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

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1. - E0A09

Which insulating material commonly used as a thermal conductor for some types of electronic devices is extremely toxic if broken or crushed and the particles are accidentally inhaled?

Select	Answer
A	Uranium Hexafluoride
B	Beryllium Oxide
C	Mica
D	Zinc oxide

2. - E1A04

With your transceiver displaying the carrier frequency of phone signals, you hear a DX station calling CQ on 3.601 MHz LSB. Is it legal to return the call using lower sideband on the same frequency?

Select	Answer
A	No, the sideband will extend beyond the edge of the phone band segment
B	Yes, because the displayed frequency is within the 75 meter phone band segment
C	Yes, because the DX station initiated the contact
D	No, U.S. stations are not permitted to use phone emissions below 3.610 MHz

3. - E1B07

To what type of regulations does PRB-1 apply?

Select	Answer
A	FAA tower height limits
B	Homeowners associations
C	State and local zoning
D	Use of wireless devices in vehicles

4. - E1C08

What is the maximum permissible duration of a remotely controlled station's transmissions if its control link malfunctions?

Select	Answer
A	5 minutes
B	3 minutes
C	30 seconds
D	10 minutes

5. - E1D09

Which UHF amateur bands have frequencies authorized for space stations?

Select	Answer
A	70 cm and 13 cm
B	70 cm and 33 cm
C	33 cm and 13 cm
D	70 cm only

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

7. - E1F03

Under what circumstances may a dealer sell an external RF power amplifier capable of operation below 144 MHz if it has not been granted FCC certification?

Select	Answer
A	It was imported from a manufacturer in a country that does not require certification of RF power amplifiers
B	The equipment dealer assembled it from a kit
C	It was purchased in used condition from an amateur operator and is sold to another amateur operator for use at that operator's station
D	It was imported from a manufacturer in another country and was certificated by that country's government

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	Multi-satellite relaying
C	Digipeating
D	Node hopping

9. - E2B03

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

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

10. - E2C03

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

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

11. - E2D07

What digital protocol is used by APRS?

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

12. - E2E13

Which of these digital modes has the fastest data throughput under clear communication conditions?

Select	Answer
A	170 Hz shift, 45 baud RTTY
B	AMTOR
C	PSK31
D	300 baud packet

13. - E3A02

What characterizes libration fading of an EME signal?

Select	Answer
A	A slow change in the pitch of the CW signal
B	A gradual loss of signal as the sun rises
C	A fluttery irregular fading
D	The returning echo is several hertz lower in frequency than the transmitted signal

14. - E3B03

What is the best time of day for transequatorial propagation?

Select	Answer
A	Afternoon or early evening
B	Morning
C	Late at night
D	Noon

15. - E3C09

How does the intensity of an X3 flare compare to that of an X2 flare?

Select	Answer
A	Four times as great
B	10 percent greater
C	50 percent greater
D	Twice as great

16. - E4A08

Which of the following measures SWR?

Select	Answer
A	An antenna analyzer
B	A Q meter
C	An ohmmeter
D	A spectrum analyzer

17. - E4B02

What is the significance of voltmeter sensitivity expressed in ohms per volt?

Select	Answer
A	When used as a galvanometer, the reading in volts multiplied by the ohms per volt rating will determine the power drawn by the device under test
B	When used as an ammeter, the full scale reading in amps divided by ohms per volt rating will determine the size of shunt needed
C	When used as an ohmmeter, the reading in ohms divided by the ohms per volt rating will determine the voltage applied to the circuit
D	The full scale reading of the voltmeter multiplied by its ohms per volt rating will indicate the input impedance of the voltmeter

18. - E4C06

A CW receiver with the AGC off has an equivalent input noise power density of -174 dBm/Hz. What would be the level of an unmodulated carrier input to this receiver that would yield an audio output SNR of 0 dB in a 400 Hz noise bandwidth?

Select	Answer
A	-164 dBm
B	-155 dBm
C	-148 dBm
D	-174 dBm

19. - E4D04

Which of the following may reduce or eliminate intermodulation interference in a repeater caused by another transmitter operating in close proximity?

Select	Answer
A	A properly terminated circulator at the output of the repeater's transmitter
B	Utilizing a Class D final amplifier
C	A band-pass filter in the feed line between the transmitter and receiver
D	Utilizing a Class C final amplifier

20. - E4E11

What could cause local AM broadcast band signals to combine to generate spurious signals in the MF or HF bands?

