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

2. - E1A12

What special operating frequency restrictions are imposed on slow scan TV transmissions?

Select	Answer
A	They are not permitted above 54 MHz
B	None; they are allowed on all amateur frequencies
C	They are restricted to phone band segments
D	They are restricted to 7.245 MHz, 14.245 MHz, 21.345 MHz, and 28.945 MHz

3. - E1B02

Which of the following is an acceptable bandwidth for Digital Radio Mondiale (DRM) based voice or SSTV digital transmissions made on the HF amateur bands?

Select	Answer
A	15 kHz
B	10 kHz
C	20 kHz
D	3 kHz

4. - E1C13

What notifications must be given before transmitting on the 630 meter or 2200 meter bands?

Select	Answer
A	Operators must inform the Utilities Technology Council (UTC) of their call sign and coordinates of the station
B	An environmental impact statement must be filed with the Department of the Interior
C	A special endorsement must be requested from the FCC
D	Operators must inform the FAA of their intent to operate, giving their call sign and distance to the nearest runway

5. - E1D07

Which HF amateur bands have frequencies authorized for space stations?

Select	Answer
A	Only the 40, 30, 20, 15, 12, and 10 meter bands
B	Only the 40, 20, 17, 15, 12, and 10 meter bands
C	All HF bands
D	Only the 40, 20, 17, 15, and 10 meter bands

6. - E1E12

What must the VE team do with the application form if the examinee does not pass the exam?

Select	Answer
A	Return the application document to the examinee
B	Maintain the application form with the VEC's records
C	Send the application form to the FCC and inform the FCC of the grade
D	Destroy the application form

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	The operating terms and conditions of the Canadian amateur service license, not to exceed U.S. Amateur Extra Class license privileges
C	Full privileges, up to and including those of the Amateur Extra Class license, on the 80, 40, 20, 15, and 10 meter bands
D	All privileges of the Amateur Extra Class license

8. - E2A09

What do the terms L band and S band specify regarding satellite communications?

Select	Answer
A	The 23 centimeter and 13 centimeter bands
B	FM and Digital Store-and-Forward systems
C	The 2 meter and 70 centimeter bands
D	Which sideband to use

9. - E2B03

How is an interlaced scanning pattern generated in a fast-scan (NTSC) television system?

Select	Answer
A	By scanning each field from bottom to top
B	By scanning odd numbered lines in one field and even numbered lines in the next
C	By scanning two fields simultaneously
D	By scanning lines from left to right in one field and right to left in the next

10. - E2C03

From which of the following bands is amateur radio contesting generally excluded?

Select	Answer
A	2 meters
B	30 meters
C	6 meters
D	33 centimeters

11. - E2D02

Which of the following is a good technique for making meteor scatter contacts?

Select	Answer
A	15-second timed transmission sequences with stations alternating based on location
B	Use of special digital modes
C	All these choices are correct
D	Short transmissions with rapidly repeated call signs and signal reports

12. - E2E08

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

Select	Answer
A	PACTOR
B	RTTY
C	AMTOR
D	Hellschreiber

13. - E3A12

What is the cause of auroral activity?

Select	Answer
A	An extreme low-pressure area in the polar regions
B	The interaction in the E layer of charged particles from the Sun with the Earth's magnetic field
C	The interaction in the F2 layer between the solar wind and the Van Allen belt
D	Meteor showers concentrated in the extreme northern and southern latitudes

14. - E3B05

Which amateur bands typically support long-path propagation?

Select	Answer
A	160 meters to 10 meters
B	6 meters to 2 meters
C	Only 30 meters to 10 meters
D	Only 160 meters to 40 meters

15. - E3C03

Which of the following signal paths is most likely to experience high levels of absorption when the A index or K index is elevated?

Select	Answer
A	NVIS
B	Polar
C	Transequatorial
D	Sporadic E

16. - E4A10

Which of the following displays multiple digital signal states simultaneously?

Select	Answer
A	Bit error rate tester
B	Logic analyzer
C	Network analyzer
D	Modulation monitor

17. - E4B04

Which S parameter represents input port return loss or reflection coefficient (equivalent to VSWR)?

Select	Answer
A	S12
B	S21
C	S11
D	S22

18. - E4C04

What is the noise figure of a receiver?

Select	Answer
A	The ratio of thermal noise to atmospheric noise
B	The ratio in dB of the noise generated by the receiver to the theoretical minimum noise
C	The ratio of the noise bandwidth in hertz to the theoretical bandwidth of a resistive network
D	The ratio of atmospheric noise to phase noise

19. - E4D03

How can intermodulation interference between two repeaters occur?

Select	Answer
A	When the signals from the transmitters are reflected out of phase from airplanes passing overhead
B	When the repeaters are in close proximity and the signals mix in the final amplifier of one or both transmitters
C	When the repeaters are in close proximity and the signals cause feedback in the final amplifier of one or both transmitters
D	When the signals from the transmitters are reflected in phase from airplanes passing overhead

20. - E4E09

What undesirable effect can occur when using an IF noise blanker?

Select	Answer
A	Nearby signals may appear to be excessively wide even if they meet emission standards
B	Received audio in the speech range might have an echo effect
C	The audio frequency bandwidth of the received signal might be compressed
D	FM signals can no longer be demodulated

21. - E5A14

What is the resonant frequency of an RLC circuit if R is 22 ohms, L is 50 microhenries and C is 40 picofarads?

Select	Answer
A	3.56 MHz
B	22.36 MHz
C	1.78 MHz
D	44.72 MHz

22. - E5B09

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

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

23. - E5C02

How are impedances described in polar coordinates?

