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. - 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. - E1A13

Who must be in physical control of the station apparatus of an amateur station aboard any vessel or craft that is documented or registered in the United States?

Select	Answer
A	Only a person named in an amateur station license grant
B	Any person holding an FCC issued amateur license or who is authorized for alien reciprocal operation
C	Only a person with an FCC Marine Radio license grant
D	Any person named in an amateur station license grant or a person holding an unrestricted Radiotelephone Operator Permit

3. - E1B03

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

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

4. - E1C14

How long must an operator wait after filing a notification with the Utilities Technology Council (UTC) before operating on the 2200 meter or 630 meter band?

Select	Answer
A	Operators may not operate until a test signal has been transmitted in coordination with the local power company
B	Operators may operate after 30 days, providing they have not been told that their station is within 1 km of PLC systems using those frequencies
C	Operators must not operate until approval is received
D	Operations may commence immediately, and may continue unless interference is reported by the UTC

5. - E1D05

What must be posted at the station location of a station being operated by telecommand on or within 50 km of the earth's surface?

Select	Answer
A	A photocopy of the station license
B	A label with the name, address, and telephone number of the station licensee
C	All these choices are correct
D	A label with the name, address, and telephone number of the control operator

6. - E1E11

What must the VE team do if an examinee scores a passing grade on all examination elements needed for an upgrade or new license?

Select	Answer
A	Three VEs must certify that the examinee is qualified for the license grant and that they have complied with the administering VE requirements
B	Issue the examinee the new or upgrade license
C	All these choices are correct
D	Photocopy all examination documents and forward them to the FCC for processing

7. - E1F04

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

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

8. - E2A02

Which of the following occurs when a satellite is using an inverting linear transponder?

Select	Answer
A	Upper sideband on the uplink becomes lower sideband on the downlink, and vice versa
B	Signal position in the band is reversed
C	All these choices are correct
D	Doppler shift is reduced because the uplink and downlink shifts are in opposite directions

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 provide vertical synchronization
D	To identify the call sign of the station transmitting

10. - E2C09

What type of equipment is commonly used to implement an amateur radio mesh network?

Select	Answer
A	A wireless router running custom firmware
B	A 440 MHz transceiver with a 9600 baud modem
C	An optical cable connection between the USB ports of 2 separate computers
D	A 2 meter VHF transceiver with a 1200 baud modem

11. - E2D10

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

Select	Answer
A	APRS stations with General Personnel Scanners can automatically relay the participant numbers and time as they pass the check points
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	All these choices are correct
D	An APRS station with an emergency medical technician can automatically transmit medical data to the nearest hospital

12. - E2E13

Which of these digital modes has the fastest data throughput under clear communication conditions?

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

13. - E3A13

Which of these emission modes is best for auroral propagation?

Select	Answer
A	RTTY
B	FM
C	CW
D	SSB

14. - E3B12

What is the primary characteristic of chordal hop propagation?

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

15. - E3C07

Which of the following descriptors indicates the greatest solar flare intensity?

Select	Answer
A	Class X
B	Class A
C	Class M
D	Class B

16. - E4A02

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

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

17. - E4B09

What is indicated if the current reading on an RF ammeter placed in series with the antenna feed line of a transmitter increases as the transmitter is tuned to resonance?

Select	Answer
A	There is more power going into the antenna
B	There is an impedance mismatch between the antenna and feed line
C	The transmitter is not properly neutralized
D	There is possibly a short to ground in the feed line

18. - E4C08

An SDR receiver is overloaded when input signals exceed what level?

Select	Answer
A	One-half the maximum sampling buffer size
B	The maximum count value of the analog-to-digital converter
C	One-half the maximum sample rate
D	The reference voltage of the analog-to-digital converter

19. - E4D11

Why are odd-order intermodulation products, created within a receiver, of particular interest compared to other products?

Select	Answer
A	Odd-order intermodulation produces three products for every input signal within the band of interest
B	Odd-order products overload the IF filters
C	Odd-order products are an indication of poor image rejection
D	Odd-order products of two signals in the band of interest are also likely to be within the band

20. - E4E03

Which of the following signals might a receiver noise blanker be able to remove from desired signals?

Select	Answer
A	Signals that have a sharply peaked frequency distribution
B	Signals that appear at one IF but not another
C	Signals that are constant at all IF levels
D	Signals that appear across a wide bandwidth

21. - E5A07

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

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

22. - E5B12

What is admittance?

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

23. - E5C05

What is the name of the diagram used to show the phase relationship between impedances at a given frequency?

Select	Answer
A	Far field diagram
B	Venn diagram
C	Near field diagram
D	Phasor diagram

24. - E5D01

What is the result of skin effect?

