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

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1. - E0A06

Why are there separate electric (E) and magnetic (H) field MPE limits?

Select	Answer
A	E field and H field radiation intensity peaks can occur at different locations
B	Ground reflections and scattering make the field strength vary with location
C	The body reacts to electromagnetic radiation from both the E and H fields
D	All these choices are correct

2. - E1A01

Which of the following carrier frequencies is illegal for LSB AFSK emissions on the 17 meter band RTTY and data segment of 18.068 to 18.110 MHz?

Select	Answer
A	18.068 MHz
B	18.100 MHz
C	18.107 MHz
D	18.110 MHz

3. - E1B09

Which amateur stations may be operated under RACES rules?

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

4. - E1C01

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

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

5. - E1D01

What is the definition of telemetry?

Select	Answer
A	One-way transmission that initiates, modifies, or terminates the functions of a device at a distance
B	Two-way transmissions in excess of 1000 feet
C	Two-way transmissions of data
D	One-way transmission of measurements at a distance from the measuring instrument

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 70%
C	Minimum passing score of 77%
D	Minimum passing score of 80%

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

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

9. - E2B11

What is the function of the Vertical Interval Signaling (VIS) code sent as part of an SSTV transmission?

Select	Answer
A	To lock the color burst oscillator in color SSTV images
B	To provide vertical synchronization
C	To identify the call sign of the station transmitting
D	To identify the SSTV mode being used

10. - E2C04

Which of the following frequencies are sometimes used for amateur radio mesh networks?

Select	Answer
A	Cable TV channels 41 through 43
B	HF frequencies where digital communications are permitted
C	Frequencies shared with various unlicensed wireless data services
D	The 60 meter band channel centered on 5373 kHz

11. - E2D02

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

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

12. - E2E13

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

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

13. - E3A05

Tropospheric propagation of microwave signals often occurs in association with what phenomenon?

Select	Answer
A	Lightning discharges
B	Warm and cold fronts
C	Sprites and jets
D	Grayline

14. - E3B06

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

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

15. - E3C13

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

Select	Answer
A	Elliptical
B	Vertical
C	Circular
D	Horizontal

16. - E4A01

Which of the following limits the highest frequency signal that can be accurately displayed on a digital oscilloscope?

Select	Answer
A	Amount of memory
B	All these choices are correct
C	Sampling rate of the analog-to-digital converter
D	Q of the circuit

17. - E4B11

Which of the following can be measured with a vector network analyzer?

Select	Answer
A	Output impedance
B	All these choices are correct
C	Input impedance
D	Reflection coefficient

18. - E4C07

What does the MDS of a receiver represent?

Select	Answer
A	The meter display sensitivity
B	The multiplex distortion stability
C	The minimum discernible signal
D	The maximum detectable spectrum

19. - E4D05

What transmitter frequencies would cause an intermodulation-product signal in a receiver tuned to 146.70 MHz when a nearby station transmits on 146.52 MHz?

Select	Answer
A	146.34 MHz and 146.61 MHz
B	146.10 MHz and 147.30 MHz
C	146.88 MHz and 146.34 MHz
D	173.35 MHz and 139.40 MHz

20. - E4E10

What might be the cause of a loud roaring or buzzing AC line interference that comes and goes at intervals?

Select	Answer
A	All these choices are correct
B	A defective doorbell or doorbell transformer inside a nearby residence
C	Arcing contacts in a thermostatically controlled device
D	A malfunctioning illuminated advertising display

21. - E5A11

What is the half-power bandwidth of a resonant circuit that has a resonant frequency of 7.1 MHz and a Q of 150?

Select	Answer
A	47.3 kHz
B	315.6 Hz
C	23.67 kHz
D	157.8 Hz

22. - E5B06

What is susceptance?

Select	Answer
A	The ratio of magnetic field to electric field
B	The magnetic impedance of a circuit
C	The imaginary part of admittance
D	A measure of the efficiency of a transformer

23. - E5C09

When using rectangular coordinates to graph the impedance of a circuit, what do the axes represent?

Select	Answer
A	The X axis represents the magnitude and the Y axis represents the phase angle
B	The X axis represents the reactive component and the Y axis represents the resistive component
C	The X axis represents the phase angle and the Y axis represents the magnitude
D	The X axis represents the resistive component and the Y axis represents the reactive component

24. - E5D14

What is reactive power?

Select	Answer
A	Wattless, nonproductive power
B	Power lost because of capacitor leakage
C	Power consumed in circuit Q
D	Power consumed in wire resistance in an inductor

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	N-type impurity
C	Donor impurity
D	Acceptor impurity

26. - E6B06

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

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

27. - E6C03

What is tri-state logic?

Select	Answer
A	Low-power logic devices designed to operate at 3 volts
B	Proprietary logic devices manufactured by Tri-State Devices
C	Logic devices with 0, 1, and high-impedance output states
D	Logic devices that utilize ternary math

28. - E6D05

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

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

29. - E6E10

What advantage does surface-mount technology offer at RF compared to using through-hole components?

