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	Yes, the displayed frequency is within the 80 meter CW band segment
B	No, one of the sidebands of the CW signal will be out of the band
C	No, U.S. stations are not permitted to use CW emissions below 3.525 MHz
D	Yes, the DX station initiated the contact

2. - E1B10

What frequencies are authorized to an amateur station operating under RACES rules?

Select	Answer
A	Military Auxiliary Radio System (MARS) channels
B	Specific local government channels
C	Specific segments in the amateur service MF, HF, VHF and UHF bands
D	All amateur service frequencies authorized to the control operator

3. - E1C04

What is meant by IARP?

Select	Answer
A	An indication of increased antenna reflected power
B	A forecast of intermittent aurora radio propagation
C	An international amateur radio permit that allows U.S. amateurs to operate in certain countries of the Americas
D	The internal amateur radio practices policy of the FCC

4. - E1D04

What is an Earth station in the amateur satellite service?

Select	Answer
A	An amateur station within 50 km of the Earth's surface intended for communications with amateur stations by means of objects in space
B	Any amateur station on the surface of the Earth
C	An amateur station that transmits telemetry consisting of measurement of upper atmosphere
D	An amateur station that is not able to communicate using amateur satellites

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 submit the application document to the coordinating VEC according to the coordinating VEC instructions
B	They must collect and send the documents to the NCVEC for grading
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. - 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 exhibit a gain of 0 dB or less over its full output range
D	It must be capable of external RF switching between its input and output networks

7. - E2A14

What technology is used to track, in real time, balloons carrying amateur radio transmitters?

Select	Answer
A	APRS
B	Radar
C	Bandwidth compressed LORAN
D	Doppler shift of beacon signals

8. - E2B14

What aspect of an amateur slow-scan television signal encodes the brightness of the picture?

Select	Answer
A	Tone frequency
B	Sync frequency
C	Sync amplitude
D	Tone amplitude

9. - E2C02

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

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

10. - E2D04

What is the purpose of digital store-and-forward functions on an Amateur Radio satellite?

Select	Answer
A	To delay download of telemetry between satellites
B	To upload operational software for the transponder
C	To relay messages between satellites
D	To store digital messages in the satellite for later download by other stations

11. - E2E09

Which of the following HF digital modes uses variable-length coding for bandwidth efficiency?

Select	Answer
A	PACTOR
B	RTTY
C	PSK31
D	MT63

12. - E3A14

From the contiguous 48 states, in which approximate direction should an antenna be pointed to take maximum advantage of aurora propagation?

Select	Answer
A	South
B	East
C	West
D	North

13. - E3B04

What is meant by the terms extraordinary and ordinary waves?

Select	Answer
A	Refracted rays and reflected waves
B	Independent waves created in the ionosphere that are elliptically polarized
C	Long path and short path waves
D	Extraordinary waves describe rare long skip propagation compared to ordinary waves which travel shorter distances

14. - E3C01

What does the term ray tracing describe in regard to radio communications?

Select	Answer
A	Evaluating high voltage sources for X-Rays
B	Determining the radiation pattern from an array of antennas
C	Modeling a radio wave's path through the ionosphere
D	The process in which an electronic display presents a pattern

15. - E4A12

Which of the following procedures is an important precaution to follow when connecting a spectrum analyzer to a transmitter output?

Select	Answer
A	All of these choices are correct
B	Attenuate the transmitter output going to the spectrum analyzer
C	Use high quality double shielded coaxial cables to reduce signal losses
D	Match the antenna to the load

16. - E4B04

If a frequency counter with a specified accuracy of +/- 0.1 ppm reads 146,520,000 Hz, what is the most the actual frequency being measured could differ from the reading?

Select	Answer
A	1.4652 kHz
B	0.1 MHz
C	1.4652 Hz
D	14.652 Hz

17. - E4C09

Which of the following choices is a good reason for selecting a high frequency for the design of the IF in a conventional HF or VHF communications receiver?

Select	Answer
A	Fewer components in the receiver
B	Reduced drift
C	Improved receiver noise figure
D	Easier for front-end circuitry to eliminate image responses

18. - E4D10

What does a third-order intercept level of 40 dBm mean with respect to receiver performance?

Select	Answer
A	A pair of 1 mW input signals will produce a third-order intermodulation product which is 40 dB stronger than the input signal
B	Signals less than 40 dBm will not generate audible third-order intermodulation products
C	A pair of 40 dBm signals will theoretically generate a third-order intermodulation product with the same level as the input signals
D	The receiver can tolerate signals up to 40 dB above the noise floor without producing third-order intermodulation products

19. - E4E01

Which of the following types of receiver noise can often be reduced by use of a receiver noise blanker?

Select	Answer
A	Broadband white noise
B	All of these choices are correct
C	Ignition noise
D	Heterodyne interference

20. - E5A04

What is the magnitude of the impedance of a circuit with a resistor, an inductor and a capacitor all in parallel, at resonance?

Select	Answer
A	Low, as compared to the circuit resistance
B	Approximately equal to capacitive reactance
C	Approximately equal to inductive reactance
D	Approximately equal to circuit resistance

21. - E5B03

What happens to the phase angle of a reactance when it is converted to a susceptance?

