer
A	To improve carrier suppression
B	All these choices are correct
C	To minimize bandwidth
D	To simplify modulation

42. - E8D09

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

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

43. - E9A10

Which of the following improves the efficiency of a ground-mounted quarter-wave vertical antenna?

Select	Answer
A	Isolating the coax shield from ground
B	All these choices are correct
C	Shortening the radiating element
D	Installing a radial system

44. - E9B09

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

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

45. - E9C11

How is the far-field elevation pattern of a vertically polarized antenna affected by being mounted over seawater versus soil?

Select	Answer
A	The low-angle radiation increases
B	The low-angle radiation decreases
C	Fewer vertical angle lobes will be present
D	Additional higher vertical angle lobes will appear

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

47. - E9E05

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

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

48. - E9F02

Which of the following has the biggest effect on the velocity factor of a transmission line?

Select	Answer
A	Dielectric materials used in the line
B	The line length
C	The center conductor resistivity
D	The termination impedance

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 antenna electrical wavelength
C	In fractions of transmission line electrical wavelength
D	In fractions of transmission line electrical frequency

50. - E9H04

What is an advantage of placing a grounded electrostatic shield around a small loop direction-finding antenna?

Select	Answer
A	It adds capacitive loading, increasing the bandwidth of the antenna
B	It increases signal strength by providing a better match to the feed line
C	It eliminates tracking errors caused by strong out-of-band signals
D	It eliminates unbalanced capacitive coupling to the surroundings, improving the nulls

Figure E6-1

Figure E6-3