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

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	18.107 MHz
B	18.100 MHz
C	18.068 MHz
D	18.110 MHz

3. - E1B06

Which of the following additional rules apply if you are installing an amateur station antenna at a site at or near a public use airport?

Select	Answer
A	You must obtain a construction permit from the airport zoning authority
B	You must file an Environmental Impact Statement with the EPA before construction begins
C	You must submit engineering drawings to the FAA
D	You may have to notify the Federal Aviation Administration and register it with the FCC as required by Part 17 of the FCC rules

4. - E1C06

Which of the following is required in order to operate in accordance with CEPT rules in foreign countries where permitted?

Select	Answer
A	You must bring a copy of FCC Public Notice DA 16-1048
B	You must append "/CEPT" to your call sign
C	You must identify in the official language of the country in which you are operating
D	The U.S. embassy must approve of your operation

5. - E1D10

Which amateur stations are eligible to be telecommand stations of space stations (subject to the privileges of the class of operator license held by the control operator of the station)?

Select	Answer
A	Any amateur station designated by NASA
B	Any amateur station so designated by the space station licensee
C	Any amateur station so designated by the ITU
D	All these choices are correct

6. - E1E11

What must the VE team do if an examinee scores a passing grade on all examination elements needed for an upgrade or new license?

Select	Answer
A	Issue the examinee the new or upgrade license
B	All these choices are correct
C	Photocopy all examination documents and forward them to the FCC for processing
D	Three VEs must certify that the examinee is qualified for the license grant and that they have complied with the administering VE requirements

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

8. - E2A12

What is the purpose of digital store-and-forward functions on an amateur radio satellite?

Select	Answer
A	To relay messages between satellites
B	To upload operational software for the transponder
C	To store digital messages in the satellite for later download by other stations
D	To delay download of telemetry between satellites

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. - E2C12

What technique do individual nodes use to form a mesh network?

Select	Answer
A	Discovery and link establishment protocols
B	Forward error correction and Viterbi codes
C	Custom code plugs for the local trunking systems
D	Acting as store-and-forward digipeaters

11. - E2D03

Which of the following digital modes is especially useful for EME communications?

Select	Answer
A	PACTOR III
B	JT65
C	MSK144
D	Olivia

12. - E2E11

What is the difference between direct FSK and audio FSK?

Select	Answer
A	Direct FSK can transmit faster baud rates
B	Direct FSK applies the data signal to the transmitter VFO, while AFSK transmits tones via phone
C	Only direct FSK can be decoded by computer
D	Direct FSK occupies less bandwidth

13. - E3A03

When scheduling EME contacts, which of these conditions will generally result in the least path loss?

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

14. - E3B12

What is the primary characteristic of chordal hop propagation?

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

15. - E3C07

Which of the following descriptors indicates the greatest solar flare intensity?

Select	Answer
A	Class X
B	Class M
C	Class A
D	Class B

16. - E4A07

Which of the following is an advantage of using an antenna analyzer compared to an SWR bridge to measure antenna SWR?

Select	Answer
A	Antenna analyzers do not need an external RF source
B	Antenna analyzers display a time-varying representation of the modulation envelope
C	Antenna analyzers automatically tune your antenna for resonance
D	All these choices are correct

17. - E4B03

Which S parameter is equivalent to forward gain?

Select	Answer
A	S22
B	S21
C	S11
D	S12

18. - E4C10

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

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

19. - E4D08

What causes intermodulation in an electronic circuit?

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

20. - E4E02

Which of the following types of noise can often be reduced with a digital signal processing noise filter?

Select	Answer
A	All these choices are correct
B	Ignition noise
C	Power line noise
D	Broadband white noise

21. - E5A16

What is the resonant frequency of an RLC circuit if R is 33 ohms, L is 50 microhenries and C is 10 picofarads?

Select	Answer
A	23.5 MHz
B	23.5 kHz
C	7.12 kHz
D	7.12 MHz

22. - E5B09

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

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

23. - E5C12

Which point on Figure E5-1 best represents the impedance of a series circuit consisting of a 300-ohm resistor and a 19-picofarad capacitor at 21.200 MHz?

Select	Answer
A	Point 8
B	Point 3
C	Point 1
D	Point 7

24. - E5D01

What is the result of skin effect?

Select	Answer
A	As frequency increases, RF current flows in a thinner layer of the conductor, closer to the surface
B	Thermal effects on the surface of the conductor decrease the impedance
C	Thermal effects on the surface of the conductor increase the impedance
D	As frequency decreases, RF current flows in a thinner layer of the conductor, closer to the surface

25. - E6A06

What is the beta of a bipolar junction transistor?

