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

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1. - E0A11

Which of the following injuries can result from using high-power UHF or microwave transmitters?

Select	Answer
A	Hearing loss caused by high voltage corona discharge
B	Ingestion of ozone gas from the cooling system
C	Localized heating of the body from RF exposure in excess of the MPE limits
D	Blood clotting from the intense magnetic field

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

3. - E1B01

Which of the following constitutes a spurious emission?

Select	Answer
A	Any transmitted signal that unintentionally interferes with another licensed radio station
B	An emission outside the signal's necessary bandwidth that can be reduced or eliminated without affecting the information transmitted
C	An amateur station transmission made without the proper call sign identification
D	A signal transmitted to prevent its detection by any station other than the intended recipient

4. - E1C11

Which of the following operating arrangements allows an FCC-licensed U.S. citizen to operate in many European countries, and alien amateurs from many European countries to operate in the U.S.?

Select	Answer
A	IARP agreement
B	CEPT agreement
C	All these choices are correct
D	ITU reciprocal license

5. - E1D06

What is the maximum permitted transmitter output power when operating a model craft by telecommand?

Select	Answer
A	5 watts
B	1 watt
C	2 watts
D	100 watts

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. - E1F06

Under what circumstances might the FCC issue a Special Temporary Authority (STA) to an amateur station?

Select	Answer
A	To allow regular operation on Land Mobile channels
B	To provide temporary operation while awaiting normal licensing
C	To provide for experimental amateur communications
D	To provide additional spectrum for personal use

8. - E2A10

What type of satellite appears to stay in one position in the sky?

Select	Answer
A	HEO
B	Geomagnetic
C	Geostationary
D	LEO

9. - E2B03

How is an interlaced scanning pattern generated in a fast-scan (NTSC) television system?

Select	Answer
A	By scanning two fields simultaneously
B	By scanning each field from bottom to top
C	By scanning odd numbered lines in one field and even numbered lines in the next
D	By scanning lines from left to right in one field and right to left in the next

10. - E2C11

How should you generally identify your station when attempting to contact a DX station during a contest or in a pileup?

Select	Answer
A	Send your full call sign and grid square
B	Send only the last two letters of your call sign until you make contact
C	Send your full call sign once or twice
D	Send the call sign of the DX station three times, the words this is,then your call sign three times

11. - E2D09

What type of modulation is used for JT65 contacts?

Select	Answer
A	RTTY
B	Multi-tone AFSK
C	IEEE 802.11
D	PSK

12. - E2E02

What do the letters FEC mean as they relate to digital operation?

Select	Answer
A	Fatal Error Correction
B	First Error Correction
C	Forward Error Correction
D	Final Error Correction

13. - E3A01

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

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

14. - E3B06

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

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

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

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

17. - E4B06

How much power is being absorbed by the load when a directional power meter connected between a transmitter and a terminating load reads 100 watts forward power and 25 watts reflected power?

Select	Answer
A	75 watts
B	25 watts
C	100 watts
D	125 watts

18. - E4C01

What is an effect of excessive phase noise in a receiver's local oscillator?

Select	Answer
A	It can affect the receiver's frequency calibration
B	It decreases receiver third-order intercept point
C	It can combine with strong signals on nearby frequencies to generate interference
D	It limits the receiver's ability to receive strong signals

19. - E4D11

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

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

20. - E4E08

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

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

21. - E5A09

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

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

22. - E5B02

What letter is commonly used to represent susceptance?

Select	Answer
A	B
B	X
C	Y
D	G

23. - E5C07

Where is the impedance of a pure resistance plotted on rectangular coordinates?

Select	Answer
A	On a line through the origin, slanted at 45 degrees
B	On the horizontal axis
C	On the vertical axis
D	On a horizontal line, offset vertically above the horizontal axis

24. - E5D06

In what direction is the magnetic field oriented about a conductor in relation to the direction of electron flow?

Select	Answer
A	In the same direction as the current
B	In all directions; omni-directional
C	In a circle around the conductor
D	In a direction opposite to the current

25. - E6A04

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

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

26. - E6B02

What is an important characteristic of a Schottky diode as compared to an ordinary silicon diode when used as a power supply rectifier?

Select	Answer
A	Less forward voltage drop
B	Much higher reverse voltage breakdown
C	Longer carrier retention time
D	More constant reverse avalanche voltage

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

28. - E6D07

What is current in the primary winding of a transformer called if no load is attached to the secondary?

