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

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1. - E0A02

When evaluating RF exposure levels from your station at a neighbor's home, what must you do?

Select	Answer
A	Ensure signals from your station are less than the controlled Maximum Permitted Exposure (MPE) limits
B	Ensure signals from your station are less than the uncontrolled Maximum Permitted Exposure (MPE) limits
C	Ensure signals from your station are less than the uncontrolled Maximum Permitted Emission (MPE) limits
D	Ensure signals from your station are less than the controlled Maximum Permitted Emission (MPE) limits

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

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	10 kHz
B	15 kHz
C	20 kHz
D	3 kHz

4. - E1C10

What is the permitted mean power of any spurious emission relative to the mean power of the fundamental emission from a station transmitter or external RF amplifier installed after January 1, 2003 and transmitting on a frequency below 30 MHz?

Select	Answer
A	At least 43 dB below
B	At least 73 dB below
C	At least 63 dB below
D	At least 53 dB below

5. - E1D06

What is the maximum permitted transmitter output power when operating a model craft by telecommand?

Select	Answer
A	2 watts
B	5 watts
C	1 watt
D	100 watts

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

7. - E1F11

Which of the following best describes one of the standards that must be met by an external RF power amplifier if it is to qualify for a grant of FCC certification?

Select	Answer
A	It must produce full legal output when driven by not more than 5 watts of mean RF input power
B	It must exhibit a gain of 0 dB or less over its full output range
C	It must be capable of external RF switching between its input and output networks
D	It must satisfy the FCC's spurious emission standards when operated at the lesser of 1500 watts or its full output power

8. - E2A05

What do the letters in a satellite's mode designator specify?

Select	Answer
A	The location of the ground control station
B	The polarization of uplink and downlink signals
C	The uplink and downlink frequency ranges
D	Power limits for uplink and downlink transmissions

9. - E2B05

Which of the following describes the use of vestigial sideband in analog fast-scan TV transmissions?

Select	Answer
A	The vestigial sideband contains chroma information
B	The vestigial sideband carries the audio information
C	Vestigial sideband provides high frequency emphasis to sharpen the picture
D	Vestigial sideband reduces bandwidth while allowing for simple video detector circuitry

10. - E2C11

How should you generally identify your station when attempting to contact a DX station during a contest or in a pileup?

Select	Answer
A	Send your full call sign and grid square
B	Send the call sign of the DX station three times, the words this is,then your call sign three times
C	Send only the last two letters of your call sign until you make contact
D	Send your full call sign once or twice

11. - E2D03

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

Select	Answer
A	Olivia
B	MSK144
C	PACTOR III
D	JT65

12. - E2E11

What is the difference between direct FSK and audio FSK?

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

13. - E3A09

Which of the following frequency ranges is most suited for meteor scatter communications?

Select	Answer
A	28 MHz - 148 MHz
B	220 MHz - 450 MHz
C	10 MHz - 14 MHz
D	1.8 MHz - 1.9 MHz

14. - E3B02

What is the approximate maximum range for signals using transequatorial propagation?

Select	Answer
A	2500 miles
B	5000 miles
C	7500 miles
D	1000 miles

15. - E3C04

What does the value of Bz (B sub Z) represent?

Select	Answer
A	Geomagnetic field stability
B	Direction and strength of the interplanetary magnetic field
C	Critical frequency for vertical transmissions
D	Duration of long-delayed echoes

16. - E4A04

How is the compensation of an oscilloscope probe typically adjusted?

Select	Answer
A	A frequency standard is displayed and the probe is adjusted until the deflection time is accurate
B	A high frequency sine wave is displayed and the probe is adjusted for maximum amplitude
C	A square wave is displayed and the probe is adjusted until the horizontal portions of the displayed wave are as nearly flat as possible
D	A DC voltage standard is displayed and the probe is adjusted until the displayed voltage is accurate

17. - E4B02

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

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

18. - E4C07

What does the MDS of a receiver represent?

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

19. - E4D02

Which of the following describes problems caused by poor dynamic range in a receiver?

Select	Answer
A	Oscillator instability and severe audio distortion of all but the strongest received signals
B	Spurious signals caused by cross-modulation and desensitization from strong adjacent signals
C	Cross-modulation of the desired signal and insufficient audio power to operate the speaker
D	Oscillator instability requiring frequent retuning and loss of ability to recover the opposite sideband

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

21. - E5A01

What can cause the voltage across reactances in a series RLC circuit to be higher than the voltage applied to the entire circuit?

Select	Answer
A	Conductance
B	Resonance
C	Capacitance
D	Resistance

22. - E5B05

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

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

23. - E5C10

Which point on Figure E5-1 best represents the impedance of a series circuit consisting of a 400-ohm resistor and a 38-picofarad capacitor at 14 MHz?

Select	Answer
A	Point 5
B	Point 4
C	Point 6
D	Point 2

24. - E5D08

How many watts are consumed in a circuit having a power factor of 0.6 if the input is 200VAC at 5 amperes?

Select	Answer
A	200 watts
B	1600 watts
C	1000 watts
D	600 watts

25. - E6A02

Which of the following semiconductor materials contains excess free electrons?

