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	No, U.S. stations are not permitted to use CW emissions below 3.525 MHz
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	Yes, the DX station initiated the contact

2. - E1B03

Within what distance must an amateur station protect an FCC monitoring facility from harmful interference?

Select	Answer
A	30 miles
B	3 miles
C	1 mile
D	10 miles

3. - E1C12

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

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

4. - E1D10

Which amateur stations are eligible to be telecommand stations?

Select	Answer
A	Any amateur station designated by NASA
B	Any amateur station so designated by the ITU
C	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
D	All of these choices are correct

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. - E1F11

Which of the following best describes one of the standards that must be met by an external RF power amplifier if it is to qualify for a grant of FCC certification?

Select	Answer
A	It must produce full legal output when driven by not more than 5 watts of mean RF input power
B	It must satisfy the FCC's spurious emission standards when operated at the lesser of 1500 watts or its full output power
C	It must be capable of external RF switching between its input and output networks
D	It must exhibit a gain of 0 dB or less over its full output range

7. - E2A13

What type of satellite appears to stay in one position in the sky?

Select	Answer
A	Geomagnetic
B	Geostationary
C	LEO
D	HEO

8. - E2B16

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

Select	Answer
A	DRM
B	NTSC
C	Scottie
D	PAL

9. - E2C04

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

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

10. - E2D12

How does JT65 improve EME communications?

Select	Answer
A	It controls the receiver to track Doppler shift
B	It can decode signals many dB below the noise floor using FEC
C	It supplies signals to guide the antenna to track the Moon
D	All of these choices are correct

11. - E2E11

What is the difference between direct FSK and audio FSK?

Select	Answer
A	Audio FSK has a superior frequency response
B	Direct FSK applies the data signal to the transmitter VFO
C	Direct FSK uses a DC-coupled data connection
D	Audio FSK can be performed anywhere in the transmit chain

12. - E3A13

Which emission mode is best for aurora propagation?

Select	Answer
A	CW
B	RTTY
C	FM
D	SSB

13. - E3B02

What is the approximate maximum range for signals using transequatorial propagation?

Select	Answer
A	7500 miles
B	2500 miles
C	1000 miles
D	5000 miles

14. - E3C07

Which of the following descriptors indicates the greatest solar flare intensity?

Select	Answer
A	Class M
B	Class X
C	Class B
D	Class A

15. - E4A09

When using a computer's soundcard input to digitize signals, what is the highest frequency signal that can be digitized without aliasing?

Select	Answer
A	One-tenth the sample rate
B	The same as the sample rate
C	It depends on how the data is stored internally
D	One-half the sample rate

16. - E4B13

Which S parameter is equivalent to forward gain?

Select	Answer
A	S12
B	S22
C	S21
D	S11

17. - E4C12

What is an undesirable effect of using too wide a filter bandwidth in the IF section of a receiver?

Select	Answer
A	Output-offset overshoot
B	Thermal-noise distortion
C	Filter ringing
D	Undesired signals may be heard

18. - E4D05

What transmitter frequencies would cause an intermodulation-product signal in a receiver tuned to 146.70 MHz when a nearby station transmits on 146.52 MHz?

Select	Answer
A	146.10 MHz and 147.30 MHz
B	146.88 MHz and 146.34 MHz
C	173.35 MHz and 139.40 MHz
D	146.34 MHz and 146.61 MHz

19. - E4E15

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

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

20. - E5A10

How is the Q of an RLC series resonant circuit calculated?

Select	Answer
A	Resistance divided by the reactance of either the inductance or capacitance
B	Reactance of the inductance times the reactance of the capacitance
C	Reactance of either the inductance or capacitance times the resistance
D	Reactance of either the inductance or capacitance divided by the resistance

21. - E5B08

What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 100 ohms, R is 100 ohms, and XL is 75 ohms?

Select	Answer
A	14 degrees with the voltage leading the current
B	76 degrees with the voltage lagging the current
C	76 degrees with the voltage leading the current
D	14 degrees with the voltage lagging the current

22. - E5C16

Which point on Figure E5-2 best represents the impedance of a series circuit consisting of a 300 ohm resistor and a 19 picofarad capacitor at 21.200 MHz?

