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

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

3. - E1C05

When may an automatically controlled station originate third party communications?

Select	Answer
A	When approved by the National Telecommunication and Information Administration
B	Only when transmitting RTTY or data emissions
C	Never
D	When agreed upon by the sending or receiving station

4. - E1D07

Which amateur service HF bands have frequencies authorized for space stations?

Select	Answer
A	Only the 40 m, 20 m, 17 m, 15 m, 12 m and 10 m bands
B	Only the 40 m, 20 m, 17 m, 15 m and 10 m bands
C	Only the 40 m, 30 m, 20 m, 15 m, 12 m and 10 m bands
D	All HF bands

5. - E1E09

What may be the penalty for a VE who fraudulently administers or certifies an examination?

Select	Answer
A	A sentence of up to one year in prison
B	All of these choices are correct
C	Revocation of the VE's amateur station license grant and the suspension of the VE's amateur operator license grant
D	A fine of up to $1000 per occurrence

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. - E2A11

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

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

8. - E2B05

Which of the following is an advantage of using vestigial sideband for standard fast- scan TV transmissions?

Select	Answer
A	Vestigial sideband provides high frequency emphasis to sharpen the picture
B	Vestigial sideband reduces bandwidth while allowing for simple video detector circuitry
C	The vestigial sideband carries the audio information
D	The vestigial sideband contains chroma information

9. - E2C12

What might help to restore contact when DX signals become too weak to copy across an entire HF band a few hours after sunset?

Select	Answer
A	Wait 24 hours before attempting another communication on the band
B	Wait 90 minutes or so for the signal degradation to pass
C	Switch to a higher frequency HF band
D	Switch to a lower frequency HF band

10. - E2D11

Which of the following data are used by the APRS network to communicate your location?

Select	Answer
A	Time and frequency
B	Polar coordinates
C	Radio direction finding spectrum analysis
D	Latitude and longitude

11. - E2E13

Which of the following is a possible reason that attempts to initiate contact with a digital station on a clear frequency are unsuccessful?

Select	Answer
A	All of these choices are correct
B	Your transmit frequency is incorrect
C	Another station you are unable to hear is using the frequency
D	The protocol version you are using is not the supported by the digital station

12. - E3A16

Which of the following best describes electromagnetic waves traveling in free space?

Select	Answer
A	The waves are reflected by the ionosphere and return to their source
B	The energy propagates through a medium with a high refractive index
C	Electric and magnetic fields become aligned as they travel
D	Changing electric and magnetic fields propagate the energy

13. - E3B05

Which amateur bands typically support long-path propagation?

Select	Answer
A	160 meters to 10 meters
B	6 meters to 2 meters
C	160 meters to 40 meters
D	30 meters to 10 meters

14. - E3C06

By how much does the VHF/UHF radio horizon distance exceed the geometric horizon?

Select	Answer
A	By approximately 15 percent of the distance
B	By approximately twice the distance
C	By approximately four times the distance
D	By approximately 50 percent of the distance

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. - E4B11

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

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

17. - E4C17

Which of the following has the largest effect on an SDR receiver's linearity?

Select	Answer
A	CPU register width in bits
B	Analog-to-digital converter sample width in bits
C	Anti-aliasing input filter bandwidth
D	RAM speed used for data storage

18. - E4D11

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

Select	Answer
A	The third-order product of two signals which are in the band of interest is also likely to be within the band
B	Third-order intermodulation produces three products for every input signal within the band of interest
C	Third-order products are an indication of poor image rejection
D	The third-order intercept is much higher than other orders

19. - E4E09

What undesirable effect can occur when using an IF noise blanker?

Select	Answer
A	Received audio in the speech range might have an echo effect
B	FM signals can no longer be demodulated
C	Nearby signals may appear to be excessively wide even if they meet emission standards
D	The audio frequency bandwidth of the received signal might be compressed

20. - E5A14

What is the resonant frequency of a series RLC circuit if R is 22 ohms, L is 50 microhenrys and C is 40 picofarads?

Select	Answer
A	1.78 MHz
B	44.72 MHz
C	3.56 MHz
D	22.36 MHz

21. - E5B12

What is admittance?

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

22. - E5C12

If you plot the impedance of a circuit using the rectangular coordinate system and find the impedance point falls on the right side of the graph on the horizontal axis, what do you know about the circuit?

Select	Answer
A	It contains resistance and capacitive reactance
B	It contains resistance and inductive reactance
C	It is equivalent to a pure resistance
D	It has to be a direct current circuit

23. - E5D14

What is reactive power?

Select	Answer
A	Power consumed in wire resistance in an inductor
B	Power consumed in circuit Q
C	Power lost because of capacitor leakage
D	Wattless, nonproductive power

24. - E6A04

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

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

25. - E6B10

In Figure E6-3, what is the schematic symbol for a light-emitting diode?

Select	Answer
A	1
B	7
C	6
D	5

26. - E6C13

Which of the following is an advantage of BiCMOS logic?

Select	Answer
A	Its simplicity results in much less expensive devices than standard CMOS
B	It has the high input impedance of CMOS and the low output impedance of bipolar transistors
C	It is totally immune to electrostatic damage
D	All of these choices are correct

27. - E6D06

What core material property determines the inductance of a toroidal inductor?

Select	Answer
A	Permeability
B	Resistance
C	Reactivity
D	Thermal impedance

28. - E6E12

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

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

29. - E6F05

Which describes an optical shaft encoder?

