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

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1. - E1A06

Where must the carrier frequency of a CW signal be set to comply with FCC rules for 60 meter operation?

Select	Answer
A	At the lowest frequency of the channel
B	At the center frequency of the channel
C	On any frequency where the signal's sidebands are within the channel
D	At the highest frequency of the channel

2. - E1B11

What is the permitted mean power of any spurious emission relative to the mean power of the fundamental emission from a station transmitter or external RF amplifier installed after January 1, 2003 and transmitting on a frequency below 30 MHZ?

Select	Answer
A	At least 53 dB below
B	At least 43 dB below
C	At least 63 dB below
D	At least 73 dB below

3. - E1C09

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

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

4. - E1D05

What class of licensee is authorized to be the control operator of a space station?

Select	Answer
A	All except Technician Class
B	Only Amateur Extra Class
C	Only General, Advanced or Amateur Extra Class
D	Any class with appropriate operator privileges

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 70%
C	Minimum passing score of 77%
D	Minimum passing score of 74%

6. - E1F09

Which of the following conditions apply when transmitting spread spectrum emission?

Select	Answer
A	A station transmitting SS emission must not cause harmful interference to other stations employing other authorized emissions
B	The transmitting station must be in an area regulated by the FCC or in a country that permits SS emissions
C	All of these choices are correct
D	The transmission must not be used to obscure the meaning of any communication

7. - E2A04

What is meant by the term mode as applied to an amateur radio satellite?

Select	Answer
A	The satellite's uplink and downlink frequency bands
B	The type of signals that can be relayed through the satellite
C	Whether the satellite is in a polar or equatorial orbit
D	The satellite's orientation with respect to the Earth

8. - E2B11

What is the function of the Vertical Interval Signaling (VIS) code sent as part of an SSTV transmission?

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

9. - E2C13

What indicator is required to be used by U.S.-licensed operators when operating a station via remote control where the transmitter is located in the U.S.?

Select	Answer
A	/R# where # is the district of the remote station
B	/ followed by the USPS two letter abbreviation for the state in which the remote station is located
C	No additional indicator is required
D	The ARRL section of the remote station

10. - E2D13

What type of modulation is used for JT65 contacts?

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

11. - E2E03

How is the timing of JT65 contacts organized?

Select	Answer
A	Stations take turns on alternate days
B	Alternating transmissions at 1 minute intervals
C	By exchanging ACK/NAK packets
D	It depends on the lunar phase

12. - E3A04

What do Hepburn maps predict?

Select	Answer
A	Sporadic E propagation
B	Likelihood of rain-scatter along cold or warm fronts
C	Probability of tropospheric propagation
D	Locations of auroral reflecting zones

13. - E3B06

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

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

14. - E3C05

What orientation of Bz (B sub z) increases the likelihood that incoming particles from the Sun will cause disturbed conditions?

Select	Answer
A	Eastward
B	Southward
C	Westward
D	Northward

15. - E4A05

What might be an advantage of a digital vs an analog oscilloscope?

Select	Answer
A	Automatic amplitude and frequency numerical readout
B	Manipulation of time base after trace capture
C	Storage of traces for future reference
D	All of these choices are correct

16. - E4B13

Which S parameter is equivalent to forward gain?

Select	Answer
A	S11
B	S22
C	S12
D	S21

17. - E4C04

How is the noise figure of a receiver defined?

Select	Answer
A	The ratio of atmospheric noise to phase noise
B	The ratio of thermal noise to atmospheric noise
C	The ratio of the noise bandwidth in Hertz to the theoretical bandwidth of a resistive network
D	The ratio in dB of the noise generated by the receiver to the theoretical minimum noise

18. - E4D14

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

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

19. - E4E15

Which of the following can cause shielded cables to radiate or receive interference?

Select	Answer
A	Use of braided shielding material
B	Low inductance ground connections at both ends of the shield
C	Tying all ground connections to a common point resulting in differential mode currents in the shield
D	Common mode currents on the shield and conductors

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	218.3 kHz
C	436.6 kHz
D	31.4 kHz

21. - E5B12

What is admittance?

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

22. - E5C03

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

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

23. - E5D07

What determines the strength of the magnetic field around a conductor?

Select	Answer
A	The ratio of the current to the resistance
B	The diameter of the conductor
C	The resistance divided by the current
D	The amount of current flowing through the conductor

24. - E6A07

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

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

25. - 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	Controlled reverse avalanche voltage
C	Much higher reverse voltage breakdown
D	Enhanced carrier retention time

26. - E6C12

What is BiCMOS logic?

Select	Answer
A	A logic family based on bismuth CMOS devices
B	A logic device with two CMOS circuits per package
C	An integrated circuit logic family using both bipolar and CMOS transistors
D	A FET logic family based on bimetallic semiconductors

27. - E6D15

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

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

28. - E6E02

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

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

29. - E6F14

Which of the following is true of LCD displays?

