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

Logging in (or registering) will help the system to select questions that you need to focus on.

1. - E0A05

What is one of the potential hazards of operating in the amateur radio microwave bands?

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

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

3. - E1B03

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

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

4. - E1C04

What is meant by IARP?

Select	Answer
A	An indication of increased antenna reflected power
B	A forecast of intermittent aurora radio propagation
C	An international amateur radio permit that allows U.S. amateurs to operate in certain countries of the Americas
D	The internal amateur radio practices policy of the FCC

5. - E1D01

What is the definition of telemetry?

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

6. - E1E08

To which of the following examinees may a VE not administer an examination?

Select	Answer
A	Friends of the VE
B	Employees of the VE
C	Relatives of the VE as listed in the FCC rules
D	All these choices are correct

7. - E1F01

On what frequencies are spread spectrum transmissions permitted?

Select	Answer
A	Only on amateur frequencies above 420 MHz
B	Only on amateur frequencies above 144 MHz
C	Only on amateur frequencies above 222 MHz
D	Only on amateur frequencies above 50 MHz

8. - E2A03

How is the signal inverted by an inverting linear transponder?

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

9. - E2B12

What signals SSTV receiving software to begin a new picture line?

Select	Answer
A	Specific tone amplitudes
B	A two-tone signal
C	Specific tone frequencies
D	Elapsed time

10. - E2C12

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

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

11. - E2D07

What digital protocol is used by APRS?

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

12. - E2E11

What is the difference between direct FSK and audio FSK?

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

13. - E3A06

What might help to restore contact when DX signals become too weak to copy across an entire HF band a few hours after sunset?

Select	Answer
A	Switch to a lower frequency HF band
B	Wait 90 minutes or so for the signal degradation to pass
C	Wait 24 hours before attempting another communication on the band
D	Switch to a higher frequency HF band

14. - E3B12

What is the primary characteristic of chordal hop propagation?

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

15. - E3C15

What might be indicated by a sudden rise in radio background noise across a large portion of the HF spectrum?

Select	Answer
A	A solar flare has occurred
B	Increased transequatorial propagation is likely
C	Long-path propagation is likely
D	A temperature inversion has occurred

16. - E4A05

What is the purpose of the prescaler function on a frequency counter?

Select	Answer
A	It multiplies a higher frequency signal so a low-frequency counter can display the operating frequency
B	It amplifies low-level signals for more accurate counting
C	It prevents oscillation in a low-frequency counter circuit
D	It divides a higher frequency signal so a low-frequency counter can display the input frequency

17. - E4B03

Which S parameter is equivalent to forward gain?

Select	Answer
A	S22
B	S11
C	S12
D	S21

18. - E4C05

What does a receiver noise floor of -174 dBm represent?

Select	Answer
A	The theoretical noise in a 1 Hz bandwidth at the input of a perfect receiver at room temperature
B	The minimum detectable signal as a function of receive frequency
C	The galactic noise contribution to minimum detectable signal
D	The noise figure of a 1 Hz bandwidth receiver

19. - E4D02

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

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

20. - E4E06

What is one type of electrical interference that might be caused by a nearby personal computer?

Select	Answer
A	The appearance of unstable modulated or unmodulated signals at specific frequencies
B	A clicking noise at intervals of a few seconds
C	A loud AC hum in the audio output of your station receiver
D	A whining type noise that continually pulses off and on

21. - E5A09

How is the Q of an RLC parallel resonant circuit calculated?

Select	Answer
A	Reactance of either the inductance or capacitance multiplied by the resistance
B	Resistance divided by the reactance of either the inductance or capacitance
C	Reactance of either the inductance or capacitance divided by the resistance
D	Reactance of the inductance multiplied by the reactance of the capacitance

22. - E5B12

What is admittance?

Select	Answer
A	The inverse of Q factor
B	The term for the gain of a field effect transistor
C	The turns ratio of a transformer
D	The inverse of impedance

23. - E5C04

What coordinate system is often used to display the resistive, inductive, and/or capacitive reactance components of impedance?

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

24. - E5D07

How many watts are consumed in a circuit having a power factor of 0.71 if the apparent power is 500VA?

Select	Answer
A	252 W
B	704 W
C	355 W
D	1.42 mW

25. - E6A06

What is the beta of a bipolar junction transistor?

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

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

28. - E6D10

What is a primary advantage of using a toroidal core instead of a solenoidal core in an inductor?

