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

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1. - E0A10

What toxic material may be present in some electronic components such as high voltage capacitors and transformers?

Select	Answer
A	Polymorphic silicon
B	Polychlorinated biphenyls
C	Polyethylene
D	Polytetrafluoroethylene

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

3. - E1B03

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

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

4. - E1C03

How do the control operator responsibilities of a station under automatic control differ from one under local control?

Select	Answer
A	Under local control there is no control operator
B	Under automatic control the control operator is not required to be present at the control point
C	Under automatic control there is no control operator
D	Under local control a control operator is not required to be present at a control point

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	One-way transmission of measurements at a distance from the measuring instrument
C	Two-way transmissions of data
D	Two-way transmissions in excess of 1000 feet

6. - E1E02

Who does Part 97 task with maintaining the pools of questions for all U.S. amateur license examinations?

Select	Answer
A	The ARRL
B	The VEs
C	The FCC
D	The VECs

7. - E1F04

Which of the following geographic descriptions approximately describes "Line A"?

Select	Answer
A	A line roughly parallel to and south of the border between the U.S. and Canada
B	A line roughly parallel to and east of the U.S. Pacific coastline
C	A line roughly parallel to and north of the border between the U.S. and Mexico
D	A line roughly parallel to and west of the U.S. Atlantic coastline

8. - E2A11

What type of antenna can be used to minimize the effects of spin modulation and Faraday rotation?

Select	Answer
A	An isotropic antenna
B	A circularly polarized antenna
C	A linearly polarized antenna
D	A log-periodic dipole array

9. - E2B11

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

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

10. - E2C03

From which of the following bands is amateur radio contesting generally excluded?

Select	Answer
A	33 centimeters
B	6 meters
C	2 meters
D	30 meters

11. - E2D07

What digital protocol is used by APRS?

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

12. - E2E07

Which of the following is a possible reason that attempts to initiate contact with a digital station on a clear frequency are unsuccessful?

Select	Answer
A	Your transmit frequency is incorrect
B	The protocol version you are using is not supported by the digital station
C	Another station you are unable to hear is using the frequency
D	All these choices are correct

13. - E3A09

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

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

14. - E3B12

What is the primary characteristic of chordal hop propagation?

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

15. - E3C02

What is indicated by a rising A or K index?

Select	Answer
A	Higher levels of solar UV radiation
B	Increasing disruption of the geomagnetic field
C	An increase in the critical frequency
D	Decreasing disruption of the geomagnetic field

16. - E4A03

Which of the following test instruments is used to display spurious signals and/or intermodulation distortion products generated by an SSB transmitter?

Select	Answer
A	A wattmeter
B	A time-domain reflectometer
C	A logic analyzer
D	A spectrum analyzer

17. - E4B08

Which of the following can be used to measure the Q of a series-tuned circuit?

Select	Answer
A	The frequency shift
B	The bandwidth of the circuit's frequency response
C	The resonant frequency of the circuit
D	The inductance to capacitance ratio

18. - E4C14

What transmit frequency might generate an image response signal in a receiver tuned to 14.300 MHz and that uses a 455 kHz IF frequency?

Select	Answer
A	14.445 MHz
B	13.845 MHz
C	15.210 MHz
D	14.755 MHz

19. - E4D08

What causes intermodulation in an electronic circuit?

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

20. - E4E05

How can radio frequency interference from an AC motor be suppressed?

Select	Answer
A	By installing a bypass capacitor in series with the motor leads
B	By installing a brute-force AC-line filter in series with the motor leads
C	By using a ground-fault current interrupter in the circuit used to power the motor
D	By installing a high-pass filter in series with the motor's power leads

21. - E5A13

What is an effect of increasing Q in a series resonant circuit?

Select	Answer
A	Parasitic effects are minimized
B	Internal voltages increase
C	Phase shift can become uncontrolled
D	Fewer components are needed for the same performance

22. - E5B07

What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 500 ohms, R is 1 kilohm, and XL is 250 ohms?

Select	Answer
A	14.0 degrees with the voltage lagging the current
B	68.2 degrees with the voltage leading the current
C	68.2 degrees with the voltage lagging the current
D	14.0 degrees with the voltage leading the current

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 1
C	Point 3
D	Point 7

24. - E5D03

What is microstrip?

Select	Answer
A	Precision printed circuit conductors above a ground plane that provide constant impedance interconnects at microwave frequencies
B	Short lengths of coax mounted on printed circuit boards to minimize time delay between microwave circuits
C	Miniature coax used for low power applications
D	Lightweight transmission line made of common zip cord

25. - E6A04

What is the name given to an impurity atom that adds holes to a semiconductor crystal structure?

