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

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1. - E0A05

What is one of the potential hazards of operating in the amateur radio microwave bands?

Select	Answer
A	The extremely high frequency energy can damage the joints of antenna structures
B	Microwaves often travel long distances by ionospheric reflection
C	The high gain antennas commonly used can result in high exposure levels
D	Microwaves are ionizing radiation

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	They are restricted to phone band segments
C	None; they are allowed on all amateur frequencies
D	They are restricted to 7.245 MHz, 14.245 MHz, 21.345 MHz, and 28.945 MHz

3. - E1B09

Which amateur stations may be operated under RACES rules?

Select	Answer
A	Any FCC-licensed amateur station participating in the Military Auxiliary Radio System (MARS)
B	Any FCC-licensed amateur station except a Technician Class
C	Any FCC-licensed amateur station certified by the responsible civil defense organization for the area served
D	Only those club stations licensed to Amateur Extra Class operators

4. - E1C05

When may an automatically controlled station originate third party communications?

Select	Answer
A	When approved by the National Telecommunication and Information Administration
B	Only when transmitting RTTY or data emissions
C	Never
D	When agreed upon by the sending or receiving station

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

6. - E1E08

To which of the following examinees may a VE not administer an examination?

Select	Answer
A	Relatives of the VE as listed in the FCC rules
B	Friends of the VE
C	Employees of the VE
D	All these choices are correct

7. - E1F10

Who may be the control operator of an auxiliary station?

Select	Answer
A	Only Amateur Extra Class operators
B	Only General, Advanced or Amateur Extra Class operators
C	Only Technician, General, Advanced or Amateur Extra Class operators
D	Any licensed amateur operator

8. - E2A13

Which of the following techniques is normally used by low Earth orbiting digital satellites to relay messages around the world?

Select	Answer
A	Store-and-forward
B	Node hopping
C	Multi-satellite relaying
D	Digipeating

9. - E2B01

How many times per second is a new frame transmitted in a fast-scan (NTSC) television system?

Select	Answer
A	120
B	90
C	30
D	60

10. - E2C08

Which of the following contacts may be confirmed through the U.S. QSL bureau system?

Select	Answer
A	Repeater contacts between U.S. club members
B	Contacts using tactical call signs
C	Special event contacts between stations in the U.S.
D	Contacts between a U.S. station and a non-U.S. station

11. - E2D04

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

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

12. - E2E02

What do the letters FEC mean as they relate to digital operation?

Select	Answer
A	Fatal Error Correction
B	Forward Error Correction
C	Final Error Correction
D	First Error Correction

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

14. - E3B06

Which of the following amateur bands most frequently provides long-path propagation?

Select	Answer
A	6 meters
B	20 meters
C	80 meters
D	10 meters

15. - E3C13

What type of polarization is best for ground-wave propagation?

Select	Answer
A	Horizontal
B	Vertical
C	Elliptical
D	Circular

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. - E4B08

Which of the following can be used to measure the Q of a series-tuned circuit?

Select	Answer
A	The frequency shift
B	The resonant frequency of the circuit
C	The inductance to capacitance ratio
D	The bandwidth of the circuit's frequency response

18. - E4C02

Which of the following receiver circuits can be effective in eliminating interference from strong out-of-band signals?

Select	Answer
A	A notch filter
B	A narrow IF filter
C	A front-end filter or pre-selector
D	A properly adjusted product detector

19. - E4D08

What causes intermodulation in an electronic circuit?

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

20. - E4E05

How can radio frequency interference from an AC motor be suppressed?

Select	Answer
A	By installing a brute-force AC-line filter in series with the motor leads
B	By installing a bypass capacitor in series with the motor leads
C	By installing a high-pass filter in series with the motor's power leads
D	By using a ground-fault current interrupter in the circuit used to power the motor

21. - E5A09

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

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

22. - E5B12

What is admittance?

Select	Answer
A	The term for the gain of a field effect transistor
B	The inverse of Q factor
C	The inverse of impedance
D	The turns ratio of a transformer

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 8
D	Point 3

24. - E5D07

How many watts are consumed in a circuit having a power factor of 0.71 if the apparent power is 500VA?

Select	Answer
A	1.42 mW
B	704 W
C	355 W
D	252 W

25. - E6A04

What is the name given to an impurity atom that adds holes to a semiconductor crystal structure?

Select	Answer
A	Insulator impurity
B	Donor impurity
C	Acceptor impurity
D	N-type impurity

26. - E6B10

In Figure E6-2, what is the schematic symbol for a light-emitting diode?

Select	Answer
A	6
B	7
C	5
D	1

27. - E6C05

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

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

28. - E6D13

What is the primary cause of inductor self-resonance?

