US Amateur Radio - Amateur Extra (Element 4, 2016-2020) Practice Test

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1. - E1A12

With your transceiver displaying the carrier frequency of CW signals, you hear a DX station's CQ on 3.500 MHz. Is it legal to return the call using CW on the same frequency?

Select	Answer
A	Yes, the DX station initiated the contact
B	Yes, the displayed frequency is within the 80 meter CW band segment
C	No, one of the sidebands of the CW signal will be out of the band
D	No, U.S. stations are not permitted to use CW emissions below 3.525 MHz

2. - 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

3. - E1C06

Which of the following statements concerning remotely controlled amateur stations is true?

Select	Answer
A	Only Extra Class operators may be the control operator of a remote station
B	Repeater and auxiliary stations may not be remotely controlled
C	A control operator need not be present at the control point
D	A control operator must be present at the control point

4. - E1D10

Which amateur stations are eligible to be telecommand stations?

Select	Answer
A	All of these choices are correct
B	Any amateur station so designated by the ITU
C	Any amateur station designated by NASA
D	Any amateur station so designated by the space station licensee, subject to the privileges of the class of operator license held by the control operator

5. - E1E03

What is a Volunteer Examiner Coordinator?

Select	Answer
A	A person who has volunteered to prepare amateur operator license examinations
B	A person who has volunteered to administer amateur operator license examinations
C	An organization that has entered into an agreement with the FCC to coordinate amateur operator license examinations
D	The person who has entered into an agreement with the FCC to be the VE session manager

6. - 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 for experimental amateur communications
C	To provide temporary operation while awaiting normal licensing
D	To provide additional spectrum for personal use

7. - E2A08

Why should effective radiated power to a satellite which uses a linear transponder be limited?

Select	Answer
A	To prevent creating errors in the satellite telemetry
B	To avoid interfering with terrestrial QSOs
C	To prevent the satellite from emitting out-of-band signals
D	To avoid reducing the downlink power to all other users

8. - E2B10

Which of the following is an acceptable bandwidth for Digital Radio Mondiale (DRM) based voice or SSTV digital transmissions made on the HF amateur bands?

Select	Answer
A	10 KHz
B	3 KHz
C	20 KHz
D	15 KHz

9. - E2C04

What type of transmission is most often used for a ham radio mesh network?

Select	Answer
A	Store and forward on the 440 MHz band
B	Multiple Frequency Shift Keying in the 10 GHz band
C	Frequency division multiplex in the 24 GHz band
D	Spread spectrum in the 2.4 GHz band

10. - E2D02

Which of the following is a good technique for making meteor scatter contacts?

Select	Answer
A	All of these choices are correct
B	Short transmission with rapidly repeated call signs and signal reports
C	Use of high speed CW or digital modes
D	15 second timed transmission sequences with stations alternating based on location

11. - E2E02

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

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

12. - E3A17

What is meant by circularly polarized electromagnetic waves?

Select	Answer
A	Waves that circle the Earth
B	Waves with an electric field bent into a circular shape
C	Waves with a rotating electric field
D	Waves produced by a loop antenna

13. - E3B14

What happens to linearly polarized radio waves that split into ordinary and extraordinary waves in the ionosphere?

Select	Answer
A	They become phase-locked
B	Their polarization is randomly modified
C	They are bent toward the magnetic poles
D	They become elliptically polarized

14. - E3C14

Why does the radio-path horizon distance exceed the geometric horizon?

Select	Answer
A	E-region skip
B	D-region skip
C	Downward bending due to aurora refraction
D	Downward bending due to density variations in the atmosphere

15. - E4A08

Which of the following instrument would be best for measuring the SWR of a beam antenna?

Select	Answer
A	An ohmmeter
B	A Q meter
C	An antenna analyzer
D	A spectrum analyzer

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

17. - E4C03

What is the term for the blocking of one FM phone signal by another, stronger FM phone signal?

Select	Answer
A	Frequency discrimination
B	Desensitization
C	Cross-modulation interference
D	Capture effect

18. - E4D01

What is meant by the blocking dynamic range of a receiver?

Select	Answer
A	The minimum difference in dB between the levels of two FM signals which will cause one signal to block the other
B	The minimum difference in dB between two signals which produce third order intermodulation products greater than the noise floor
C	The difference in dB between the noise floor and the level of an incoming signal which will cause 1 dB of gain compression
D	The difference in dB between the noise floor and the third order intercept point

19. - E4E16

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

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

20. - E5A12

What is the half-power bandwidth of a parallel resonant circuit that has a resonant frequency of 3.7 MHz and a Q of 118?

Select	Answer
A	15.7 kHz
B	436.6 kHz
C	218.3 kHz
D	31.4 kHz

21. - E5B06

What is susceptance?

Select	Answer
A	The magnetic impedance of a circuit
B	The inverse of reactance
C	A measure of the efficiency of a transformer
D	The ratio of magnetic field to electric field

22. - E5C03

Which of the following represents an inductive reactance in polar coordinates?

Select	Answer
A	A positive real part
B	A negative phase angle
C	A positive phase angle
D	A negative real part

23. - E5D13

How much power is consumed in a circuit consisting of a 100 ohm resistor in series with a 100 ohm inductive reactance drawing 1 ampere?

Select	Answer
A	200 Watts
B	70.7 Watts
C	141.4 Watts
D	100 Watts

24. - E6A13

What do the initials CMOS stand for?

Select	Answer
A	Common Mode Oscillating System
B	Complementary Metal-Oxide Semiconductor
C	Common Mode Organic Silicon
D	Complementary Mica-Oxide Silicon

25. - E6B11

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

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

26. - E6C03

What is tri-state logic?