Select	Answer
A	The breakdown voltage of the base to collector junction
B	The change in collector current with respect to base current
C	The switching speed
D	The frequency at which the current gain is reduced to 0.707

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

27. - E6C05

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

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

28. - E6D08

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

Select	Answer
A	Powdered-iron cores generally require fewer turns to produce a given inductance
B	Powdered-iron cores use smaller diameter wire for the same inductance
C	Powdered-iron cores generally have greater initial permeability
D	Powdered-iron cores generally maintain their characteristics at higher currents

29. - E6E03

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

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

30. - E6F07

What is a solid-state relay?

Select	Answer
A	A device that uses semiconductors to implement the functions of an electromechanical relay
B	A relay using transistors to drive the relay coil
C	A mechanical relay that latches in the on or off state each time it is pulsed
D	A semiconductor passive delay line

31. - E7A10

What is a truth table?

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

32. - E7B15

What is one way to prevent thermal runaway in a bipolar transistor amplifier?

Select	Answer
A	Neutralization
B	All these choices are correct
C	Use a resistor in series with the emitter
D	Select transistors with high beta

33. - E7C06

What are the distinguishing features of an elliptical filter?

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

34. - E7D05

Which of the following types of linear voltage regulator places a constant load on the unregulated voltage source?

Select	Answer
A	A shunt current source
B	A constant current source
C	A shunt regulator
D	A series regulator

35. - E7E03

What is a frequency discriminator stage in a FM receiver?

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

36. - E7F11

What sets the minimum detectable signal level for a direct-sampling SDR receiver in the absence of atmospheric or thermal noise?

Select	Answer
A	Missing codes and jitter
B	Reference voltage level and sample width in bits
C	Data storage transfer rate
D	Sample clock phase noise

37. - E7G04

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

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

38. - E7H05

How is positive feedback supplied in a Pierce oscillator?

Select	Answer
A	Through link coupling
B	Through a tapped coil
C	Through a quartz crystal
D	Through a neutralizing capacitor

39. - E8A10

What is the purpose of a low-pass filter used in conjunction with a digital-to-analog converter?

Select	Answer
A	Remove harmonics from the output caused by the discrete analog levels generated
B	All these choices are correct
C	Improve accuracy by removing out-of-sequence codes from the input
D	Lower the input bandwidth to increase the effective resolution

40. - E8B05

What is the deviation ratio of an FM-phone signal having a maximum frequency swing of plus-or-minus 5 kHz when the maximum modulation frequency is 3 kHz?

Select	Answer
A	60
B	0.167
C	0.6
D	1.67

41. - E8C11

What is the relationship between symbol rate and baud?

Select	Answer
A	Baud is twice the symbol rate
B	They are the same
C	Symbol rate is only used for packet-based modes
D	Baud is only used for RTTY

42. - E8D09

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

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

43. - E9A07

What is the effective isotropic radiated power of a repeater station with 200 watts transmitter power output, 2 dB feed line loss, 2.8 dB duplexer loss, 1.2 dB circulator loss, and 7 dBi antenna gain?

Select	Answer
A	632 watts
B	63.2 watts
C	252 watts
D	159 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	The resulting design will favor radiation of harmonic energy
B	The computed feed point impedance may be incorrect
C	The antenna will become mechanically unstable
D	Ground conductivity will not be accurately modeled

45. - E9C02

What is the radiation pattern of two 1/4-wavelength vertical antennas spaced 1/4 wavelength apart and fed 90 degrees out of phase?

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

46. - E9D06

What happens to the SWR bandwidth when one or more loading coils are used to resonate an electrically short antenna?

Select	Answer
A	It is decreased
B	It is unchanged if the loading coil is located at a voltage maximum point
C	It is increased
D	It is unchanged if the loading coil is located at the feed point

47. - E9E08

What is a use for a Wilkinson divider?

Select	Answer
A	It is used to divide power equally between two 50-ohm loads while maintaining 50-ohm input impedance
B	It is used to feed high-impedance antennas from a low-impedance source
C	It divides the operating frequency of a transmitter signal so it can be used on a lower frequency band
D	It is used to feed low-impedance loads from a high-impedance source

48. - E9F04

What impedance does a 1/2-wavelength transmission line present to a generator when the line is shorted at the far end?

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

49. - E9G03

Which of the following is often determined using a Smith chart?

Select	Answer
A	Beam headings and radiation patterns
B	Satellite azimuth and elevation bearings
C	Trigonometric functions
D	Impedance and SWR values in transmission lines

50. - E9H05

What is the main drawback of a small wire-loop antenna for direction finding?

Select	Answer
A	It is practical for use only on VHF and higher bands
B	It has a bidirectional pattern
C	It has no clearly defined null
D	All these choices are correct

Figure E5-1