Select	Answer
A	N-type impurity
B	Insulator impurity
C	Acceptor impurity
D	Donor impurity

26. - E6B11

What is used to control the attenuation of RF signals by a PIN diode?

Select	Answer
A	A sub-harmonic pump signal
B	Forward DC bias current
C	Reverse voltage larger than the RF signal
D	Capacitance of an RF coupling capacitor

27. - E6C02

What happens when the level of a comparator's input signal crosses the threshold?

Select	Answer
A	The IC input can be damaged
B	The comparator enters latch-up
C	The comparator changes its output state
D	The feedback loop becomes unstable

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

29. - E6E04

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

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

30. - E6F01

What absorbs the energy from light falling on a photovoltaic cell?

Select	Answer
A	Electrons
B	Protons
C	Holes
D	Photons

31. - E7A09

What logical operation is performed by an exclusive NOR gate?

Select	Answer
A	It produces logic 1 at its output only if all inputs are logic 1
B	It produces logic 0 at its output only if all inputs are logic 0
C	It produces logic 0 at its output if only one input is logic 1
D	It produces logic 1 at its output if only one input is logic 1

32. - E7B05

What can be done to prevent unwanted oscillations in an RF power amplifier?

Select	Answer
A	Tune the stage for maximum SWR
B	Tune both the input and output for maximum power
C	Install parasitic suppressors and/or neutralize the stage
D	Use a phase inverter in the output filter

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. - E7D13

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

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

35. - E7E01

Which of the following can be used to generate FM phone emissions?

Select	Answer
A	A reactance modulator on the final amplifier
B	A balanced modulator on the audio amplifier
C	A reactance modulator on the oscillator
D	A balanced modulator on the oscillator

36. - E7F13

What is the function of taps in a digital signal processing filter?

Select	Answer
A	Provide incremental signal delays for filter algorithms
B	Provide access for debugging software
C	Select the point at which baseband signals are generated
D	To reduce excess signal pressure levels

37. - E7G09

What will be the output voltage of the circuit shown in Figure E7-3 if R1 is 1000 ohms, RF is 10,000 ohms, and 0.23 volts DC is applied to the input?

Select	Answer
A	-2.3 volts
B	2.3 volts
C	0.23 volts
D	-0.23 volts

38. - E7H12

Which of the following must be done to ensure that a crystal oscillator provides the frequency specified by the crystal manufacturer?

Select	Answer
A	Bias the crystal at a specified voltage
B	Provide the crystal with a specified parallel inductance
C	Provide the crystal with a specified parallel capacitance
D	Bias the crystal at a specified current

39. - E8A02

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

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

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	0.6
B	60
C	0.167
D	1.67

41. - E8C12

What factors affect the bandwidth of a transmitted CW signal?

Select	Answer
A	Keying speed and shape factor (rise and fall time)
B	All these choices are correct
C	Modulation index and output power
D	IF bandwidth and Q

42. - E8D04

What is the primary effect of extremely short rise or fall time on a CW signal?

Select	Answer
A	Limits data speed
B	The generation of key clicks
C	The generation of RF harmonics
D	More difficult to copy

43. - E9A12

How much gain does an antenna have compared to a 1/2-wavelength dipole when it has 6 dB gain over an isotropic antenna?

Select	Answer
A	2.79 dB
B	3.85 dB
C	8.15 dB
D	6.0 dB

44. - E9B03

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

Select	Answer
A	24 dB
B	14 dB
C	12 dB
D	18 dB

45. - E9C10

Which of the following describes a Zepp antenna?

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

46. - E9D07

What is an advantage of using top loading in a shortened HF vertical antenna?

Select	Answer
A	Greater structural strength
B	Lower Q
C	Improved radiation efficiency
D	Higher losses

47. - E9E04

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

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

48. - E9F13

What impedance does a 1/4-wavelength transmission line present to a generator when the line is shorted at the far end?

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

49. - E9G11

How are the wavelength scales on a Smith chart calibrated?

Select	Answer
A	In fractions of transmission line electrical wavelength
B	In fractions of antenna electrical wavelength
C	In fractions of antenna electrical frequency
D	In fractions of transmission line electrical frequency

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 increasing the number of turns and/or the area
C	By reducing the permeability of the loop shield
D	By utilizing high impedance wire for the coupling loop

Figure E5-1

Figure E7-3

Figure E9-1