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

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1. - E1A09

What is the first action you should take if your digital message forwarding station inadvertently forwards a communication that violates FCC rules?

Select	Answer
A	Discontinue forwarding the communication as soon as you become aware of it
B	Discontinue forwarding all messages
C	Notify the nearest FCC Field Engineer's office
D	Notify the originating station that the communication does not comply with FCC rules

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 43 dB below
B	At least 53 dB below
C	At least 73 dB below
D	At least 63 dB below

3. - E1C12

What types of communications may be transmitted to amateur stations in foreign countries?

Select	Answer
A	Messages intended for connection to users of the maritime satellite service
B	All of these choices are correct
C	Communications incidental to the purpose of the amateur service and remarks of a personal nature
D	Business-related messages for non-profit organizations

4. - E1D01

What is the definition of the term telemetry?

Select	Answer
A	Two-way single channel transmissions of data
B	Two-way radiotelephone transmissions in excess of 1000 feet
C	One-way transmission that initiates, modifies, or terminates the functions of a device at a distance
D	One-way transmission of measurements at a distance from the measuring instrument

5. - E1E08

To which of the following examinees may a VE not administer an examination?

Select	Answer
A	Employees of the VE
B	All of these choices are correct
C	Relatives of the VE as listed in the FCC rules
D	Friends of the VE

6. - E1F05

Amateur stations may not transmit in which of the following frequency segments if they are located in the contiguous 48 states and north of Line A?

Select	Answer
A	222 MHz - 223 MHz
B	440 MHz - 450 MHz
C	53 MHz - 54 MHz
D	420 MHz - 430 MHz

7. - E2A11

What type of antenna can be used to minimize the effects of spin modulation and Faraday rotation?

Select	Answer
A	An isotropic antenna
B	A linearly polarized antenna
C	A log-periodic dipole array
D	A circularly polarized antenna

8. - E2B01

How many times per second is a new frame transmitted in a fast-scan (NTSC) television system?

Select	Answer
A	60
B	120
C	90
D	30

9. - E2C02

Which of the following best describes the term self-spotting in regards to HF contest operating?

Select	Answer
A	An automatic method for rapidly zero beating or tuning to a station's frequency before calling that station
B	The generally prohibited practice of posting one's own call sign and frequency on a spotting network
C	A manual technique for rapidly zero beating or tuning to a station's frequency before calling that station
D	The acceptable practice of manually posting the call signs of stations on a spotting network

10. - E2D08

What type of packet frame is used to transmit APRS beacon data?

Select	Answer
A	Connect
B	Acknowledgement
C	Unnumbered Information
D	Disconnect

11. - E2E08

Which of the following HF digital modes can be used to transfer binary files?

Select	Answer
A	PACTOR
B	AMTOR
C	RTTY
D	Hellschreiber

12. - E3A15

What is an electromagnetic wave?

Select	Answer
A	A wave of alternating current, in the core of an electromagnet
B	A wave consisting of two electric fields at parallel right angles to each other
C	A wave consisting of two magnetic fields at right angles to each other
D	A wave consisting of an electric field and a magnetic field oscillating at right angles to each other

13. - E3B07

Which of the following could account for hearing an echo on the received signal of a distant station?

Select	Answer
A	High D layer absorption
B	Receipt of a signal by more than one path
C	Transmit frequency is higher than the MUF
D	Meteor scatter

14. - E3C15

What might a sudden rise in radio background noise indicate?

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

15. - E4A08

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

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

16. - E4B08

Which of the following is a characteristic of a good DC voltmeter?

Select	Answer
A	Low reluctance input
B	High reluctance input
C	High impedance input
D	Low impedance input

17. - E4C07

What does the MDS of a receiver represent?

Select	Answer
A	The maximum detectable spectrum
B	The meter display sensitivity
C	The minimum discernible signal
D	The multiplex distortion stability

18. - E4D08

What causes intermodulation in an electronic circuit?

Select	Answer
A	Positive feedback
B	Nonlinear circuits or devices
C	Too little gain
D	Lack of neutralization

19. - E4E16

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

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

20. - E5A16

What is the resonant frequency of a parallel RLC circuit if R is 33 ohms, L is 50 microhenrys and C is 10 picofarads?

Select	Answer
A	23.5 kHz
B	7.12 MHz
C	23.5 MHz
D	7.12 kHz

21. - E5B06

What is susceptance?

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

22. - E5C10

When using rectangular coordinates to graph the impedance of a circuit, what does the vertical axis represent?

Select	Answer
A	The sum of the reactive and resistive components
B	Resistive component
C	Reactive component
D	The difference between the resistive and reactive components

23. - E5D03

What is microstrip?

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

24. - E6A11

In Figure E6-2, what is the schematic symbol for a P-channel junction FET?

Select	Answer
A	2
B	3
C	1
D	6

25. - E6B03

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

Select	Answer
A	Junction
B	Zener
C	Tunnel
D	Point contact

26. - E6C09

What is a Programmable Logic Device (PLD)?

Select	Answer
A	Programmable equipment used for testing digital logic integrated circuits
B	An algorithm for simulating logic functions during circuit design
C	A programmable collection of logic gates and circuits in a single integrated circuit
D	A device to control industrial equipment

27. - E6D13

What is the primary cause of inductor self-resonance?

Select	Answer
A	Inter-turn capacitance
B	The skin effect
C	Non-linear core hysteresis
D	Inductive kickback

28. - E6E05

Which of the following noise figure values is typical of a low-noise UHF preamplifier?