Select	Answer
A	Toroidal cores have lower Q characteristics
B	Toroidal cores confine most of the magnetic field within the core material
C	Toroidal cores exhibit greater hysteresis
D	Toroidal cores make it easier to couple the magnetic energy into other components

29. - E6E04

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

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

30. - E6F06

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

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

31. - E7A04

How many flip-flops are required to divide a signal frequency by 4?

Select	Answer
A	1
B	8
C	2
D	4

32. - E7B07

Which of the following is a likely result when a Class C amplifier is used to amplify a single-sideband phone signal?

Select	Answer
A	Increased overall intelligibility
B	Signal distortion and excessive bandwidth
C	Signal inversion
D	Reduced intermodulation products

33. - E7C11

Which of the following describes a receiving filter's ability to reject signals occupying an adjacent channel?

Select	Answer
A	Shape factor
B	Passband ripple
C	Noise factor
D	Phase response

34. - E7D01

How does a linear electronic voltage regulator work?

Select	Answer
A	The conduction of a control element is varied to maintain a constant output voltage
B	It eliminates the need for a pass transistor
C	It has a ramp voltage as its output
D	The control element duty cycle is proportional to the line or load conditions

35. - E7E10

How does a diode envelope detector function?

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

36. - E7F10

What aspect of receiver analog-to-digital conversion determines the maximum receive bandwidth of a Direct Digital Conversion SDR?

Select	Answer
A	Sample rate
B	Sample clock phase noise
C	Sample width in bits
D	Processor latency

37. - E7G07

What magnitude of voltage gain can be expected from the circuit in Figure E73 when R1 is 10 ohms and RF is 470 ohms?

Select	Answer
A	47
B	24
C	94
D	0.21

38. - E7H03

How is positive feedback supplied in a Hartley oscillator?

Select	Answer
A	Through a neutralizing capacitor
B	Through link coupling
C	Through a tapped coil
D	Through a capacitive divider

39. - E8A05

What of the following instruments would be the most accurate for measuring the RMS voltage of a complex waveform?

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

40. - E8B09

What is deviation ratio?

Select	Answer
A	The ratio of the audio modulating frequency to the center carrier frequency
B	The ratio of the highest audio modulating frequency to the average audio modulating frequency
C	The ratio of the maximum carrier frequency deviation to the highest audio modulating frequency
D	The ratio of the carrier center frequency to the audio modulating frequency

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. - E8D09

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

Select	Answer
A	-30 dB
B	+10 dB
C	-20 dB
D	+15 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	159 watts
B	252 watts
C	632 watts
D	63.2 watts

44. - E9B09

What type of computer program technique is commonly used for modeling antennas?

Select	Answer
A	Graphical analysis
B	Mutual impedance analysis
C	Method of Moments
D	Calculus differentiation with respect to physical properties

45. - E9C12

Which of the following describes an Extended Double Zepp antenna?

Select	Answer
A	A center-fed 1.25-wavelength antenna (two 5/8-wave elements in phase)
B	An end-fed folded dipole antenna
C	A portable antenna erected using two push support poles
D	A wideband vertical antenna constructed from precisely tapered aluminum tubing

46. - E9D12

Which of the following would provide the best RF ground for your station?

Select	Answer
A	An electrically short connection to a metal water pipe
B	A 50-ohm resistor connected to ground
C	An electrically short connection to 3 or 4 interconnected ground rods driven into the Earth
D	An electrically short connection to 3 or 4 interconnected ground rods via a series RF choke

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	50 ohms
B	75 ohms
C	62 ohms
D	450 ohms

48. - E9F06

What is the approximate physical length of an air-insulated, parallel conductor transmission line that is electrically 1/2 wavelength long at 14.10 MHz?

Select	Answer
A	7.0 meters
B	10.6 meters
C	13.3 meters
D	8.5 meters

49. - E9G05

Which of the following is a common use for a Smith chart?

Select	Answer
A	Determine the impedance of a transmission line, given the physical dimensions
B	Determine the gain of an antenna given the physical and electrical parameters
C	Determine the loss/100 feet of a transmission line, given the velocity factor and conductor materials
D	Determine the length and position of an impedance matching stub

50. - E9H09

What is a Pennant antenna?

Select	Answer
A	A small, vertically oriented receiving antenna consisting of a triangular loop terminated in approximately 900 ohms
B	A four-element, high-gain vertical array invented by George Pennant
C	A form of rhombic antenna terminated in a variable capacitor to provide frequency diversity
D	A stealth antenna built to look like a flagpole