Select	Answer
A	N-type
B	Bipolar
C	Insulated gate
D	P-type

26. - E6B04

What type of semiconductor device is designed for use as a voltage-controlled capacitor?

Select	Answer
A	Zener diode
B	Tunnel diode
C	Silicon-controlled rectifier
D	Varactor diode

27. - E6C04

Which of the following is an advantage of BiCMOS logic?

Select	Answer
A	It has the high input impedance of CMOS and the low output impedance of bipolar transistors
B	It is immune to electrostatic damage
C	All these choices are correct
D	Its simplicity results in much less expensive devices than standard CMOS

28. - E6D01

Why should core saturation of an impedance matching transformer be avoided?

Select	Answer
A	Magnetic flux would increase with frequency
B	RF susceptance would increase
C	Harmonics and distortion could result
D	Temporary changes of the core permeability could result

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. - E6F03

What is the most common configuration of an optoisolator or optocoupler?

Select	Answer
A	A lens and a photomultiplier
B	A frequency modulated helium-neon laser
C	An amplitude modulated helium-neon laser
D	An LED and a phototransistor

31. - E7A02

What is the function of a decade counter?

Select	Answer
A	It decodes a binary number for display on a seven-segment LED display
B	It decodes a decimal number for display on a seven-segment LED display
C	It produces 10 output pulses for every input pulse
D	It produces one output pulse for every 10 input pulses

32. - E7B17

Why are odd-order rather than even-order intermodulation distortion products of concern in linear power amplifiers?

Select	Answer
A	Because they are relatively far in frequency from the desired signal
B	Because they are relatively close in frequency to the desired signal
C	Because they invert the sidebands causing distortion
D	Because they maintain the sidebands, thus causing multiple duplicate signals

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. - E7D11

What is the function of the pass transistor in a linear voltage regulator circuit?

Select	Answer
A	Maintains nearly constant output voltage over a wide range of load current
B	Maintains nearly constant output impedance over a wide range of load current
C	Permits a wide range of output voltage settings
D	Provides a stable input impedance over a wide range of source voltage

35. - E7E07

What is meant by the term "baseband" in radio communications?

Select	Answer
A	The unmodulated bandwidth of the transmitted signal
B	The lowest frequency band that the transmitter or receiver covers
C	The basic oscillator frequency in an FM transmitter that is multiplied to increase the deviation and carrier frequency
D	The frequency range occupied by a message signal prior to modulation

36. - E7F03

What type of digital signal processing filter is used to generate an SSB signal?

Select	Answer
A	An elliptical filter
B	A Hilbert-transform filter
C	A notch filter
D	An adaptive filter

37. - E7G11

What absolute voltage gain can be expected from the circuit in Figure E7-3 when R1 is 3300 ohms and RF is 47 kilohms?

Select	Answer
A	14
B	0.07
C	7
D	28

38. - E7H10

What information is contained in the lookup table of a direct digital synthesizer (DDS)?

Select	Answer
A	Amplitude values that represent the desired waveform
B	The phase relationship between a voltage-controlled oscillator and the output waveform
C	Frequently used receiver and transmitter frequencies
D	The phase relationship between a reference oscillator and the output waveform

39. - E8A11

Which of the following is a measure of the quality of an analog-to-digital converter?

Select	Answer
A	Reciprocal mixing
B	Total harmonic distortion
C	Power factor
D	Peak envelope power

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	2000
B	3
C	1/3
D	6000

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 number of characters carried per second by the station-to-station link
C	The number of control characters in a message packet
D	The duration of each bit in a message sent over the air

42. - E8D07

What is a common cause of overmodulation of AFSK signals?

Select	Answer
A	Excessive transmit audio levels
B	Excessive numbers of retries
C	Ground loops
D	Bit errors in the modem

43. - E9A06

What is the effective radiated power relative to a dipole of a repeater station with 200 watts transmitter power output, 4 dB feed line loss, 3.2 dB duplexer loss, 0.8 dB circulator loss, and 10 dBd antenna gain?

Select	Answer
A	2000 watts
B	300 watts
C	317 watts
D	126 watts

44. - E9B02

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

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

45. - E9C10

Which of the following describes a Zepp antenna?

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

46. - E9D04

Why should an HF mobile antenna loading coil have a high ratio of reactance to resistance?

Select	Answer
A	To swamp out harmonics
B	To minimize losses
C	To lower the radiation angle
D	To minimize the Q

47. - E9E04

What is the purpose of the series capacitor in a gamma-type antenna matching network?

Select	Answer
A	To transform the antenna impedance to a higher value
B	To provide DC isolation between the feed line and the antenna
C	To cancel the inductive reactance of the matching network
D	To provide a rejection notch that prevents the radiation of harmonics

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

49. - E9G02

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

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

50. - E9H10

How can the output voltage of a multiple-turn receiving loop antenna be increased?

Select	Answer
A	By winding adjacent turns in opposing directions
B	By reducing the permeability of the loop shield
C	By utilizing high impedance wire for the coupling loop
D	By increasing the number of turns and/or the area

Figure E5-1

Figure E7-3

Figure E9-1