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

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1. - E1A08

If a station in a message forwarding system inadvertently forwards a message that is in violation of FCC rules, who is primarily accountable for the rules violation?

Select	Answer
A	The control operators of all the stations in the system
B	The control operator of the packet bulletin board station
C	The control operators of all the stations in the system not authenticating the source from which they accept communications
D	The control operator of the originating station

2. - E1B07

What is the highest modulation index permitted at the highest modulation frequency for angle modulation below 29.0 MHz?

Select	Answer
A	3.0
B	2.0
C	0.5
D	1.0

3. - E1C09

Which of these ranges of frequencies is available for an automatically controlled repeater operating below 30 MHz?

Select	Answer
A	10.100 MHz - 10.150 MHz
B	29.500 MHz - 29.700 MHz
C	18.110 MHz - 18.168 MHz
D	24.940 MHz - 24.990 MHz

4. - E1D06

Which of the following is a requirement of a space station?

Select	Answer
A	The space station must cease all transmissions after 5 years
B	All of these choices are correct
C	The space station must be capable of terminating transmissions by telecommand when directed by the FCC
D	The space station must be capable of changing its orbit whenever such a change is ordered by NASA

5. - E1E05

What is the minimum passing score on amateur operator license examinations?

Select	Answer
A	Minimum passing score of 80%
B	Minimum passing score of 77%
C	Minimum passing score of 74%
D	Minimum passing score of 70%

6. - E1F10

What is the maximum permitted transmitter peak envelope power for an amateur station transmitting spread spectrum communications?

Select	Answer
A	1 W
B	10 W
C	1.5 kW
D	1.5 W

7. - E2A09

What do the terms L band and S band specify with regard to satellite communications?

Select	Answer
A	FM and Digital Store-and-Forward systems
B	The 2 meter and 70 centimeter bands
C	Which sideband to use
D	The 23 centimeter and 13 centimeter bands

8. - E2B16

Which is a video standard used by North American Fast Scan ATV stations?

Select	Answer
A	Scottie
B	DRM
C	NTSC
D	PAL

9. - E2C05

What is the function of a DX QSL Manager?

Select	Answer
A	To run a net to allow many stations to contact a rare DX station
B	To handle the receiving and sending of confirmation cards for a DX station
C	To allocate frequencies for DXpeditions
D	To relay calls to and from a DX station

10. - E2D07

What digital protocol is used by APRS?

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

11. - E2E05

Which type of digital mode does not support keyboard-to-keyboard operation?

Select	Answer
A	MFSK
B	PSK31
C	Winlink
D	RTTY

12. - E3A03

When scheduling EME contacts, which of these conditions will generally result in the least path loss?

Select	Answer
A	When the MUF is above 30 MHz
B	When the Moon is at perigee
C	When the Moon is full
D	When the Moon is at apogee

13. - E3B04

What is meant by the terms extraordinary and ordinary waves?

Select	Answer
A	Long path and short path waves
B	Refracted rays and reflected waves
C	Extraordinary waves describe rare long skip propagation compared to ordinary waves which travel shorter distances
D	Independent waves created in the ionosphere that are elliptically polarized

14. - E3C15

What might a sudden rise in radio background noise indicate?

Select	Answer
A	Increased transequatorial propagation likely
B	Long-path propagation is occurring
C	A solar flare has occurred
D	A meteor ping

15. - E4A10

Which of the following displays multiple digital signal states simultaneously?

Select	Answer
A	Modulation monitor
B	Network analyzer
C	Logic analyzer
D	Bit error rate tester

16. - E4B11

How should an antenna analyzer be connected when measuring antenna resonance and feed point impedance?

Select	Answer
A	Connect the antenna feed line directly to the analyzer's connector
B	Loosely couple the analyzer near the antenna base
C	Connect the analyzer via a high-impedance transformer to the antenna
D	Loosely couple the antenna and a dummy load to the analyzer

17. - E4C01

What is an effect of excessive phase noise in the local oscillator section of a receiver?

Select	Answer
A	It reduces receiver sensitivity
B	It can cause strong signals on nearby frequencies to interfere with reception of weak signals
C	It decreases receiver third-order intermodulation distortion dynamic range
D	It limits the receiver's ability to receive strong signals

18. - E4D14

Which of the following is a way to reduce the likelihood of receiver desensitization?

Select	Answer
A	Raise the receiver IF frequency
B	Decrease the RF bandwidth of the receiver
C	Increase the receiver front end gain
D	Switch from fast AGC to slow AGC

19. - E4E11

Which is the most likely cause if you are hearing combinations of local AM broadcast signals within one or more of the MF or HF ham bands?

Select	Answer
A	Nearby corroded metal joints are mixing and re-radiating the broadcast signals
B	You are receiving sky wave signals from a distant station
C	The broadcast station is transmitting an over-modulated signal
D	Your station receiver IF amplifier stage is defective

20. - E5A13

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

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

21. - E5B03

What happens to the phase angle of a reactance when it is converted to a susceptance?

Select	Answer
A	It is shifted by 90 degrees
B	The sign is reversed
C	It is unchanged
D	The susceptance phase angle is the inverse of the reactance phase angle

22. - E5C15

Which point in Figure E5-2 best represents the impedance of a series circuit consisting of a 300 ohm resistor and an 18 microhenry inductor at 3.505 MHz?

Select	Answer
A	Point 7
B	Point 1
C	Point 3
D	Point 8

23. - E5D03

What is microstrip?

