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

2. - E1A02

When using a transceiver that displays the carrier frequency of phone signals, which of the following displayed frequencies represents the lowest frequency at which a properly adjusted LSB emission will be totally within the band?

Select	Answer
A	1 kHz above the lower band edge
B	300 Hz above the lower band edge
C	The exact lower band edge
D	3 kHz above the lower band edge

3. - E1B03

Within what distance must an amateur station protect an FCC monitoring facility from harmful interference?

Select	Answer
A	10 miles
B	3 miles
C	1 mile
D	30 miles

4. - E1C02

Which of the following types of communications may be transmitted to amateur stations in foreign countries?

Select	Answer
A	Business-related messages for non-profit organizations
B	All these choices are correct
C	Messages intended for users of the maritime satellite service
D	Communications incidental to the purpose of the amateur service and remarks of a personal nature

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

6. - E1E12

What must the VE team do with the application form if the examinee does not pass the exam?

Select	Answer
A	Maintain the application form with the VEC's records
B	Send the application form to the FCC and inform the FCC of the grade
C	Destroy the application form
D	Return the application document to the examinee

7. - E1F07

When may an amateur station send a message to a business?

Select	Answer
A	When neither the amateur nor his or her employer has a pecuniary interest in the communications
B	When the total money involved does not exceed $25
C	When transmitting international third-party communications
D	When the control operator is employed by the FCC or another government agency

8. - E2A03

How is the signal inverted by an inverting linear transponder?

Select	Answer
A	The signal is passed through a non-linear filter
B	The signal is reduced to I and Q components and the Q component is filtered out
C	The signal is passed through a mixer and the difference rather than the sum is transmitted
D	The signal is detected and remodulated on the reverse sideband

9. - E2B06

What is vestigial sideband modulation?

Select	Answer
A	Spread spectrum modulation achieved by applying FM modulation following single sideband amplitude modulation
B	Amplitude modulation in which one complete sideband and a portion of the other are transmitted
C	A type of modulation in which one sideband is inverted
D	Narrow-band FM modulation achieved by filtering one sideband from the audio before frequency modulating the carrier

10. - E2C07

What is the Cabrillo format?

Select	Answer
A	The most common set of contest rules
B	A standard for submission of electronic contest logs
C	A method of exchanging information during a contest QSO
D	The rules of order for meetings between contest sponsors

11. - E2D02

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

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

12. - E2E10

Which of these digital modes has the narrowest bandwidth?

Select	Answer
A	MFSK16
B	300-baud packet
C	170 Hz shift, 45-baud RTTY
D	PSK31

13. - E3A11

What is a typical range for tropospheric propagation of microwave signals?

Select	Answer
A	100 miles to 300 miles
B	2500 miles
C	10 miles to 50 miles
D	1200 miles

14. - E3B06

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

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

15. - E3C09

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

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

16. - E4A02

Which of the following parameters does a spectrum analyzer display on the vertical and horizontal axes?

Select	Answer
A	RF amplitude and frequency
B	RF amplitude and time
C	SWR and frequency
D	SWR and time

17. - E4B10

Which of the following methods measures intermodulation distortion in an SSB transmitter?

Select	Answer
A	Modulate the transmitter using two RF signals having harmonically related frequencies and observe the RF output with a logic analyzer
B	Modulate the transmitter using two RF signals having non-harmonically related frequencies and observe the RF output with a spectrum analyzer
C	Modulate the transmitter using two AF signals having non-harmonically related frequencies and observe the RF output with a spectrum analyzer
D	Modulate the transmitter using two AF signals having harmonically related frequencies and observe the RF output with a peak reading wattmeter

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. - 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	Oscillator instability requiring frequent retuning and loss of ability to recover the opposite sideband
C	Cross-modulation of the desired signal and insufficient audio power to operate the speaker
D	Spurious signals caused by cross-modulation and desensitization from strong adjacent signals

20. - E4E08

What current flows equally on all conductors of an unshielded multi-conductor cable?

Select	Answer
A	Common-mode current
B	Reactive current only
C	Return current
D	Differential-mode current

21. - E5A07

What is the magnitude of the current at the input of a parallel RLC circuit at resonance?

Select	Answer
A	R/L
B	Maximum
C	Minimum
D	L/R

22. - E5B09

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

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

23. - E5C08

What coordinate system is often used to display the phase angle of a circuit containing resistance, inductive and/or capacitive reactance?

Select	Answer
A	Elliptical coordinates
B	Faraday grid
C	Polar coordinates
D	Maidenhead grid

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

25. - E6A06

What is the beta of a bipolar junction transistor?

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

26. - E6B03

What type of bias is required for an LED to emit light?

Select	Answer
A	Inductive bias
B	Zero bias
C	Reverse bias
D	Forward bias

27. - E6C06

Why do CMOS digital integrated circuits have high immunity to noise on the input signal or power supply?

