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

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1. - E1A14

What is the maximum bandwidth for a data emission on 60 meters?

Select	Answer
A	60 Hz
B	2.8 kHz
C	170 Hz
D	1.5 kHz

2. - E1B09

Which amateur stations may be operated under RACES rules?

Select	Answer
A	Only those club stations licensed to Amateur Extra class operators
B	Any FCC-licensed amateur station participating in the Military Auxiliary Radio System (MARS)
C	Any FCC-licensed amateur station except a Technician class
D	Any FCC-licensed amateur station certified by the responsible civil defense organization for the area served

3. - E1C10

What types of amateur stations may automatically retransmit the radio signals of other amateur stations?

Select	Answer
A	Only auxiliary, repeater or space stations
B	Only auxiliary, beacon or space stations
C	Only earth stations, repeater stations or model craft
D	Only beacon, repeater or space stations

4. - E1D06

Which of the following is a requirement of a space station?

Select	Answer
A	The space station must cease all transmissions after 5 years
B	The space station must be capable of changing its orbit whenever such a change is ordered by NASA
C	All of these choices are correct
D	The space station must be capable of terminating transmissions by telecommand when directed by the FCC

5. - E1E10

What must the administering VEs do after the administration of a successful examination for an amateur operator license?

Select	Answer
A	They must collect and send the documents to the NCVEC for grading
B	They must submit the application document to the coordinating VEC according to the coordinating VEC instructions
C	They must collect and send the documents to the FCC according to instructions
D	They must collect and submit the documents to the coordinating VEC for grading

6. - E1F06

Under what circumstances might the FCC issue a Special Temporary Authority (STA) to an amateur station?

Select	Answer
A	To provide for experimental amateur communications
B	To allow regular operation on Land Mobile channels
C	To provide additional spectrum for personal use
D	To provide temporary operation while awaiting normal licensing

7. - E2A02

What is the direction of a descending pass for an amateur satellite?

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

8. - E2B12

How are analog SSTV images typically transmitted on the HF bands?

Select	Answer
A	Varying tone frequencies representing the video are transmitted using single sideband
B	Video is converted to equivalent ASCII representation
C	Varying tone frequencies representing the video are transmitted using PSK
D	Video is converted to equivalent Baudot representation

9. - E2C07

What is the Cabrillo format?

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

10. - E2D09

Which of these digital modes has the fastest data throughput under clear communication conditions?

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

11. - E2E01

Which type of modulation is common for data emissions below 30 MHz?

Select	Answer
A	Spread spectrum
B	Pulse modulation
C	DTMF tones modulating an FM signal
D	FSK

12. - E3A04

What do Hepburn maps predict?

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

13. - E3B10

What is the cause of gray-line propagation?

Select	Answer
A	At mid-afternoon, the Sun heats the ionosphere decreasing radio wave refraction and the MUF
B	At midday, the Sun super heats the ionosphere causing increased refraction of radio waves
C	At twilight and sunrise, D-layer absorption is low while E-layer and F-layer propagation remains high
D	In darkness, solar absorption drops greatly while atmospheric ionization remains steady

14. - E3C03

Which of the following signal paths is most likely to experience high levels of absorption when the A index or K index is elevated?

Select	Answer
A	Transequatorial propagation
B	Polar paths
C	NVIS
D	Sporadic-E

15. - E4A05

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

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

16. - E4B11

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

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

17. - E4C14

What transmit frequency might generate an image response signal in a receiver tuned to 14.300 MHz and which uses a 455 kHz IF frequency?

Select	Answer
A	14.445 MHz
B	15.210 MHz
C	14.755 MHz
D	13.845 MHz

18. - E4D14

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

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

19. - E4E03

Which of the following signals might a receiver noise blanker be able to remove from desired signals?

Select	Answer
A	Signals which have a sharply peaked frequency distribution
B	Signals which appear across a wide bandwidth
C	Signals which appear at one IF but not another
D	Signals which are constant at all IF levels

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 MHz
B	23.5 kHz
C	7.12 MHz
D	7.12 kHz

21. - E5B10

What is the relationship between the current through an inductor and the voltage across an inductor?

Select	Answer
A	Current leads voltage by 90 degrees
B	Voltage leads current by 90 degrees
C	Voltage and current are 180 degrees out of phase
D	Voltage and current are in phase

22. - E5C04

Which of the following represents a capacitive reactance in polar coordinates?

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

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 resistance divided by the current
C	The amount of current flowing through the conductor
D	The diameter of the conductor

24. - E6A01

In what application is gallium arsenide used as a semiconductor material in preference to germanium or silicon?

Select	Answer
A	In microwave circuits
B	In high-power audio circuits
C	In high-current rectifier circuits
D	In very low frequency RF circuits

25. - E6B10

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

Select	Answer
A	1
B	7
C	5
D	6

26. - E6C11

In Figure E6-5, what is the schematic symbol for the NOT operation (inverter)?

Select	Answer
A	4
B	6
C	5
D	2

27. - E6D11

How many turns will be required to produce a 1-mH inductor using a core that has an inductance index (A L) value of 523 millihenrys/1000 turns?

Select	Answer
A	43 turns
B	229 turns
C	4 turns
D	2 turns

28. - E6E09

Which of the following component package types would be most suitable for use at frequencies above the HF range?