Select	Answer
A	All these choices are correct
B	Components have less parasitic inductance and capacitance
C	Smaller circuit area
D	Shorter circuit-board traces

30. - E6F06

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

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

31. - E7A10

What is a truth table?

Select	Answer
A	A list of inputs and corresponding outputs for a digital device
B	A diagram showing logic states when the digital device output is true
C	A table of logic symbols that indicate the high logic states of an op-amp
D	A table of logic symbols that indicate the logic states of an op-amp

32. - E7B13

Which of the following describes an emitter follower (or common collector) amplifier?

Select	Answer
A	An OR circuit with only one emitter used for output
B	A differential amplifier with both inputs fed to the emitter of the input transistor
C	A two-transistor amplifier with the emitters sharing a common bias resistor
D	An amplifier with a low impedance output that follows the base input voltage

33. - E7C06

What are the distinguishing features of an elliptical filter?

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

34. - E7D08

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

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

35. - E7E08

What are the principal frequencies that appear at the output of a mixer circuit?

Select	Answer
A	1.414 and 0.707 times the input frequency
B	Two and four times the original frequency
C	The two input frequencies along with their sum and difference frequencies
D	The square root of the product of input frequencies

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

37. - E7G02

What is ringing in a filter?

Select	Answer
A	A reduction in high frequency response
B	An echo caused by a long time delay
C	Undesired oscillations added to the desired signal
D	Partial cancellation of the signal over a range of frequencies

38. - E7H02

What is a microphonic?

Select	Answer
A	Distortion caused by RF pickup on the microphone cable
B	Changes in oscillator frequency due to mechanical vibration
C	An IC used for amplifying microphone signals
D	Excess loading of the microphone by an oscillator

39. - E8A02

Which of the following is a type of analog-to-digital conversion?

Select	Answer
A	Phase reversal
B	Harmonic regeneration
C	Level shifting
D	Successive approximation

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	0.47
B	47
C	0.214
D	2.14

41. - E8C05

What is the approximate bandwidth of a 13-WPM International Morse Code transmission?

Select	Answer
A	26 Hz
B	52 Hz
C	104 Hz
D	13 Hz

42. - E8D03

How does the spread spectrum technique of frequency hopping work?

Select	Answer
A	If interference is detected by the receiver it will signal the transmitter to wait until the frequency is clear
B	A binary bit stream is used to shift the phase of an RF carrier very rapidly in a pseudorandom sequence
C	The frequency of the transmitted signal is changed very rapidly according to a pseudorandom sequence also used by the receiving station
D	If interference is detected by the receiver it will signal the transmitter to change frequencies

43. - E9A02

What is the effective radiated power relative to a dipole of a repeater station with 150 watts transmitter power output, 2 dB feed line loss, 2.2 dB duplexer loss, and 7 dBd antenna gain?

Select	Answer
A	286 watts
B	78.7 watts
C	420 watts
D	1977 watts

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

45. - E9C01

What is the radiation pattern of two 1/4-wavelength vertical antennas spaced 1/2-wavelength apart and fed 180 degrees out of phase?

Select	Answer
A	Omni-directional
B	Cardioid
C	A figure-8 oriented along the axis of the array
D	A figure-8 broadside to the axis of the array

46. - E9D02

How can linearly polarized Yagi antennas be used to produce circular polarization?

Select	Answer
A	Arrange two Yagis collinear to each other with the driven elements fed 180 degrees out of phase
B	Stack two Yagis fed 90 degrees out of phase to form an array with the respective elements in parallel planes
C	Stack two Yagis fed in phase to form an array with the respective elements in parallel planes
D	Arrange two Yagis perpendicular to each other with the driven elements at the same point on the boom fed 90 degrees out of phase

47. - E9E10

Which of these choices is an effective way to match an antenna with a 100-ohm feed point impedance to a 50-ohm coaxial cable feed line?

Select	Answer
A	Insert a 1/4-wavelength piece of 75-ohm coaxial cable transmission line in series between the antenna terminals and the 50-ohm feed cable
B	Connect a 1/2 wavelength shorted stub of 75-ohm cable in parallel with the 50-ohm cable where it attaches to the antenna
C	Connect a 1/4-wavelength open stub of 300-ohm twinlead in parallel with the coaxial feed line where it connects to the antenna
D	Insert a 1/2 wavelength piece of 300-ohm twinlead in series between the antenna terminals and the 50-ohm feed cable

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

49. - E9G08

What is the process of normalization with regard to a Smith chart?

Select	Answer
A	Reassigning impedance values with regard to the prime center
B	Reassigning prime center with regard to the reactance axis
C	Reassigning reactance values with regard to the resistance axis
D	Reassigning resistance values with regard to the reactance axis

50. - E9H01

When constructing a Beverage antenna, which of the following factors should be included in the design to achieve good performance at the desired frequency?

Select	Answer
A	It must be mounted more than 1 wavelength above ground
B	Its overall length must not exceed 1/4 wavelength
C	It should be one or more wavelengths long
D	It should be configured as a four-sided loop

Figure E7-2