Select	Answer
A	A device which measures the strength of a beam of light using analog to digital conversion
B	A device which detects rotation of a control by interrupting a light source with a patterned wheel
C	A device for generating RTTY signals by means of a rotating light source
D	A digital encryption device often used to encrypt spacecraft control signals

30. - E7A06

What is a characteristic of a monostable multivibrator?

Select	Answer
A	It switches momentarily to the opposite binary state and then returns to its original state after a set time
B	It maintains a constant output voltage, regardless of variations in the input voltage
C	It produces a continuous square wave oscillating between 1 and 0
D	It stores one bit of data in either a 0 or 1 state

31. - E7B11

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

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

32. - E7C15

What is a crystal lattice filter?

Select	Answer
A	A filter with narrow bandwidth and steep skirts made using quartz crystals
B	A power supply filter made with interlaced quartz crystals
C	An audio filter made with four quartz crystals that resonate at 1kHz intervals
D	A filter with wide bandwidth and shallow skirts made using quartz crystals

33. - E7D12

What is the drop-out voltage of an analog voltage regulator?

Select	Answer
A	Minimum input-to-output voltage required to maintain regulation
B	Maximum amount that the output voltage drops when the input voltage is varied over its specified range
C	Minimum input voltage for rated power dissipation
D	Maximum amount that the output voltage may decrease at rated load

34. - E7E03

How does an analog phase modulator function?

Select	Answer
A	By varying the tuning of an amplifier tank circuit to produce PM signals
B	By varying the tuning of a microphone preamplifier to produce AM signals
C	By varying the tuning of a microphone preamplifier to produce PM signals
D	By varying the tuning of an amplifier tank circuit to produce AM signals

35. - E7F07

What function can a Fast Fourier Transform perform?

Select	Answer
A	Converting analog signals to digital form
B	Converting digital signals to analog form
C	Converting digital signals from the time domain to the frequency domain
D	Converting 8-bit data to 16 bit data

36. - E7G11

What absolute voltage gain can be expected from the circuit in Figure E7-4 when R1 is 3300 ohms and RF is 47 kilohms?

Select	Answer
A	14
B	0.07
C	7
D	28

37. - E7H02

Which describes a microphonic?

Select	Answer
A	Excess loading of the microphone by an oscillator
B	An IC used for amplifying microphone signals
C	Distortion caused by RF pickup on the microphone cable
D	Changes in oscillator frequency due to mechanical vibration

38. - E8A11

What type of information can be conveyed using digital waveforms?

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

39. - E8B03

What is the modulation index of an FM-phone signal having a maximum frequency deviation of 3000 Hz either side of the carrier frequency when the modulating frequency is 1000 Hz?

Select	Answer
A	3
B	1000
C	0.3
D	3000

40. - E8C07

What is the necessary bandwidth of a 4800-Hz frequency shift, 9600-baud ASCII FM transmission?

Select	Answer
A	4.8 kHz
B	15.36 kHz
C	9.6 kHz
D	5.76 kHz

41. - E8D01

Why are received spread spectrum signals resistant to interference?

Select	Answer
A	If interference is detected by the receiver it will signal the transmitter to change frequencies
B	The high power used by a spread spectrum transmitter keeps its signal from being easily overpowered
C	The receiver is always equipped with a digital blanker
D	Signals not using the spread spectrum algorithm are suppressed in the receiver

42. - E9A14

What is meant by the radiation resistance of an antenna?

Select	Answer
A	The combined losses of the antenna elements and feed line
B	The value of a resistance that would dissipate the same amount of power as that radiated from an antenna
C	The resistance in the atmosphere that an antenna must overcome to be able to radiate a signal
D	The specific impedance of the antenna

43. - E9B01

In the antenna radiation pattern shown in Figure E9-1, what is the 3 dB beam-width?

Select	Answer
A	30 degrees
B	75 degrees
C	25 degrees
D	50 degrees

44. - E9C07

What is the approximate feed point impedance at the center of a two-wire folded dipole antenna?

Select	Answer
A	72 ohms
B	450 ohms
C	50 ohms
D	300 ohms

45. - E9D13

What usually occurs if a Yagi antenna is designed solely for maximum forward gain?

Select	Answer
A	The frequency response is widened over the whole frequency band
B	The front-to-back ratio increases
C	The front-to-back ratio decreases
D	The SWR is reduced

46. - E9E05

How must the driven element in a 3-element Yagi be tuned to use a hairpin matching system?

Select	Answer
A	The driven element reactance must be inductive
B	The driven element resonance must be lower than the operating frequency
C	The driven element reactance must be capacitive
D	The driven element radiation resistance must be higher than the characteristic impedance of the transmission line

47. - E9F03

Why is the physical length of a coaxial cable transmission line shorter than its electrical length?

Select	Answer
A	The characteristic impedance is higher in a parallel feed line
B	Electrical signals move more slowly in a coaxial cable than in air
C	Skin effect is less pronounced in the coaxial cable
D	The surge impedance is higher in a parallel feed line

48. - E9G06

On the Smith chart shown in Figure E9-3, what is the name for the large outer circle on which the reactance arcs terminate?

Select	Answer
A	Polar axis
B	Impedance axis
C	Reactance axis
D	Prime axis

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. - E0A10

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

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

Figure E6-3

Figure E7-1

Figure E7-4

Figure E9-1

Figure E9-3