Select	Answer
A	Large bypass capacitance is inherent
B	The input switching threshold is about one-half the power supply voltage
C	Bandwidth is very limited
D	The input switching threshold is about two times the power supply voltage

28. - E6D09

What devices are commonly used as VHF and UHF parasitic suppressors at the input and output terminals of a transistor HF amplifier?

Select	Answer
A	Ferrite beads
B	Electrolytic capacitors
C	Steel-core toroids
D	Butterworth filters

29. - E6E04

Which is the most common input and output impedance of circuits that use MMICs?

Select	Answer
A	450 ohms
B	50 ohms
C	300 ohms
D	10 ohms

30. - E6F04

What is the photovoltaic effect?

Select	Answer
A	The conversion of electrical energy to mechanical energy
B	The conversion of light to electrical energy
C	The tendency of a battery to discharge when exposed to light
D	The conversion of voltage to current when exposed to light

31. - E7A11

What type of logic defines "1" as a high voltage?

Select	Answer
A	Assertive Logic
B	Positive Logic
C	Negative logic
D	Reverse Logic

32. - E7B06

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

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

33. - E7C04

How does an impedance-matching circuit transform a complex impedance to a resistive impedance?

Select	Answer
A	It introduces negative resistance to cancel the resistive part of impedance
B	Reactive currents are dissipated in matched resistances
C	It cancels the reactive part of the impedance and changes the resistive part to a desired value
D	It introduces transconductance to cancel the reactive part of impedance

34. - E7D13

What is the equation for calculating power dissipated by a series linear voltage regulator?

Select	Answer
A	Voltage difference from input to output multiplied by output current
B	Output voltage multiplied by output current
C	Input voltage multiplied by input current
D	Input voltage divided by output current

35. - E7E10

How does a diode envelope detector function?

Select	Answer
A	By mixing signals with noise in the transition region of the diode
B	By breakdown of the Zener voltage
C	By rectification and filtering of RF signals
D	By sensing the change of reactance in the diode with respect to frequency

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

37. - E7G01

What is the typical output impedance of an op-amp?

Select	Answer
A	100 ohms
B	Very low
C	1000 ohms
D	Very high

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. - 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. - E8B01

What is the modulation index of an FM signal?

Select	Answer
A	The bandwidth of the transmitted signal divided by the modulating signal frequency
B	The ratio of modulating signal amplitude to frequency deviation
C	The ratio of frequency deviation to modulating signal frequency
D	The type of modulation used by the transmitter

41. - E8C01

How is Forward Error Correction implemented?

Select	Answer
A	By varying the frequency shift of the transmitted signal according to a predefined algorithm
B	By transmitting extra data that may be used to detect and correct transmission errors
C	By transmitting a special algorithm to the receiving station along with the data characters
D	By the receiving station repeating each block of three data characters

42. - E8D09

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

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

43. - E9A10

Which of the following improves the efficiency of a ground-mounted quarter-wave vertical antenna?

Select	Answer
A	Isolating the coax shield from ground
B	Shortening the radiating element
C	Installing a radial system
D	All these choices are correct

44. - E9B10

What is the principle of a Method of Moments analysis?

Select	Answer
A	A wire is modeled as a series of segments, each having a distinct value of voltage across it
B	A wire is modeled as a series of segments, each having a uniform value of current
C	A wire is modeled as a single sine-wave current generator
D	A wire is modeled as a single sine-wave voltage source

45. - E9C09

Which of the following describes a G5RV antenna?

Select	Answer
A	A wide band dipole using shorted coaxial cable for the radiating elements and fed with a�4:1 balun
B	A multi-band dipole antenna fed with coax and a balun through a selected length of open wire transmission line
C	A phased array antenna consisting of multiple loops
D	A multi-band trap antenna

46. - E9D05

What usually occurs if a Yagi antenna is designed solely for maximum forward gain?

Select	Answer
A	The front-to-back ratio increases
B	The front-to-back ratio decreases
C	The SWR is reduced
D	The frequency response is widened over the whole frequency band

47. - E9E03

What is the name of the matching system that uses a section of transmission line connected in parallel with the feed line at or near the feed point?

Select	Answer
A	The omega match
B	The delta match
C	The gamma match
D	The stub match

48. - E9F09

What is the approximate physical length of a foam polyethylene dielectric coaxial transmission line that is electrically 1/4 wavelength long at 7.2 MHz?

Select	Answer
A	10.4 meters
B	6.9 meters
C	5.2 meters
D	8.3 meters

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	Polar axis
D	Prime axis

50. - E9H07

Why is RF attenuation used when direction-finding?

Select	Answer
A	To narrow the receiver bandwidth
B	To increase receiver sensitivity
C	To prevent receiver overload which reduces pattern nulls
D	To compensate for isotropic directivity and the antenna effect of feed lines

Figure E9-3