Select	Answer
A	Radial lead
B	Axial lead
C	TO-220
D	Surface mount

29. - E6F05

Which describes an optical shaft encoder?

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

30. - E7A10

What is a truth table?

Select	Answer
A	A diagram showing logic states when the digital device output is true
B	A table of logic symbols that indicate the high logic states of an op-amp
C	A list of inputs and corresponding outputs for a digital device
D	A table of logic symbols that indicate the logic states of an op-amp

31. - E7B08

How can an RF power amplifier be neutralized?

Select	Answer
A	By feeding an in-phase component of the output back to the input
B	By reducing the driving power
C	By feeding a 180-degree out-of-phase portion of the output back to the input
D	By increasing the driving power

32. - E7C07

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

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

33. - E7D10

What is the primary reason that a high-frequency switching type high voltage power supply can be both less expensive and lighter in weight than a conventional power supply?

Select	Answer
A	It uses a diode bridge rectifier for increased output
B	The inverter design does not require any output filtering
C	It uses a large power factor compensation capacitor to create free power from the unused portion of the AC cycle
D	The high frequency inverter design uses much smaller transformers and filter components for an equivalent power output

34. - E7E02

What is the function of a reactance modulator?

Select	Answer
A	To produce AM signals by using an electrically variable inductance or capacitance
B	To produce PM signals by using an electrically variable resistance
C	To produce AM signals by using an electrically variable resistance
D	To produce PM signals by using an electrically variable inductance or capacitance

35. - E7F15

Which of the following is an advantage of a Finite Impulse Response (FIR) filter vs an Infinite Impulse Response (IIR) digital filter?

Select	Answer
A	FIR filters can respond faster to impulses
B	FIR filters are easier to implement for a given set of passband rolloff requirements
C	All of these choices are correct
D	FIR filters delay all frequency components of the signal by the same amount

36. - E7G09

What will be the output voltage of the circuit shown in Figure E7-4 if R1 is 1000 ohms, RF is 10,000 ohms, and 0.23 volts DC is applied to the input?

Select	Answer
A	-0.23 volts
B	0.23 volts
C	-2.3 volts
D	2.3 volts

37. - E7H12

Which of the following must be done to insure that a crystal oscillator provides the frequency specified by the crystal manufacturer?

Select	Answer
A	Provide the crystal with a specified parallel capacitance
B	Bias the crystal at a specified current
C	Bias the crystal at a specified voltage
D	Provide the crystal with a specified parallel inductance

38. - E8A05

What would be the most accurate way of measuring the RMS voltage of a complex waveform?

Select	Answer
A	By using a grid dip meter
B	By measuring the voltage with a D'Arsonval meter
C	By measuring the heating effect in a known resistor
D	By using an absorption wave meter

39. - E8B01

What is the term for the ratio between the frequency deviation of an RF carrier wave and the modulating frequency of its corresponding FM-phone signal?

Select	Answer
A	Percentage of modulation
B	Modulation index
C	FM compressibility
D	Quieting index

40. - E8C11

What is the relationship between symbol rate and baud?

Select	Answer
A	They are the same
B	Baud is only used for RTTY
C	Baud is twice the symbol rate
D	Symbol rate is only used for packet-based modes

41. - E8D07

What is a common cause of overmodulation of AFSK signals?

Select	Answer
A	Ground loops
B	Excessive transmit audio levels
C	Excessive numbers of retries
D	Bit errors in the modem

42. - E9A15

What is the effective radiated power relative to a dipole of a repeater station with 150 watts transmitter power output, 2 dB feed line loss, 2.2 dB duplexer loss, and 7 dBd antenna gain?

Select	Answer
A	1977 watts
B	286 watts
C	420 watts
D	78.7 watts

43. - E9B04

What may occur when a directional antenna is operated at different frequencies within the band for which it was designed?

Select	Answer
A	The gain may change depending on frequency
B	Element spacing limits could be exceeded
C	The E-field and H-field patterns may reverse
D	Feed point impedance may become negative

44. - E9C05

What is an OCFD antenna?

Select	Answer
A	A remotely tunable dipole antenna using orthogonally controlled frequency diversity
B	A multiband dipole antenna using one-way circular polarization for frequency diversity
C	A dipole feed approximately 1/3 the way from one end with a 4:1 balun to provide multiband operation
D	An eight band dipole antenna using octophase filters

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 decreases
C	The front-to-back ratio increases
D	The SWR is reduced

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 delta match
B	The omega match
C	The gamma match
D	The stub match

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	Foam dielectric has lower safe operating voltage limits
C	All of these choices are correct
D	Foam dielectric has higher velocity factor

48. - E9G08

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

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

49. - E9H04

What is an advantage of using a shielded loop antenna for direction finding?

Select	Answer
A	It allows stations to communicate without giving away their position
B	It eliminates tracking errors caused by strong out-of-band signals
C	It automatically cancels ignition noise in mobile installations
D	It is electro statically balanced against ground, giving better nulls

50. - E0A03

Which of the following would be a practical way to estimate whether the RF fields produced by an amateur radio station are within permissible MPE limits?

Select	Answer
A	Use a calibrated antenna analyzer
B	All of the choices are correct
C	Use a hand calculator plus Smith-chart equations to calculate the fields
D	Use an antenna modeling program to calculate field strength at accessible locations

Figure E6-3

Figure E6-5

Figure E7-4