Select	Answer
A	Direct current
B	Excitation current
C	Magnetizing current
D	Stabilizing current

29. - E6E04

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

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

30. - E6F01

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

Select	Answer
A	Photons
B	Electrons
C	Holes
D	Protons

31. - E7A11

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

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

32. - E7B09

Which of the following describes how the loading and tuning capacitors are to be adjusted when tuning a vacuum tube RF power amplifier that employs a Pi-network output circuit?

Select	Answer
A	The tuning capacitor is set to maximum capacitance and the loading capacitor is adjusted for minimum plate permissible current
B	The loading capacitor is set to maximum capacitance and the tuning capacitor is adjusted for minimum allowable plate current
C	The loading capacitor is adjusted to minimum plate current while alternately adjusting the tuning capacitor for maximum allowable plate current
D	The tuning capacitor is adjusted for minimum plate current, and the loading capacitor is adjusted for maximum permissible plate current

33. - E7C03

What advantage does a series-L Pi-L-network have over a series-L Pi-network for impedance matching between the final amplifier of a vacuum-tube transmitter and an antenna?

Select	Answer
A	Higher efficiency
B	Greater transformation range
C	Greater harmonic suppression
D	Does not require a capacitor

34. - E7D07

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

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

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 rectification and filtering of RF signals
C	By sensing the change of reactance in the diode with respect to frequency
D	By breakdown of the Zener voltage

36. - E7F09

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

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

37. - E7G06

What is the gain-bandwidth of an operational amplifier?

Select	Answer
A	The maximum frequency for a filter circuit using that type of amplifier
B	The frequency at which the open-loop gain of the amplifier equals one
C	The gain of the amplifier at a filter's cutoff frequency
D	The frequency at which the amplifier's offset voltage is zero

38. - E7H06

Which of the following oscillator circuits are commonly used in VFOs?

Select	Answer
A	Negative feedback and balanced feedback
B	Armstrong and deForest
C	Pierce and Zener
D	Colpitts and Hartley

39. - E8A10

What is the purpose of a low-pass filter used in conjunction with a digital-to-analog converter?

Select	Answer
A	Remove harmonics from the output caused by the discrete analog levels generated
B	All these choices are correct
C	Lower the input bandwidth to increase the effective resolution
D	Improve accuracy by removing out-of-sequence codes from the input

40. - E8B10

What is frequency division multiplexing?

Select	Answer
A	The transmitted signal is divided into packets of information
B	The transmitted signal jumps from band to band at a predetermined rate
C	Two or more information streams are merged into a digital combiner, which then pulse position modulates the transmitter
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	Excess 3 code
B	Binary Coded Decimal Code
C	Extended Binary Coded Decimal Interchange 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	The generation of RF harmonics
C	More difficult to copy
D	Limits data speed

43. - E9A05

What is included in the total resistance of an antenna system?

Select	Answer
A	Radiation resistance plus transmission resistance
B	Transmission-line resistance plus radiation resistance
C	Radiation resistance plus space impedance
D	Radiation resistance plus loss resistance

44. - E9B06

What is the elevation angle of peak response in the antenna radiation pattern shown in Figure E9-2?

Select	Answer
A	25 degrees
B	7.5 degrees
C	45 degrees
D	75 degrees

45. - E9C11

How is the far-field elevation pattern of a vertically polarized antenna affected by being mounted over seawater versus soil?

Select	Answer
A	The low-angle radiation decreases
B	Additional higher vertical angle lobes will appear
C	The low-angle radiation increases
D	Fewer vertical angle lobes will be present

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

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 stub match
B	The delta match
C	The gamma match
D	The omega match

48. - E9F11

What impedance does a 1/8-wavelength transmission line present to a generator when the line is open at the far end?

Select	Answer
A	A capacitive reactance
B	An inductive reactance
C	The same as the characteristic impedance of the line
D	Infinite

49. - E9G10

What do the arcs on a Smith chart represent?

Select	Answer
A	Frequency
B	Points with constant reactance
C	Points with constant resistance
D	SWR

50. - E9H11

What feature of a cardioid pattern antenna makes it useful for direction finding?

Select	Answer
A	High radiation angle
B	A very sharp peak
C	A very sharp single null
D	Broadband response

Figure E7-2

Figure E9-2