Select	Answer
A	As frequency decreases, RF current flows in a thinner layer of the conductor, closer to the surface
B	As frequency increases, RF current flows in a thinner layer of the conductor, closer to the surface
C	Thermal effects on the surface of the conductor increase the impedance
D	Thermal effects on the surface of the conductor decrease the impedance

25. - E6A04

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

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

26. - E6B08

Which of the following is a Schottky barrier diode?

Select	Answer
A	Electrolytic rectifier
B	Metal-semiconductor junction
C	PIN junction
D	Thermionic emission diode

27. - E6C10

In Figure E6-3, what is the schematic symbol for a NOR gate?

Select	Answer
A	2
B	1
C	4
D	3

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

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	50 ohms
D	10 ohms

30. - E6F06

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

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

31. - E7A01

Which circuit is bistable?

Select	Answer
A	A flip-flop
B	An OR gate
C	A bipolar amplifier
D	An AND gate

32. - E7B18

What is a characteristic of a grounded-grid amplifier?

Select	Answer
A	High power gain
B	Low bandwidth
C	High filament voltage
D	Low input impedance

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	Two capacitors are in series between the input and output, and an inductor is connected between the two capacitors and ground
B	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
C	Two inductors are in series between the input and output, and a capacitor is connected between the two inductors and ground
D	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

34. - E7D07

What is the purpose of C2 in the circuit shown in Figure E7-2?

Select	Answer
A	To self-resonate at the hum frequency
B	It bypasses rectifier output ripple around D1
C	It is a brute force filter for the output
D	To provide fixed DC bias for Q1

35. - E7E08

What are the principal frequencies that appear at the output of a mixer circuit?

Select	Answer
A	The two input frequencies along with their sum and difference frequencies
B	Two and four times the original frequency
C	1.414 and 0.707 times the input frequency
D	The square root of the product of input frequencies

36. - E7F12

Which of the following is an advantage of a Finite Impulse Response (FIR) filter vs an Infinite Impulse Response (IIR) digital filter?

Select	Answer
A	FIR filters can respond faster to impulses
B	FIR filters are easier to implement for a given set of passband rolloff requirements
C	All these choices are correct
D	FIR filters can delay all frequency components of the signal by the same amount

37. - E7G05

How can unwanted ringing and audio instability be prevented in an op-amp RC audio filter circuit?

Select	Answer
A	Restrict Q but increase gain
B	Restrict gain but increase Q
C	Restrict both gain and Q
D	Increase both gain and Q

38. - E7H07

How can an oscillator's microphonic responses be reduced?

Select	Answer
A	Mechanically isolate the oscillator circuitry from its enclosure
B	Use NP0 capacitors
C	Reduce noise on the oscillator's power supply
D	Increase the bias voltage

39. - E8A06

What is the approximate ratio of PEP-to-average power in a typical single-sideband phone signal?

Select	Answer
A	25 to 1
B	100 to 1
C	2.5 to 1
D	1 to 1

40. - E8B10

What is frequency division multiplexing?

Select	Answer
A	The transmitted signal jumps from band to band at a predetermined rate
B	Two or more information streams are merged into a digital combiner, which then pulse position modulates the transmitter
C	The transmitted signal is divided into packets of information
D	Two or more information streams are merged into a baseband, which then modulates the transmitter

41. - E8C09

Which digital code allows only one bit to change between sequential code values?

Select	Answer
A	Extended Binary Coded Decimal Interchange Code
B	Excess 3 code
C	Binary Coded Decimal Code
D	Gray code

42. - E8D04

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

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

43. - E9A03

What is the radiation resistance of an antenna?

Select	Answer
A	The resistance in the atmosphere that an antenna must overcome to be able to radiate a signal
B	The specific impedance of the antenna
C	The combined losses of the antenna elements and feed line
D	The value of a resistance that would dissipate the same amount of power as that radiated from an antenna

44. - E9B01

In the antenna radiation pattern shown in Figure E9-1, what is the beamwidth?

Select	Answer
A	25 degrees
B	50 degrees
C	30 degrees
D	75 degrees

45. - E9C01

What is the radiation pattern of two 1/4-wavelength vertical antennas spaced 1/2-wavelength apart and fed 180 degrees out of phase?

Select	Answer
A	Cardioid
B	A figure-8 broadside to the axis of the array
C	Omni-directional
D	A figure-8 oriented along the axis of the array

46. - E9D05

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

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

47. - E9E04

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

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

48. - E9F04

What impedance does a 1/2-wavelength transmission line present to a generator when the line is shorted at the far end?

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

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	Reactance axis
B	Prime axis
C	Polar axis
D	Impedance axis

50. - E9H08

What is the function of a sense antenna?

Select	Answer
A	It modifies the pattern of a DF antenna array to provide a null in one direction
B	It increases the sensitivity of a DF antenna array
C	It provides diversity reception that cancels multipath signals
D	It allows DF antennas to receive signals at different vertical angles

Figure E6-3

Figure E7-2

Figure E9-1

Figure E9-3