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

23. - E5D11

What is the power factor of an R-L circuit having a 60 degree phase angle between the voltage and the current?

Select	Answer
A	1.73
B	0.866
C	0.5
D	1.414

24. - E6A05

What is the alpha of a bipolar junction transistor?

Select	Answer
A	The change of collector current with respect to emitter current
B	The change of collector current with respect to gate current
C	The change of base current with respect to collector current
D	The change of collector current with respect to base current

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

26. - E6C12

What is BiCMOS logic?

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

27. - E6D15

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

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

28. - E6E11

What is a characteristic of DIP packaging used for integrated circuits?

Select	Answer
A	A total of two rows of connecting pins placed on opposite sides of the package (Dual In-line Package)
B	Low leakage doubly insulated package
C	Package mounts in a direct inverted position
D	Two chips in each package (Dual In Package)

29. - E6F03

What is the most common configuration of an optoisolator or optocoupler?

Select	Answer
A	A lens and a photomultiplier
B	A frequency modulated helium-neon laser
C	An amplitude modulated helium-neon laser
D	An LED and a phototransistor

30. - E7A04

How many flip-flops are required to divide a signal frequency by 4?

Select	Answer
A	8
B	4
C	2
D	1

31. - E7B01

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

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

32. - E7C07

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

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

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. - 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	A beat frequency is generated
D	Automatic limiting occurs

35. - E7F11

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

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

36. - E7G12

What is an integrated circuit operational amplifier?

Select	Answer
A	A RF amplifier used in the UHF and microwave regions
B	A high-gain, direct-coupled differential amplifier with very high input impedance and very low output impedance
C	A digital audio amplifier whose characteristics are determined by components external to the amplifier
D	An amplifier used to increase the average output of frequency modulated amateur signals to the legal limit

37. - E7H10

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

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

38. - E8A12

What is an advantage of using digital signals instead of analog signals to convey the same information?

Select	Answer
A	Digital signals can be regenerated multiple times without error
B	Less complex circuitry is required for digital signal generation and detection
C	All of these choices are correct
D	Digital signals always occupy a narrower bandwidth

39. - E8B07

Orthogonal Frequency Division Multiplexing is a technique used for which type of amateur communication?

Select	Answer
A	Extremely low-power contacts
B	High speed digital modes
C	EME
D	OFDM signals are not allowed on amateur bands

40. - E8C09

Which is the name of a digital code where each preceding or following character changes by only one bit?

Select	Answer
A	Binary Coded Decimal Code
B	Excess 3 code
C	Gray code
D	Extended Binary Coded Decimal Interchange Code

41. - E8D05

What is the most common method of reducing key clicks?

Select	Answer
A	Increase keying waveform rise and fall times
B	High-pass filters at the transmitter output
C	Reduce keying waveform rise and fall times
D	Low-pass filters at the transmitter output

42. - E9A06

How does the beamwidth of an antenna vary as the gain is increased?

Select	Answer
A	It decreases
B	It increases geometrically
C	It increases arithmetically
D	It is essentially unaffected

43. - E9B03

In the antenna radiation pattern shown in Figure E9-1, what is the front-to-side ratio?

Select	Answer
A	12 dB
B	24 dB
C	18 dB
D	14 dB

44. - E9C09

What is a G5RV antenna?

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

45. - E9D08

What happens as the Q of an antenna increases?

Select	Answer
A	Gain is reduced
B	SWR bandwidth increases
C	More common-mode current is present on the feed line
D	SWR bandwidth decreases

46. - E9E04

What is the purpose of the series capacitor in a gamma-type antenna matching network?

Select	Answer
A	To provide DC isolation between the feed line and the antenna
B	To provide a rejection notch that prevents the radiation of harmonics
C	To cancel the inductive reactance of the matching network
D	To transform the antenna impedance to a higher value

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	6.9 meters
B	10 meters
C	50 meters
D	24 meters

48. - E9G08

What is the process of normalization with regard to a Smith chart?

Select	Answer
A	Reassigning prime center with regard to the reactance axis
B	Reassigning impedance values with regard to the prime center
C	Reassigning reactance values with regard to the resistance axis
D	Reassigning resistance values with regard to the reactance axis

49. - E9H09

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

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

50. - E0A06

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

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

Figure E5-2

Figure E9-1