Select	Answer
A	It is shifted by 90 degrees
B	It is unchanged
C	The susceptance phase angle is the inverse of the reactance phase angle
D	The sign is reversed

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	Faraday grid
B	Elliptical coordinates
C	Polar coordinates
D	Maidenhead grid

23. - E5D03

What is microstrip?

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

24. - E6A15

Which semiconductor material contains excess holes in the outer shell of electrons?

Select	Answer
A	Bipolar-type
B	P-type
C	N-type
D	Superconductor-type

25. - E6B09

What is a common use for point contact diodes?

Select	Answer
A	As an RF detector
B	As a high voltage rectifier
C	As a constant current source
D	As a constant voltage source

26. - E6C09

What is a Programmable Logic Device (PLD)?

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

27. - E6D01

How many turns will be required to produce a 5-microhenry inductor using a powdered-iron toroidal core that has an inductance index (A L) value of 40 microhenrys/100 turns?

Select	Answer
A	141 turns
B	35 turns
C	79 turns
D	13 turns

28. - E6E03

Which of the following materials is likely to provide the highest frequency of operation when used in MMICs?

Select	Answer
A	Silicon
B	Silicon nitride
C	Silicon dioxide
D	Gallium nitride

29. - E6F09

What is the efficiency of a photovoltaic cell?

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

30. - E7A01

Which is a bi-stable circuit?

Select	Answer
A	An "OR" gate
B	An "AND" gate
C	A flip-flop
D	A clock

31. - E7B07

Which of the following is a likely result when a Class C amplifier is used to amplify a single-sideband phone signal?

Select	Answer
A	Reduced intermodulation products
B	Signal inversion
C	Increased overall intelligibility
D	Signal distortion and excessive bandwidth

32. - E7C04

How does an impedance-matching circuit transform a complex impedance to a resistive impedance?

Select	Answer
A	It cancels the reactive part of the impedance and changes the resistive part to a desired value
B	Network resistances are substituted for load resistances and reactances are matched to the resistances
C	It introduces transconductance to cancel the reactive part of impedance
D	It introduces negative resistance to cancel the resistive part of impedance

33. - E7D16

When several electrolytic filter capacitors are connected in series to increase the operating voltage of a power supply filter circuit, why should resistors be connected across each capacitor?

Select	Answer
A	To provide a safety bleeder to discharge the capacitors when the supply is off
B	To provide a minimum load current to reduce voltage excursions at light loads
C	To equalize, as much as possible, the voltage drop across each capacitor
D	All of these choices are correct

34. - E7E06

Why is de-emphasis commonly used in FM communications receivers?

Select	Answer
A	For higher efficiency
B	For compatibility with transmitters using phase modulation
C	To reduce impulse noise reception
D	To remove third-order distortion products

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	FIR filters delay all frequency components of the signal by the same amount
D	All of these choices are correct

36. - E7G08

How does the gain of an ideal operational amplifier vary with frequency?

Select	Answer
A	It does not vary with frequency
B	It increases linearly with increasing frequency
C	It decreases linearly with increasing frequency
D	It decreases logarithmically with increasing frequency

37. - E7H06

Which of the following oscillator circuits are commonly used in VFOs?

Select	Answer
A	Negative feedback and balanced feedback
B	Pierce and Zener
C	Armstrong and deForest
D	Colpitts and Hartley

38. - E8A01

What is the name of the process that shows that a square wave is made up of a sine wave plus all of its odd harmonics?

Select	Answer
A	Vector analysis
B	Fourier analysis
C	Numerical analysis
D	Differential analysis

39. - E8B09

What is meant by deviation ratio?

Select	Answer
A	The ratio of the maximum carrier frequency deviation to the highest audio modulating frequency
B	The ratio of the audio modulating frequency to the center carrier frequency
C	The ratio of the highest audio modulating frequency to the average audio modulating frequency
D	The ratio of the carrier center frequency to the audio modulating frequency

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. - E8D02

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

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

42. - E9A03

Why would one need to know the feed point impedance of an antenna?

Select	Answer
A	To match impedances in order to minimize standing wave ratio on the transmission line
B	To calculate the front-to-side ratio of the antenna
C	To calculate the front-to-back ratio of the antenna
D	To measure the near-field radiation density from a transmitting 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. - E9C06

What is the effect of a terminating resistor on a rhombic antenna?

Select	Answer
A	It reflects the standing waves on the antenna elements back to the transmitter
B	It changes the radiation pattern from bidirectional to unidirectional
C	It changes the radiation pattern from horizontal to vertical polarization
D	It decreases the ground loss

45. - E9D09

What is the function of a loading coil used as part of an HF mobile antenna?

Select	Answer
A	To cancel capacitive reactance
B	To increase the SWR bandwidth
C	To lower the Q
D	To lower the losses

46. - E9E08

Which of the following measurements is characteristic of a mismatched transmission line?

Select	Answer
A	An SWR greater than 1:1
B	A reflection coefficient greater than 1
C	An SWR less than 1:1
D	A dielectric constant greater than 1

47. - E9F03

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

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

48. - E9G10

What do the arcs on a Smith chart represent?

Select	Answer
A	Points with constant reactance
B	SWR
C	Points with constant resistance
D	Frequency

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

50. - E0A01

What is the primary function of an external earth connection or ground rod?

Select	Answer
A	Lightning protection
B	Reduce RFI to telephones and home entertainment systems
C	Reduce received noise
D	Reduce RF current flow between pieces of equipment

Figure E9-1