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

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1. - E0A03

Over what range of frequencies are the FCC human body RF exposure limits most restrictive?

Select	Answer
A	300 to 3000 MHz
B	30 to 300 MHz
C	3 to 30 MHz
D	300 kHz to 3 MHz

2. - E1A11

Which of the following describes authorization or licensing required when operating an amateur station aboard a U.S.-registered vessel in international waters?

Select	Answer
A	Only General Class or higher amateur licenses
B	Any FCC-issued amateur license
C	An unrestricted Radiotelephone Operator Permit
D	Any amateur license with an FCC Marine or Aircraft endorsement

3. - E1B04

What must be done before placing an amateur station within an officially designated wilderness area or wildlife preserve, or an area listed in the National Register of Historic Places?

Select	Answer
A	An Environmental Assessment must be submitted to the FCC
B	A proposal must be submitted to the National Park Service
C	A form FSD-15 must be submitted to the Department of the Interior
D	A letter of intent must be filed with the Environmental Protection Agency

4. - E1C03

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

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

5. - E1D12

Which of the following amateur stations may transmit one-way communications?

Select	Answer
A	A local repeater or linked repeater station
B	All these choices are correct
C	A message forwarding station or automatically controlled digital station
D	A space station, beacon station, or telecommand station

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	Teaching an amateur operator license examination preparation course
C	Preparing, processing, administering, and coordinating an examination for an amateur radio operator license
D	Providing amateur operator license examination preparation training materials

7. - E1F02

What privileges are authorized in the U.S. to persons holding an amateur service license granted by the government of Canada?

Select	Answer
A	None, they must obtain a U.S. license
B	All privileges of the Amateur Extra Class license
C	Full privileges, up to and including those of the Amateur Extra Class license, on the 80, 40, 20, 15, and 10 meter bands
D	The operating terms and conditions of the Canadian amateur service license, not to exceed U.S. Amateur Extra Class license privileges

8. - E2A05

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

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

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

10. - E2C06

During a VHF/UHF contest, in which band segment would you expect to find the highest level of SSB or CW activity?

Select	Answer
A	In the middle of each band, usually on the national calling frequency
B	In the weak signal segment of the band, with most of the activity near the calling frequency
C	In the middle of the band, usually 25 kHz above the national calling frequency
D	At the top of each band, usually in a segment reserved for contests

11. - E2D10

How can an APRS station be used to help support a public service communications activity?

Select	Answer
A	All these choices are correct
B	An APRS station with a Global Positioning System unit can automatically transmit information to show a mobile station's position during the event
C	An APRS station with an emergency medical technician can automatically transmit medical data to the nearest hospital
D	APRS stations with General Personnel Scanners can automatically relay the participant numbers and time as they pass the check points

12. - E2E05

Which of these digital modes does not support keyboard-to-keyboard operation?

Select	Answer
A	PSK31
B	MFSK
C	RTTY
D	PACTOR

13. - E3A01

What is the approximate maximum separation measured along the surface of the Earth between two stations communicating by EME?

Select	Answer
A	5000 miles, if the moon is at perigee
B	12,000 miles, if the moon is visible by both stations
C	500 miles, if the moon is at perigee
D	2000 miles, if the moon is at apogee

14. - E3B06

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

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

15. - E3C12

How does the maximum range of ground-wave propagation change when the signal frequency is increased?

Select	Answer
A	It stays the same
B	It decreases
C	It peaks at roughly 14 MHz
D	It increases

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

17. - E4B08

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

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

18. - E4C07

What does the MDS of a receiver represent?

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

19. - E4D10

What does a third-order intercept level of 40 dBm mean with respect to receiver performance?

Select	Answer
A	The receiver can tolerate signals up to 40 dB above the noise floor without producing third-order intermodulation products
B	A pair of 1 mW input signals will produce a third-order intermodulation product that is 40 dB stronger than the input signal
C	A pair of 40 dBm input signals will theoretically generate a third-order intermodulation product that has the same output amplitude as either of the input signals
D	Signals less than 40 dBm will not generate audible third-order intermodulation products

20. - E4E04

How can conducted and radiated noise caused by an automobile alternator be suppressed?

Select	Answer
A	By installing filter capacitors in series with the DC power lead and a blocking capacitor in the field lead
B	By installing a high-pass filter in series with the radio's power lead and a low-pass filter in parallel with the field lead
C	By connecting the radio's power leads directly to the battery and by installing coaxial capacitors in line with the alternator leads
D	By installing a noise suppression resistor and a blocking capacitor in both leads

21. - E5A11

What is the half-power bandwidth of a resonant circuit that has a resonant frequency of 7.1 MHz and a Q of 150?

Select	Answer
A	315.6 Hz
B	157.8 Hz
C	23.67 kHz
D	47.3 kHz

22. - E5B10

What is the relationship between the AC current through an inductor and the voltage across an inductor?

Select	Answer
A	Voltage leads current by 90 degrees
B	Current leads voltage by 90 degrees
C	Voltage and current are 180 degrees out of phase
D	Voltage and current are in 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	Polar coordinates
B	Faraday grid
C	Maidenhead grid
D	Elliptical coordinates

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	1000 watts
C	600 watts
D	1600 watts

25. - E6A07

Which of the following indicates that a silicon NPN junction transistor is biased on?

Select	Answer
A	Base-to-emitter resistance of approximately 0.6 to 0.7 ohms
B	Base-to-emitter voltage of approximately 0.6 to 0.7 volts
C	Base-to-emitter voltage of approximately 6 to 7 volts
D	Base-to-emitter resistance of approximately 6 to 7 ohms

26. - E6B05

What characteristic of a PIN diode makes it useful as an RF switch?

