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

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1. - E1A07

Which amateur band requires transmission on specific channels rather than on a range of frequencies?

Select	Answer
A	60 meter band
B	17 meter band
C	30 meter band
D	12 meter band

2. - E1B07

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

Select	Answer
A	1.0
B	2.0
C	0.5
D	3.0

3. - E1C11

Which of the following operating arrangements allows an FCC-licensed U.S. citizen to operate in many European countries, and alien amateurs from many European countries to operate in the U.S.?

Select	Answer
A	IARP agreement
B	ITU reciprocal license
C	All of these choices are correct
D	CEPT agreement

4. - E1D07

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

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

5. - E1E04

Which of the following best describes the Volunteer Examiner accreditation process?

Select	Answer
A	The prospective VE obtains accreditation from the FCC
B	The amateur operator applying must pass a VE examination administered by the FCC Enforcement Bureau
C	The procedure by which a VEC confirms that the VE applicant meets FCC requirements to serve as an examiner
D	Each General, Advanced and Amateur Extra Class operator is automatically accredited as a VE when the license is granted

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	53 MHz - 54 MHz
C	420 MHz - 430 MHz
D	440 MHz - 450 MHz

7. - E2A01

What is the direction of an ascending pass for an amateur satellite?

Select	Answer
A	From east to west
B	From south to north
C	From north to south
D	From west to east

8. - E2B04

What is blanking in a video signal?

Select	Answer
A	Turning off the scanning beam while it is traveling from right to left or from bottom to top
B	Turning off the scanning beam at the conclusion of a transmission
C	Transmitting a black and white test pattern
D	Synchronization of the horizontal and vertical sync pulses

9. - E2C07

What is the Cabrillo format?

Select	Answer
A	A method of exchanging information during a contest QSO
B	The rules of order for meetings between contest sponsors
C	The most common set of contest rules
D	A standard for submission of electronic contest logs

10. - E2D12

How does JT65 improve EME communications?

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

11. - E2E10

Which of these digital modes has the narrowest bandwidth?

Select	Answer
A	170 Hz shift, 45 baud RTTY
B	MFSK16
C	PSK31
D	300-baud packet

12. - E3A12

What is the cause of auroral activity?

Select	Answer
A	Meteor showers concentrated in the extreme northern and southern latitudes
B	A low sunspot level combined with tropospheric ducting
C	The interaction in the E layer of charged particles from the Sun with the Earth's magnetic field
D	The interaction in the F2 layer between the solar wind and the Van Allen belt

13. - E3B06

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

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

14. - E3C02

What is indicated by a rising A or K index?

Select	Answer
A	Increasing disruption of the geomagnetic field
B	An increase in the critical frequency
C	Decreasing disruption of the geomagnetic field
D	Higher levels of solar UV radiation

15. - E4A07

Which of the following is an advantage of using an antenna analyzer compared to an SWR bridge to measure antenna SWR?

Select	Answer
A	Antenna analyzers display a time-varying representation of the modulation envelope
B	All of these choices are correct
C	Antenna analyzers do not need an external RF source
D	Antenna analyzers automatically tune your antenna for resonance

16. - E4B17

What three test loads are used to calibrate a standard RF vector network analyzer?

Select	Answer
A	Short circuit, open circuit, and 50 ohms
B	50 ohms through 1/8 wavelength, 1/4 wavelength, and 1/2 wavelength of coaxial cable
C	Short circuit, open circuit, and resonant circuit
D	50 ohms, 75 ohms, and 90 ohms

17. - E4C11

Which of the following is a desirable amount of selectivity for an amateur SSB phone receiver?

Select	Answer
A	1 kHz
B	2.4 kHz
C	4.2 kHz
D	4.8 kHz

18. - E4D07

Which describes the most significant effect of an off-frequency signal when it is causing cross-modulation interference to a desired signal?

Select	Answer
A	A large increase in background noise
B	A reduction in apparent signal strength
C	The off-frequency unwanted signal is heard in addition to the desired signal
D	The desired signal can no longer be heard

19. - E4E15

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

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

20. - E5A06

What is the magnitude of the circulating current within the components of a parallel LC circuit at resonance?

Select	Answer
A	It equals 2 multiplied by Pi, multiplied by frequency, multiplied by inductance
B	It is at a maximum
C	It equals 1 divided by the quantity 2 times Pi, multiplied by the square root of inductance L multiplied by capacitance C
D	It is at a minimum

21. - E5B12

What is admittance?

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

22. - E5C08

What coordinate system is often used to display the phase angle of a circuit containing resistance, inductive and/or capacitive reactance?

Select	Answer
A	Polar coordinates
B	Elliptical coordinates
C	Faraday grid
D	Maidenhead grid

23. - E5D17

How many watts are consumed in a circuit having a power factor of 0.6 if the input is 200VAC at 5 amperes?

Select	Answer
A	1600 watts
B	200 watts
C	1000 watts
D	600 watts

24. - E6A02

Which of the following semiconductor materials contains excess free electrons?

Select	Answer
A	P-type
B	N-type
C	Insulated gate
D	Bipolar

25. - E6B06

Which of the following is a common use of a hot-carrier diode?

Select	Answer
A	As a VHF/UHF mixer or detector
B	As balanced mixers in FM generation
C	As a variable capacitance in an automatic frequency control circuit
D	As a constant voltage reference in a power supply

26. - E6C02

What happens when the level of a comparator's input signal crosses the threshold?