Select	Answer
A	One or more of the broadcast stations is transmitting an over-modulated signal
B	Your station receiver IF amplifier stage is defective
C	Nearby corroded metal joints are mixing and re-radiating the broadcast signals
D	You are receiving skywave signals from a distant station

21. - E5A05

What is the result of increasing the Q of an impedance-matching circuit?

Select	Answer
A	It has no effect on impedance matching
B	Matching range is increased
C	Matching bandwidth is increased
D	Matching bandwidth is decreased

22. - E5B05

What happens to the magnitude of a pure reactance when it is converted to a susceptance?

Select	Answer
A	It is shifted by 90 degrees
B	It is unchanged
C	The sign is reversed
D	It becomes the reciprocal

23. - E5C01

Which of the following represents capacitive reactance in rectangular notation?

Select	Answer
A	Delta
B	Omega
C	+jX
D	-jX

24. - E5D10

How can the true power be determined in an AC circuit where the voltage and current are out of phase?

Select	Answer
A	By dividing the apparent power by the power factor
B	By multiplying the reactive power by the power factor
C	By multiplying the apparent power by the power factor
D	By dividing the reactive power by the power factor

25. - E6A08

What term indicates the frequency at which the grounded-base current gain of a transistor has decreased to 0.7 of the gain obtainable at 1 kHz?

Select	Answer
A	Alpha rejection frequency
B	Beta cutoff frequency
C	Corner frequency
D	Alpha cutoff frequency

26. - E6B06

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

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

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. - E6D13

What is the primary cause of inductor self-resonance?

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

29. - E6E07

What type of transmission line is used for connections to MMICs?

Select	Answer
A	Circular waveguide
B	Parallel wire
C	Miniature coax
D	Microstrip

30. - E6F10

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

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

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

32. - E7B08

How can an RF power amplifier be neutralized?

Select	Answer
A	By feeding a 180-degree out-of-phase portion of the output back to the input
B	By feeding an in-phase component of the output back to the input
C	By reducing the driving power
D	By increasing the driving power

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

34. - E7D14

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

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

35. - E7E01

Which of the following can be used to generate FM phone emissions?

Select	Answer
A	A reactance modulator on the oscillator
B	A balanced modulator on the oscillator
C	A reactance modulator on the final amplifier
D	A balanced modulator on the audio amplifier

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 half the rate of the highest frequency component of the signal
B	At four times 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 least twice the rate of the highest frequency component of the signal

37. - E7G10

What absolute voltage gain can be expected from the circuit in Figure E7-3 when R1 is 1800 ohms and RF is 68 kilohms?

Select	Answer
A	76
B	0.03
C	1
D	38

38. - E7H15

Which of these functions can be performed by a phase-locked loop?

Select	Answer
A	Comparison of two digital input signals, digital pulse counter
B	Frequency synthesis, FM demodulation
C	Photovoltaic conversion, optical coupling
D	Wide-band AF and RF power amplification

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

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	47
B	0.47
C	0.214
D	2.14

41. - E8C07

What is the bandwidth of a 4800-Hz frequency shift, 9600-baud ASCII FM transmission?

Select	Answer
A	9.6 kHz
B	5.76 kHz
C	15.36 kHz
D	4.8 kHz

42. - E8D04

What is the primary effect of extremely short rise or fall time on a CW signal?

Select	Answer
A	Limits data speed
B	The generation of RF harmonics
C	More difficult to copy
D	The generation of key clicks

43. - E9A05

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

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

44. - E9B02

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

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

45. - E9C08

What is a folded dipole antenna?

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

46. - E9D11

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

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

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	75 ohms
D	450 ohms

48. - E9F03

Why is the physical length of a coaxial cable transmission line shorter than its electrical length?

Select	Answer
A	Skin effect is less pronounced in the coaxial cable
B	The characteristic impedance is higher in a parallel feed line
C	The surge impedance is higher in a parallel feed line
D	Electrical signals move more slowly in a coaxial cable than in air

49. - E9G04

What are the two families of circles and arcs that make up a Smith chart?

Select	Answer
A	Resistance and reactance
B	Resistance and voltage
C	Reactance and voltage
D	Voltage and impedance

50. - E9H03

What is Receiving Directivity Factor (RDF)?

Select	Answer
A	Relative directivity compared to a dipole
B	Relative directivity compared to isotropic
C	Forward gain compared to average gain over the entire hemisphere
D	Forward gain compared to the gain in the reverse direction

Figure E6-3

Figure E7-3

Figure E9-1