Select	Answer
A	-10 dB
B	2 dB
C	-20 dBm
D	44 dBm

29. - E6F08

Why are optoisolators often used in conjunction with solid state circuits when switching 120VAC?

Select	Answer
A	Optoisolators eliminate the effects of reflected light in the control circuit
B	Optoisolators provide impedance matching between the control circuit and power circuit
C	Optoisolators provide a very high degree of electrical isolation between a control circuit and the circuit being switched
D	Optoisolators provide a low impedance link between a control circuit and a power circuit

30. - E7A07

What logical operation does a NAND gate perform?

Select	Answer
A	It produces logic "0" at its output only when all inputs are logic "1"
B	It produces logic "0" at its output only when all inputs are logic "0"
C	It produces logic "1" at its output only when all inputs are logic "1"
D	It produces logic "0" at its output if some but not all inputs are logic "1"

31. - E7B01

For what portion of a signal cycle does a Class AB amplifier operate?

Select	Answer
A	More than 180 degrees but less than 360 degrees
B	Exactly 180 degrees
C	Less than 180 degrees
D	The entire cycle

32. - E7C11

Which of the following is the common name for a filter network which is equivalent to two L-networks connected back-to-back with the two inductors in series and the capacitors in shunt at the input and output?

Select	Answer
A	Pi-L
B	Omega
C	Cascode
D	Pi

33. - E7D01

What is one characteristic of a linear electronic voltage regulator?

Select	Answer
A	It has a ramp voltage as its output
B	It eliminates the need for a pass transistor
C	The control element duty cycle is proportional to the line or load conditions
D	The conduction of a control element is varied to maintain a constant output voltage

34. - E7E11

Which type of detector is used for demodulating SSB signals?

Select	Answer
A	Product detector
B	Phase detector
C	Phase comparator
D	Discriminator

35. - E7F11

What sets the minimum detectable signal level for an SDR in the absence of atmospheric or thermal noise?

Select	Answer
A	Data storage transfer rate
B	Missing codes and jitter
C	Sample clock phase noise
D	Reference voltage level and sample width in bits

36. - E7G04

What is meant by the term op-amp input offset voltage?

Select	Answer
A	The output voltage of the op-amp minus its input voltage
B	The potential between the amplifier input terminals of the op-amp in an open loop condition
C	The differential input voltage needed to bring the open loop output voltage to zero
D	The difference between the output voltage of the op-amp and the input voltage required in the immediately following stage

37. - E7H07

How can an oscillator's microphonic responses be reduced?

Select	Answer
A	Using the oscillator only for CW and digital signals
B	Use of NP0 capacitors
C	Mechanically isolating the oscillator circuitry from its enclosure
D	Eliminating noise on the oscillator's power supply

38. - E8A09

How many levels can an analog-to-digital converter with 8 bit resolution encode?

Select	Answer
A	8 multiplied by the gain of the input amplifier
B	8
C	256
D	256 divided by the gain of the input amplifier

39. - E8B08

What describes Orthogonal Frequency Division Multiplexing?

Select	Answer
A	A bandwidth compression technique using Fourier transforms
B	A digital mode for narrow band, slow speed transmissions
C	A frequency modulation technique which uses non-harmonically related frequencies
D	A digital modulation technique using subcarriers at frequencies chosen to avoid intersymbol interference

40. - E8C08

How does ARQ accomplish error correction?

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

41. - E8D02

What spread spectrum communications technique uses a high speed binary bit stream to shift the phase of an RF carrier?

Select	Answer
A	Phase compandored spread spectrum
B	Binary phase-shift keying
C	Direct sequence
D	Frequency hopping

42. - E9A04

Which of the following factors may affect the feed point impedance of an antenna?

Select	Answer
A	Antenna height, conductor length/diameter ratio and location of nearby conductive objects
B	Sunspot activity and time of day
C	The settings of an antenna tuner at the transmitter
D	Transmission-line length

43. - E9B14

What type of information can be obtained by submitting the details of a proposed new antenna to a modeling program?

Select	Answer
A	All of these choices are correct
B	Polar plots of the far field elevation and azimuth patterns
C	SWR vs frequency charts
D	Antenna gain

44. - E9C08

What is a folded dipole antenna?

Select	Answer
A	A dipole consisting of one wavelength of wire forming a very thin loop
B	A type of ground-plane antenna
C	A dipole one-quarter wavelength long
D	A dipole configured to provide forward gain

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

46. - 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 omega match
B	The delta match
C	The stub match
D	The gamma match

47. - E9F09

What is the approximate physical length of a solid polyethylene dielectric coaxial transmission line that is electrically one-quarter wavelength long at 7.2 MHz?

Select	Answer
A	24 meters
B	10 meters
C	6.9 meters
D	50 meters

48. - E9G03

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

Select	Answer
A	Satellite azimuth and elevation bearings
B	Trigonometric functions
C	Beam headings and radiation patterns
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	One or more turns of wire wound in the shape of a large open coil
C	A small coil of wire tightly wound around a toroidal ferrite core
D	A large circularly polarized antenna

50. - E0A08

What does SAR measure?

Select	Answer
A	The rate at which RF energy is absorbed by the body
B	Signal Amplification Rating
C	Synthetic Aperture Ratio of the human body
D	The rate of RF energy reflected from stationary terrain

Figure E6-2