Select	Answer
A	The comparator changes its output state
B	The feedback loop becomes unstable
C	The comparator enters latch-up
D	The IC input can be damaged

27. - E6D17

Why should core saturation of a conventional impedance matching transformer be avoided?

Select	Answer
A	RF susceptance would increase
B	Magnetic flux would increase with frequency
C	Temporary changes of the core permeability could result
D	Harmonics and distortion could result

28. - E6E01

Which of the following is true of a charge-coupled device (CCD)?

Select	Answer
A	It samples an analog signal and passes it in stages from the input to the output
B	It is a CMOS analog-to-digital converter
C	Its phase shift changes rapidly with frequency
D	It is used in a battery charger circuit

29. - E6F09

What is the efficiency of a photovoltaic cell?

Select	Answer
A	The open-circuit voltage divided by the short-circuit current under full illumination
B	The output RF power divided by the input DC power
C	The relative fraction of light that is converted to current
D	The effective payback period

30. - E7A05

Which of the following is a circuit that continuously alternates between two states without an external clock?

Select	Answer
A	Monostable multivibrator
B	Astable multivibrator
C	J-K flip-flop
D	T flip-flop

31. - E7B09

Which of the following describes how the loading and tuning capacitors are to be adjusted when tuning a vacuum tube RF power amplifier that employs a Pi-network output circuit?

Select	Answer
A	The tuning capacitor is set to maximum capacitance and the loading capacitor is adjusted for minimum plate permissible current
B	The tuning capacitor is adjusted for minimum plate current, and the loading capacitor is adjusted for maximum permissible plate current
C	The loading capacitor is set to maximum capacitance and the tuning capacitor is adjusted for minimum allowable plate current
D	The loading capacitor is adjusted to minimum plate current while alternately adjusting the tuning capacitor for maximum allowable plate current

32. - E7C15

What is a crystal lattice filter?

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

33. - E7D04

Which of the following types of linear voltage regulator usually make the most efficient use of the primary power source?

Select	Answer
A	A shunt current source
B	A series regulator
C	A series current source
D	A shunt regulator

34. - E7E07

What is meant by the term baseband in radio communications?

Select	Answer
A	The lowest frequency band that the transmitter or receiver covers
B	The unmodulated bandwidth of the transmitted signal
C	The basic oscillator frequency in an FM transmitter that is multiplied to increase the deviation and carrier frequency
D	The frequency components present in the modulating signal

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	Reference voltage level and sample width in bits
D	Sample clock phase noise

36. - E7G02

What is the effect of ringing in a filter?

Select	Answer
A	A reduction in high frequency response
B	Partial cancellation of the signal over a range of frequencies
C	Undesired oscillations added to the desired signal
D	An echo caused by a long time delay

37. - E7H15

Which of these functions can be performed by a phase-locked loop?

Select	Answer
A	Photovoltaic conversion, optical coupling
B	Wide-band AF and RF power amplification
C	Comparison of two digital input signals, digital pulse counter
D	Frequency synthesis, FM demodulation

38. - E8A04

What is "dither" with respect to analog to digital converters?

Select	Answer
A	An error caused by irregular quantization step size
B	A method of decimation by randomly skipping samples
C	An abnormal condition where the converter cannot settle on a value to represent the signal
D	A small amount of noise added to the input signal to allow more precise representation of a signal over time

39. - E8B11

What is digital time division multiplexing?

Select	Answer
A	Two or more data streams are assigned to discrete sub-carriers on an FM transmitter
B	Two or more signals are arranged to share discrete time slots of a data transmission
C	Two or more signals are quadrature modulated to increase bandwidth efficiency
D	Two or more data streams share the same channel by transmitting time of transmission as the sub-carrier

40. - E8C02

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

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

41. - E8D08

What parameter might indicate that excessively high input levels are causing distortion in an AFSK signal?

Select	Answer
A	Signal to noise ratio
B	Baud rate
C	Intermodulation Distortion (IMD)
D	Repeat Request Rate (RRR)

42. - E9A02

What antenna has no gain in any direction?

Select	Answer
A	Isotropic antenna
B	Half-wave dipole
C	Yagi
D	Quarter-wave vertical

43. - E9B03

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

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

44. - E9C08

What is a folded dipole antenna?

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

45. - E9D12

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

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

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 1/2 wavelength piece of 300 ohm twin-lead in series between the antenna terminals and the 50 ohm feed cable
B	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
C	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
D	Connect 1/2 wavelength shorted stub of 75 ohm cable in parallel with the 50 ohm cable where it attaches to the antenna

47. - E9F16

Which of the following is a significant difference between foam dielectric coaxial cable and solid dielectric cable, assuming all other parameters are the same?

Select	Answer
A	Foam dielectric has lower loss per unit of length
B	All of these choices are correct
C	Foam dielectric has higher velocity factor
D	Foam dielectric has lower safe operating voltage limits

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. - E9H01

When constructing a Beverage antenna, which of the following factors should be included in the design to achieve good performance at the desired frequency?

Select	Answer
A	Its overall length must not exceed 1/4 wavelength
B	It must be mounted more than 1 wavelength above ground
C	It should be configured as a four-sided loop
D	It should be one or more wavelengths long

50. - E0A08

What does SAR measure?

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

Figure E9-1