Select	Answer
A	By X and R values
B	By Y and G values
C	By phase angle and magnitude
D	By real and imaginary parts

24. - E5D09

What happens to reactive power in an AC circuit that has both ideal inductors and ideal capacitors?

Select	Answer
A	It is dissipated as kinetic energy in the circuit
B	It is dissipated in the formation of inductive and capacitive fields
C	It is repeatedly exchanged between the associated magnetic and electric fields, but is not dissipated
D	It is dissipated as heat in the circuit

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

26. - E6B01

What is the most useful characteristic of a Zener diode?

Select	Answer
A	A constant current drop under conditions of varying voltage
B	A negative resistance region
C	An internal capacitance that varies with the applied voltage
D	A constant voltage drop under conditions of varying current

27. - E6C11

In Figure E6-3, what is the schematic symbol for the NOT operation (inverter)?

Select	Answer
A	6
B	5
C	2
D	4

28. - E6D10

What is a primary advantage of using a toroidal core instead of a solenoidal core in an inductor?

Select	Answer
A	Toroidal cores confine most of the magnetic field within the core material
B	Toroidal cores have lower Q characteristics
C	Toroidal cores exhibit greater hysteresis
D	Toroidal cores make it easier to couple the magnetic energy into other components

29. - E6E11

What is a characteristic of DIP packaging used for integrated circuits?

Select	Answer
A	Two chips in each package (Dual In Package)
B	Package mounts in a direct inverted position
C	A total of two rows of connecting pins placed on opposite sides of the package (Dual In-line Package)
D	Low leakage doubly insulated package

30. - E6F10

What is the most common type of photovoltaic cell used for electrical power generation?

Select	Answer
A	Silicon
B	Copper oxide
C	Selenium
D	Cadmium Sulfide

31. - E7A07

What logical operation does a NAND gate perform?

Select	Answer
A	It produces logic 0 at its output only when all inputs are logic 0
B	It produces logic 1 at its output only when all inputs are logic 1
C	It produces logic 0 at its output if some but not all inputs are logic 1
D	It produces logic 0 at its output only when all inputs are logic 1

32. - E7B16

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

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

33. - E7C11

Which of the following describes a receiving filter's ability to reject signals occupying an adjacent channel?

Select	Answer
A	Phase response
B	Shape factor
C	Passband ripple
D	Noise factor

34. - E7D01

How does a linear electronic voltage regulator work?

Select	Answer
A	The control element duty cycle is proportional to the line or load conditions
B	It eliminates the need for a pass transistor
C	The conduction of a control element is varied to maintain a constant output voltage
D	It has a ramp voltage as its output

35. - E7E06

Why is de-emphasis commonly used in FM communications receivers?

Select	Answer
A	For higher efficiency
B	To remove third-order distortion products
C	For compatibility with transmitters using phase modulation
D	To reduce impulse noise reception

36. - E7F06

What is the minimum number of bits required for an analog-to-digital converter to sample a signal with a range of 1 volt at a resolution of 1 millivolt?

Select	Answer
A	4 bits
B	8 bits
C	10 bits
D	6 bits

37. - E7G04

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

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

38. - E7H12

Which of the following must be done to ensure that a crystal oscillator provides the frequency specified by the crystal manufacturer?

Select	Answer
A	Provide the crystal with a specified parallel inductance
B	Bias the crystal at a specified voltage
C	Bias the crystal at a specified current
D	Provide the crystal with a specified parallel capacitance

39. - E8A03

What type of wave does a Fourier analysis show to be made up of sine waves of a given fundamental frequency plus all its harmonics?

Select	Answer
A	A square wave
B	A sine wave
C	A cosine wave
D	A sawtooth wave

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 type of modulation used by the transmitter
C	The ratio of frequency deviation to modulating signal frequency
D	The ratio of modulating signal amplitude to frequency deviation

41. - E8C02

What is the definition of symbol rate in a digital transmission?

Select	Answer
A	The rate at which the waveform changes to convey information
B	The duration of each bit in a message sent over the air
C	The number of control characters in a message packet
D	The number of characters carried per second by the station-to-station link

42. - E8D05

What is the most common method of reducing key clicks?

Select	Answer
A	Increase keying waveform rise and fall times
B	Low-pass filters at the transmitter output
C	High-pass filters at the transmitter output
D	Reduce keying waveform rise and fall times

43. - E9A10

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

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

44. - E9B02

In the antenna radiation pattern shown in Figure E9-1, what is the front-to-back ratio?

Select	Answer
A	14 dB
B	18 dB
C	36 dB
D	24 dB

45. - E9C06

What is the effect of adding a terminating resistor to a rhombic antenna?

Select	Answer
A	It reflects the standing waves on the antenna elements back to the transmitter
B	It decreases the ground loss
C	It changes the radiation pattern from bidirectional to unidirectional
D	It changes the radiation pattern from horizontal to vertical polarization

46. - E9D11

Which of the following conductors would be best for minimizing losses in a station's RF ground system?

Select	Answer
A	Resistive wire, such as spark plug wire
B	Wide flat copper strap
C	Stranded wire
D	Solid wire

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

48. - E9F11

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

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

49. - E9G02

What type of coordinate system is used in a Smith chart?

Select	Answer
A	Voltage circles and current arcs
B	Resistance circles and reactance arcs
C	Resistance lines and reactance chords
D	Voltage lines and current chords

50. - E9H04

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

Select	Answer
A	It eliminates unbalanced capacitive coupling to the surroundings, improving the nulls
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 adds capacitive loading, increasing the bandwidth of the antenna

Figure E6-3

Figure E9-1