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

24. - E6A15

Which semiconductor material contains excess holes in the outer shell of electrons?

Select	Answer
A	P-type
B	N-type
C	Superconductor-type
D	Bipolar-type

25. - E6B03

What special type of diode is capable of both amplification and oscillation?

Select	Answer
A	Zener
B	Junction
C	Tunnel
D	Point contact

26. - E6C03

What is tri-state logic?

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

27. - E6D08

What is one reason for using powdered-iron cores rather than ferrite cores in an inductor?

Select	Answer
A	Powdered-iron cores use smaller diameter wire for the same inductance
B	Powdered-iron cores generally maintain their characteristics at higher currents
C	Powdered-iron cores generally have greater initial permeability
D	Powdered-iron cores generally require fewer turns to produce a given inductance

28. - E6E12

Why are high-power RF amplifier ICs and transistors sometimes mounted in ceramic packages?

Select	Answer
A	Better dissipation of heat
B	High-voltage insulating ability
C	To provide a low-pass frequency response
D	Enhanced sensitivity to light

29. - E6F02

What happens to the conductivity of a photoconductive material when light shines on it?

Select	Answer
A	It stays the same
B	It becomes unstable
C	It increases
D	It decreases

30. - E7A09

What logical operation is performed by an exclusive NOR gate?

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

31. - E7B12

What type of amplifier circuit is shown in Figure E7-1?

Select	Answer
A	Common collector
B	Common emitter
C	Emitter follower
D	Common base

32. - E7C13

What is one advantage of a Pi-matching network over an L-matching network consisting of a single inductor and a single capacitor?

Select	Answer
A	The Q of Pi-networks can be varied depending on the component values chosen
B	L-networks cannot perform impedance transformation
C	Pi-networks have fewer components
D	Pi-networks are designed for balanced input and output

33. - E7D07

What is the purpose of C2 in the circuit shown in Figure E7-3?

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

34. - E7E09

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

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

35. - E7F03

What type of digital signal processing filter is used to generate an SSB signal?

Select	Answer
A	An elliptical filter
B	A Hilbert-transform filter
C	An adaptive filter
D	A notch filter

36. - E7G05

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

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

37. - E7H11

What are the major spectral impurity components of direct digital synthesizers?

Select	Answer
A	Spurious signals at discrete frequencies
B	Digital conversion noise
C	Broadband noise
D	Nyquist limit noise

38. - E8A11

What type of information can be conveyed using digital waveforms?

Select	Answer
A	All of these choices are correct
B	Video signals
C	Data
D	Human speech

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	1.67
B	60
C	0.167
D	0.6

40. - E8C08

How does ARQ accomplish error correction?

Select	Answer
A	Special binary codes provide automatic correction
B	Special polynomial codes provide automatic correction
C	If errors are detected, a retransmission is requested
D	If errors are detected, redundant data is substituted

41. - E8D04

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

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

42. - 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	6.0 dB
B	8.15 dB
C	3.85 dB
D	2.79 dB

43. - E9B10

What is the principle of a Method of Moments analysis?

Select	Answer
A	A wire is modeled as a series of segments, each having a distinct value of voltage across it
B	A wire is modeled as a series of points, each having a distinct location in space
C	A wire is modeled as a single sine-wave current generator
D	A wire is modeled as a series of segments, each having a uniform value of current

44. - E9C05

What is an OCFD antenna?

Select	Answer
A	A dipole feed approximately 1/3 the way from one end with a 4:1 balun to provide multiband operation
B	A multiband dipole antenna using one-way circular polarization for frequency diversity
C	A remotely tunable dipole antenna using orthogonally controlled frequency diversity
D	An eight band dipole antenna using octophase filters

45. - E9D07

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

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

46. - E9E10

Which of these choices is an effective way to match an antenna with a 100 ohm feed point impedance to a 50 ohm coaxial cable feed line?

Select	Answer
A	Insert a 1/4-wavelength piece of 75 ohm coaxial cable transmission line in series between the antenna terminals and the 50 ohm feed cable
B	Connect 1/2 wavelength shorted stub of 75 ohm cable in parallel with the 50 ohm cable where it attaches to the antenna
C	Insert a 1/2 wavelength piece of 300 ohm twin-lead in series between the antenna terminals and the 50 ohm feed cable
D	Connect a 1/4-wavelength open stub of 300 ohm twin-lead in parallel with the coaxial feed line where it connects to the antenna

47. - E9F08

What is the term for the ratio of the actual speed at which a signal travels through a transmission line to the speed of light in a vacuum?

Select	Answer
A	Characteristic impedance
B	Standing wave ratio
C	Surge impedance
D	Velocity factor

48. - E9G09

What third family of circles is often added to a Smith chart during the process of solving problems?

Select	Answer
A	Coaxial-length circles
B	Radiation-pattern circles
C	Standing wave ratio circles
D	Antenna-length circles

49. - E9H05

What is the main drawback of a wire-loop antenna for direction finding?

Select	Answer
A	It is practical for use only on VHF bands
B	It has a bidirectional pattern
C	It is non-rotatable
D	It receives equally well in all directions

50. - E0A06

Why are there separate electric (E) and magnetic (H) field MPE limits?

Select	Answer
A	The body reacts to electromagnetic radiation from both the E and H fields
B	Ground reflections and scattering make the field impedance vary with location
C	E field and H field radiation intensity peaks can occur at different locations
D	All of these choices are correct

Figure E5-2

Figure E7-1

Figure E7-3