Select	Answer
A	Ability to dissipate large amounts of power
B	Low junction capacitance
C	Extremely high reverse breakdown voltage
D	Reverse bias controls its forward voltage drop

27. - E6C07

What best describes a pull-up or pull-down resistor?

Select	Answer
A	A resistor connected to the positive or negative supply line used to establish a voltage when an input or output is an open circuit
B	A resistor that ensures that an oscillator frequency does not drift
C	A resistor connected to an op-amp output that prevents signals from exceeding the power supply voltage
D	A resistor in a keying circuit used to reduce key clicks

28. - E6D12

What is inductor saturation?

Select	Answer
A	Adjacent inductors become over-coupled
B	The inductor windings are over-coupled
C	The ability of the inductor's core to store magnetic energy has been exceeded
D	The inductor's voltage rating is exceeded causing a flashover

29. - E6E02

Which of the following device packages is a through-hole type?

Select	Answer
A	PLCC
B	DIP
C	Ball grid array
D	SOT

30. - E6F08

Why are optoisolators often used in conjunction with solid-state circuits when switching 120 VAC?

Select	Answer
A	Optoisolators provide a low impedance link between a control circuit and a power circuit
B	Optoisolators eliminate the effects of reflected light in the control circuit
C	Optoisolators provide impedance matching between the control circuit and power circuit
D	Optoisolators provide a very high degree of electrical isolation between a control circuit and the circuit being switched

31. - E7A07

What logical operation does a NAND gate perform?

Select	Answer
A	It produces logic 0 at its output only when all inputs are logic 0
B	It produces logic 0 at its output only when all inputs are logic 1
C	It produces logic 1 at its output only when all inputs are logic 1
D	It produces logic 0 at its output if some but not all inputs are logic 1

32. - E7B13

Which of the following describes an emitter follower (or common collector) amplifier?

Select	Answer
A	A differential amplifier with both inputs fed to the emitter of the input transistor
B	An OR circuit with only one emitter used for output
C	An amplifier with a low impedance output that follows the base input voltage
D	A two-transistor amplifier with the emitters sharing a common bias resistor

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

34. - E7D09

What is the main reason to use a charge controller with a solar power system?

Select	Answer
A	Matching of day and night charge rates
B	Control of electrolyte levels during battery discharge
C	Prevention of battery undercharge
D	Prevention of battery damage due to overcharge

35. - E7E02

What is the function of a reactance modulator?

Select	Answer
A	To produce AM signals by using an electrically variable resistance
B	To produce PM signals by using an electrically variable resistance
C	To produce AM signals by using an electrically variable inductance or capacitance
D	To produce PM or FM signals by using an electrically variable inductance or capacitance

36. - E7F09

Why is an anti-aliasing digital filter required in a digital decimator?

Select	Answer
A	It removes low-frequency signal components to eliminate the need for DC restoration
B	It notches out the sampling frequency to avoid sampling errors
C	It peaks the response of the decimator, improving bandwidth
D	It removes high-frequency signal components that would otherwise be reproduced as lower frequency components

37. - E7G03

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

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

38. - E7H01

What are three oscillator circuits used in amateur radio equipment?

Select	Answer
A	Colpitts, Hartley and Pierce
B	Taft, Hartley and Pierce
C	Pierce, Fenner and Beane
D	Taft, Pierce and negative feedback

39. - E8A11

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

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

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	3
B	2000
C	6000
D	1/3

41. - E8C03

Why should phase-shifting of a PSK signal be done at the zero crossing of the RF signal?

Select	Answer
A	All these choices are correct
B	To improve carrier suppression
C	To minimize bandwidth
D	To simplify modulation

42. - E8D08

What parameter evaluates distortion of an AFSK signal caused by excessive input audio levels?

Select	Answer
A	Baud rate
B	Intermodulation Distortion (IMD)
C	Repeat Request Rate (RRR)
D	Signal-to-noise ratio

43. - E9A08

What is antenna bandwidth?

Select	Answer
A	Antenna length divided by the number of elements
B	The frequency range over which an antenna satisfies a performance requirement
C	The angle formed between two imaginary lines drawn through the element ends
D	The angle between the half-power radiation points

44. - E9B05

What type of antenna pattern is shown in Figure E9-2?

Select	Answer
A	Radiation resistance
B	Polarization
C	Elevation
D	Azimuth

45. - E9C06

What is the effect of adding a terminating resistor to a rhombic antenna?

Select	Answer
A	It changes the radiation pattern from bidirectional to unidirectional
B	It decreases the ground loss
C	It changes the radiation pattern from horizontal to vertical polarization
D	It reflects the standing waves on the antenna elements back to the transmitter

46. - E9D10

What happens to feed-point impedance at the base of a fixed length HF mobile antenna when operated below its resonant frequency?

Select	Answer
A	The radiation resistance decreases and the capacitive reactance decreases
B	The radiation resistance increases and the capacitive reactance decreases
C	The radiation resistance decreases and the capacitive reactance increases
D	The radiation resistance increases and the capacitive reactance increases

47. - E9E07

What parameter describes the interactions at the load end of a mismatched transmission line?

Select	Answer
A	Characteristic impedance
B	Velocity factor
C	Dielectric constant
D	Reflection coefficient

48. - E9F07

How does ladder line compare to small-diameter coaxial cable such as RG-58 at 50 MHz?

Select	Answer
A	Lower loss
B	Smaller reflection coefficient
C	Lower velocity factor
D	Higher SWR

49. - E9G11

How are the wavelength scales on a Smith chart calibrated?

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

50. - E9H07

Why is RF attenuation used when direction-finding?

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

Figure E9-2