Select	Answer
A	Logic devices that utilize ternary math
B	Proprietary logic devices manufactured by Tri-State Devices
C	Logic devices with 0, 1, and high impedance output states
D	Low power logic devices designed to operate at 3 volts

27. - E6D01

How many turns will be required to produce a 5-microhenry inductor using a powdered-iron toroidal core that has an inductance index (A L) value of 40 microhenrys/100 turns?

Select	Answer
A	141 turns
B	13 turns
C	35 turns
D	79 turns

28. - E6E10

What is the packaging technique in which leadless components are soldered directly to circuit boards?

Select	Answer
A	Surface mount
B	Stripped lead
C	Direct soldering
D	Virtual lead mounting

29. - E6F07

What is a solid state relay?

Select	Answer
A	A relay using transistors to drive the relay coil
B	A mechanical relay that latches in the on or off state each time it is pulsed
C	A device that uses semiconductors to implement the functions of an electromechanical relay
D	A passive delay line

30. - 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

31. - E7B14

Why are switching amplifiers more efficient than linear amplifiers?

Select	Answer
A	Linear amplifiers have high gain resulting in higher harmonic content
B	Switching amplifiers use push-pull circuits
C	The power transistor is at saturation or cut off most of the time, resulting in low power dissipation
D	Switching amplifiers operate at higher voltages

32. - E7C06

What are the distinguishing features of an elliptical filter?

Select	Answer
A	Extremely flat response over its pass band with gradually rounded stop band corners
B	Gradual passband rolloff with extreme stop band ripple
C	Gradual passband rolloff with minimal stop band ripple
D	Extremely sharp cutoff with one or more notches in the stop band

33. - E7D14

What is one purpose of a "bleeder" resistor in a conventional unregulated power supply?

Select	Answer
A	To boost the amount of output current
B	To improve output voltage regulation
C	To cut down on waste heat generated by the power supply
D	To balance the low-voltage filament windings

34. - E7E09

What occurs when an excessive amount of signal energy reaches a mixer circuit?

Select	Answer
A	Spurious mixer products are generated
B	Mixer blanking occurs
C	Automatic limiting occurs
D	A beat frequency is generated

35. - E7F05

How frequently must an analog signal be sampled by an analog-to-digital converter so that the signal can be accurately reproduced?

Select	Answer
A	At four times the rate of the highest frequency component of the signal
B	At twice the rate of the highest frequency component of the signal
C	At the same rate as the highest frequency component of the signal
D	At half the rate of the highest frequency component of the signal

36. - E7G07

What magnitude of voltage gain can be expected from the circuit in Figure E7-4 when R1 is 10 ohms and RF is 470 ohms?

Select	Answer
A	24
B	47
C	0.21
D	94

37. - E7H10

What information is contained in the lookup table of a direct digital frequency synthesizer?

Select	Answer
A	The phase relationship between a reference oscillator and the output waveform
B	The phase relationship between a voltage-controlled oscillator and the output waveform
C	The amplitude values that represent a sine-wave output
D	The synthesizer frequency limits and frequency values stored in the radio memories

38. - E8A02

What type of wave has a rise time significantly faster than its fall time (or vice versa)?

Select	Answer
A	A cosine wave
B	A sine wave
C	A sawtooth wave
D	A square wave

39. - 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	0.167
C	60
D	1.67

40. - E8C06

What is the necessary bandwidth of a 170-hertz shift, 300-baud ASCII transmission?

Select	Answer
A	0.1 Hz
B	1.0 kHz
C	0.5 kHz
D	0.3 kHz

41. - E8D09

What is considered a good minimum IMD level for an idling PSK signal?

Select	Answer
A	-20 dB
B	+10 dB
C	-30 dB
D	+15 dB

42. - E9A05

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

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

43. - E9B12

What is the far field of an antenna?

Select	Answer
A	The region where radiated power dissipates over a specified time period
B	The region where radiated field strengths are obstructed by objects of reflection
C	The region of the ionosphere where radiated power is not refracted
D	The region where the shape of the antenna pattern is independent of distance

44. - E9C13

What is the main effect of placing a vertical antenna over an imperfect ground?

Select	Answer
A	It changes the impedance angle of the matching network
B	It reduces losses in the radiating portion of the antenna
C	It causes increased SWR
D	It reduces low-angle radiation

45. - E9D10

What happens to feed point impedance at the base of a fixed length HF mobile antenna as the frequency of operation is lowered?

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

46. - E9E02

What is the name of an antenna matching system that matches an unbalanced feed line to an antenna by feeding the driven element both at the center of the element and at a fraction of a wavelength to one side of center?

Select	Answer
A	The stub match
B	The delta match
C	The gamma match
D	The epsilon match

47. - E9F04

What is the typical velocity factor for a coaxial cable with solid polyethylene dielectric?

Select	Answer
A	0.66
B	0.10
C	2.70
D	0.30

48. - E9G03

Which of the following is often determined using a Smith chart?

Select	Answer
A	Trigonometric functions
B	Beam headings and radiation patterns
C	Satellite azimuth and elevation bearings
D	Impedance and SWR values in transmission lines

49. - E9H09

Which of the following describes the construction of a receiving loop antenna?

Select	Answer
A	A vertical antenna coupled to a feed line through an inductive loop of wire
B	A small coil of wire tightly wound around a toroidal ferrite core
C	A large circularly polarized antenna
D	One or more turns of wire wound in the shape of a large open coil

50. - E0A10

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

Select	Answer
A	Polytetrafluroethylene
B	Polychlorinated Biphenyls
C	Polymorphic silicon
D	Polyethylene

Figure E7-4