Select	Answer
A	They only display alphanumeric symbols
B	They may be hard view through polarized lenses
C	They are hard to view in high ambient light conditions
D	All of these choices are correct

30. - E7A11

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

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

31. - E7B11

In Figure E7-1, what is the purpose of R3?

Select	Answer
A	Output load resistor
B	Self bias
C	Fixed bias
D	Emitter bypass

32. - E7C07

What kind of filter would you use to attenuate an interfering carrier signal while receiving an SSB transmission?

Select	Answer
A	A Pi-network filter
B	A band-pass filter
C	A notch filter
D	An all-pass filter

33. - E7D09

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

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

34. - E7E10

How does a diode detector function?

Select	Answer
A	By mixing signals with noise in the transition region of the diode
B	By breakdown of the Zener voltage
C	By sensing the change of reactance in the diode with respect to frequency
D	By rectification and filtering of RF signals

35. - E7F14

Which of the following would allow a digital signal processing filter to create a sharper filter response?

Select	Answer
A	More taps
B	Complex phasor representations
C	Higher data rate
D	Double-precision math routines

36. - E7G08

How does the gain of an ideal operational amplifier vary with frequency?

Select	Answer
A	It decreases linearly with increasing frequency
B	It increases linearly with increasing frequency
C	It decreases logarithmically with increasing frequency
D	It does not vary with frequency

37. - E7H06

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

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

38. - E8A08

Why would a direct or flash conversion analog-to-digital converter be useful for a software defined radio?

Select	Answer
A	Very high speed allows digitizing high frequencies
B	All of these choices are correct
C	Immunity to out of sequence coding reduces spurious responses
D	Very low power consumption decreases frequency drift

39. - E8B02

How does the modulation index of a phase-modulated emission vary with RF carrier frequency (the modulated frequency)?

Select	Answer
A	It varies with the square root of the RF carrier frequency
B	It decreases as the RF carrier frequency increases
C	It increases as the RF carrier frequency increases
D	It does not depend on the RF carrier frequency

40. - E8C02

What is the definition of symbol rate in a digital transmission?

Select	Answer
A	The number of characters carried per second by the station-to-station link
B	The duration of each bit in a message sent over the air
C	The number of control characters in a message packet
D	The rate at which the waveform of a transmitted signal changes to convey information

41. - E8D10

What are some of the differences between the Baudot digital code and ASCII?

Select	Answer
A	Baudot uses 6 data bits per character, ASCII uses 7 or 8; Baudot has no letters/figures shift code, ASCII uses 2 letters/figures shift codes
B	Baudot uses 5 data bits per character, ASCII uses 7 or 8; Baudot uses 2 characters as letters/figures shift codes, ASCII has no letters/figures shift code
C	Baudot uses 4 data bits per character, ASCII uses 7 or 8; Baudot uses 1 character as a letters/figures shift code, ASCII has no letters/figures code
D	Baudot uses 7 data bits per character, ASCII uses 8; Baudot has no letters/figures shift code, ASCII uses 2 letters/figures shift codes

42. - E9A10

Which of the following choices is a way to improve the efficiency of a ground-mounted quarter-wave vertical antenna?

Select	Answer
A	Install a good radial system
B	Shorten the radiating element
C	Isolate the coax shield from ground
D	Reduce the diameter of the radiating element

43. - E9B16

How many elevation lobes appear in the forward direction of the antenna radiation pattern shown in Figure E9-2?

Select	Answer
A	4
B	1
C	3
D	7

44. - E9C09

What is a G5RV antenna?

Select	Answer
A	A phased array antenna consisting of multiple loops
B	A multi-band dipole antenna fed with coax and a balun through a selected length of open wire transmission line
C	A wide band dipole using shorted coaxial cable for the radiating elements and fed with a 4:1 balun
D	A multi-band trap antenna

45. - E9D12

Which of the following would provide the best RF ground for your station?

Select	Answer
A	A 50 ohm resistor connected to ground
B	An electrically short connection to 3 or 4 interconnected ground rods via a series RF choke
C	An electrically short connection to 3 or 4 interconnected ground rods driven into the Earth
D	An electrically short connection to a metal water pipe

46. - E9E07

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

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

47. - E9F10

What impedance does a 1/8 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	An inductive reactance
C	A capacitive reactance
D	The same as the input impedance to the final generator stage

48. - E9G01

Which of the following can be calculated using a Smith chart?

Select	Answer
A	Radio propagation
B	Radiation resistance
C	Impedance along transmission lines
D	Antenna radiation pattern

49. - E9H08

What is the function of a sense antenna?

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

50. - E0A04

When evaluating a site with multiple transmitters operating at the same time, the operators and licensees of which transmitters are responsible for mitigating over-exposure situations?

Select	Answer
A	Only the most powerful transmitter
B	Each transmitter that produces 5 percent or more of its MPE limit at accessible locations
C	Only commercial transmitters
D	Each transmitter operating with a duty-cycle greater than 50 percent

Figure E7-1

Figure E9-2