Select	Answer
A	Non-linear core hysteresis
B	Inductive kickback
C	Inter-turn capacitance
D	The skin effect

29. - E6E09

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

Select	Answer
A	Axial lead
B	Surface mount
C	TO-220
D	Radial 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. - 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 only produces logic 0 at its output when all inputs are logic 1
C	It produces logic 0 at its output if all inputs are logic 1
D	It produces logic 1 at its output if any or all inputs are logic 1

32. - E7B06

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

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

33. - E7C12

What is one advantage of a Pi-matching network over an L-matching network consisting of a single inductor and a single capacitor?

Select	Answer
A	Pi-networks provide balanced input and output
B	The Q of Pi-networks can be controlled
C	Pi-networks are more stable
D	L-networks cannot perform impedance transformation

34. - E7D14

What is the purpose of connecting equal-value resistors across power supply filter capacitors connected in series?

Select	Answer
A	Equalize the voltage across each capacitor
B	Provide a minimum load on the supply
C	All these choices are correct
D	Discharge the capacitors when voltage is removed

35. - E7E03

What is a frequency discriminator stage in a FM receiver?

Select	Answer
A	A circuit for detecting FM signals
B	An FM generator circuit
C	An automatic band-switching circuit
D	A circuit for filtering two closely adjacent signals

36. - E7F05

How frequently must an analog signal be sampled by an analog-to-digital converter so that the signal can be accurately reproduced?

Select	Answer
A	At least twice the rate of the highest frequency component of the signal
B	At least half the rate of the highest frequency component of the signal
C	At the same rate as the highest frequency component of the signal
D	At four times the rate of the highest frequency component of the signal

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	A digital audio amplifier whose characteristics are determined by components external to the amplifier
D	An amplifier used to increase the average output of frequency modulated amateur signals to the legal limit

38. - E7H08

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

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

39. - E8A01

What is the name of the process that shows that a square wave is made up of a sine wave plus all its odd harmonics?

Select	Answer
A	Differential analysis
B	Vector analysis
C	Numerical analysis
D	Fourier analysis

40. - E8B04

What is the modulation index of an FM-phone signal having a maximum carrier deviation of plus or minus 6 kHz when modulated with a 2 kHz modulating frequency?

Select	Answer
A	3
B	6000
C	1/3
D	2000

41. - E8C12

What factors affect the bandwidth of a transmitted CW signal?

Select	Answer
A	Keying speed and shape factor (rise and fall time)
B	Modulation index and output power
C	IF bandwidth and Q
D	All these choices are correct

42. - E8D01

Why are received spread spectrum signals resistant to interference?

Select	Answer
A	The high power used by a spread spectrum transmitter keeps its signal from being easily overpowered
B	If interference is detected by the receiver it will signal the transmitter to change frequencies
C	Signals not using the spread spectrum algorithm are suppressed in the receiver
D	The receiver is always equipped with a digital blanker

43. - E9A05

What is included in the total resistance of an antenna system?

Select	Answer
A	Radiation resistance plus loss resistance
B	Transmission-line resistance plus radiation resistance
C	Radiation resistance plus transmission resistance
D	Radiation resistance plus space impedance

44. - E9B05

What type of antenna pattern is shown in Figure E9-2?

Select	Answer
A	Elevation
B	Radiation resistance
C	Polarization
D	Azimuth

45. - E9C10

Which of the following describes a Zepp antenna?

Select	Answer
A	A vertical array capable of quickly changing the direction of maximum radiation by changing phasing lines
B	A dipole constructed from zip cord
C	An end-fed dipole antenna
D	An omni-directional antenna commonly used for satellite communications

46. - E9D08

What happens as the Q of an antenna increases?

Select	Answer
A	More common-mode current is present on the feed line
B	Gain is reduced
C	SWR bandwidth decreases
D	SWR bandwidth increases

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 stub matching system
D	The delta matching system

48. - E9F12

What impedance does a 1/4-wavelength transmission line present to a generator when the line is open at the far end?

Select	Answer
A	Very high impedance
B	The same as the characteristic impedance of the line
C	Very low impedance
D	The same as the input impedance to the generator

49. - E9G06

On the Smith chart shown in Figure E9-3, what is the name for the large outer circle on which the reactance arcs terminate?

Select	Answer
A	Impedance axis
B	Reactance axis
C	Prime axis
D	Polar axis

50. - E9H09

What is a Pennant antenna?

Select	Answer
A	A small, vertically oriented receiving antenna consisting of a triangular loop terminated in approximately 900 ohms
B	A four-element, high-gain vertical array invented by George Pennant
C	A form of rhombic antenna terminated in a variable capacitor to provide frequency diversity
D	A stealth antenna built to look like a flagpole

Figure E5-1

Figure E6-2

Figure E9-2

Figure E9-3