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

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1. - E1A09

What is the first action you should take if your digital message forwarding station inadvertently forwards a communication that violates FCC rules?

Select	Answer
A	Discontinue forwarding all messages
B	Discontinue forwarding the communication as soon as you become aware of it
C	Notify the nearest FCC Field Engineer's office
D	Notify the originating station that the communication does not comply with FCC rules

2. - E1B03

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

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

3. - E1C07

What is meant by local control?

Select	Answer
A	Controlling a repeater using a portable handheld transceiver
B	Direct manipulation of the transmitter by a control operator
C	Automatically manipulating local station controls
D	Controlling a station through a local auxiliary link

4. - E1D01

What is the definition of the term telemetry?

Select	Answer
A	One-way transmission that initiates, modifies, or terminates the functions of a device at a distance
B	Two-way single channel transmissions of data
C	Two-way radiotelephone transmissions in excess of 1000 feet
D	One-way transmission of measurements at a distance from the measuring instrument

5. - E1E01

What is the minimum number of qualified VEs required to administer an Element 4 amateur operator license examination?

Select	Answer
A	4
B	3
C	5
D	2

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 additional spectrum for personal use
C	To provide for experimental amateur communications
D	To provide temporary operation while awaiting normal licensing

7. - E2A08

Why should effective radiated power to a satellite which uses a linear transponder be limited?

Select	Answer
A	To avoid reducing the downlink power to all other users
B	To prevent creating errors in the satellite telemetry
C	To prevent the satellite from emitting out-of-band signals
D	To avoid interfering with terrestrial QSOs

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

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

10. - E2D04

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

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

11. - E2E10

Which of these digital modes has the narrowest bandwidth?

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

12. - E3A10

Which type of atmospheric structure can create a path for microwave propagation?

Select	Answer
A	Dust devil
B	The jet stream
C	Wind shear
D	Temperature inversion

13. - E3B08

What type of HF propagation is probably occurring if radio signals travel along the terminator between daylight and darkness?

Select	Answer
A	Sporadic-E
B	Gray-line
C	Transequatorial
D	Long-path

14. - E3C11

What does VOACAP software model?

Select	Answer
A	AC current and impedance
B	AC voltage and impedance
C	VHF radio propagation
D	HF propagation

15. - E4A06

What is the effect of aliasing in a digital or computer-based oscilloscope?

Select	Answer
A	All signals will have a DC offset
B	False triggering occurs
C	False signals are displayed
D	Calibration of the vertical scale is no longer valid

16. - E4B12

What is the significance of voltmeter sensitivity expressed in ohms per volt?

Select	Answer
A	When used as an ohmmeter, the reading in ohms divided by the ohms per volt rating will determine the voltage applied to the circuit
B	When used as a galvanometer, the reading in volts multiplied by the ohms per volt rating will determine the power drawn by the device under test
C	When used as an ammeter, the full scale reading in amps divided by ohms per volt rating will determine the size of shunt needed
D	The full scale reading of the voltmeter multiplied by its ohms per volt rating will indicate the input impedance of the voltmeter

17. - E4C08

An SDR receiver is overloaded when input signals exceed what level?

Select	Answer
A	The reference voltage of the analog-to-digital converter
B	One-half the maximum sampling buffer size
C	One-half the maximum sample rate
D	The maximum count value of the analog-to-digital converter

18. - E4D10

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

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

19. - E4E10

What is a common characteristic of interference caused by a touch controlled electrical device?

Select	Answer
A	The interfering signal sounds like AC hum on an AM receiver or a carrier modulated by 60 Hz hum on a SSB or CW receiver
B	The interfering signal can be several kHz in width and usually repeats at regular intervals across a HF band
C	The interfering signal may drift slowly across the HF spectrum
D	All of these choices are correct

20. - E5A09

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

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

21. - E5B04

What is the time constant of a circuit having two 220 microfarad capacitors and two 1 megohm resistors, all in parallel?

Select	Answer
A	220 seconds
B	110 seconds
C	440 seconds
D	55 seconds

22. - E5C13

What coordinate system is often used to display the resistive, inductive, and/or capacitive reactance components of impedance?

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

23. - E5D14

What is reactive power?

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

24. - E6A15

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

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

25. - E6B13

What type of bias is required for an LED to emit light?

Select	Answer
A	Forward bias
B	Inductive bias
C	Reverse bias
D	Zero bias

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 IC input can be damaged
C	The feedback loop becomes unstable
D	The comparator enters latch-up

27. - E6D17

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

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

28. - E6E12

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

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

29. - E6F02

What happens to the conductivity of a photoconductive material when light shines on it?

Select	Answer
A	It decreases
B	It stays the same
C	It becomes unstable
D	It increases

30. - E7A03

Which of the following can divide the frequency of a pulse train by 2?

Select	Answer
A	An OR gate
B	A flip-flop
C	A multiplexer
D	An XOR gate

31. - E7B08

How can an RF power amplifier be neutralized?

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

32. - E7C09

What is a Jones filter as used as part of an HF receiver IF stage?

Select	Answer
A	A variable bandwidth crystal lattice filter
B	An automatic notch filter
C	A filter that removes impulse noise E7C10 (B) Which of the following filters would be the best choice for use in a 2 meter repeater duplexer? A. A crystal filter B. A cavity filter C. A DSP filter D. An L-C filter
D	A special filter that emphasizes image responses

33. - E7D06

What is the purpose of Q1 in the circuit shown in Figure E7-3?

Select	Answer
A	It provides D1 with current
B	It provides negative feedback to improve regulation
C	It provides a constant load for the voltage source
D	It increases the current-handling capability of the regulator

34. - E7E05

What circuit is added to an FM transmitter to boost the higher audio frequencies?

Select	Answer
A	A heterodyne suppressor
B	An audio prescaler
C	A pre-emphasis network
D	A de-emphasis network

35. - E7F03

What type of digital signal processing filter is used to generate an SSB signal?

Select	Answer
A	An elliptical filter
B	A Hilbert-transform filter
C	A notch filter
D	An adaptive filter

36. - E7G03

What is the typical input impedance of an integrated circuit op-amp?

Select	Answer
A	1000 ohms
B	Very low
C	Very high
D	100 ohms

37. - E7H14

What is a phase-locked loop circuit?

Select	Answer
A	An electronic servo loop consisting of a phase detector, a low-pass filter, a voltage-controlled oscillator, and a stable reference oscillator
B	An electronic circuit consisting of a precision push-pull amplifier with a differential input
C	An electronic servo loop consisting of a ratio detector, reactance modulator, and voltage-controlled oscillator
D	An electronic circuit also known as a monostable multivibrator

38. - E8A10

What is the purpose of a low pass filter used in conjunction with a digital-to-analog converter?

Select	Answer
A	Improve accuracy by removing out of sequence codes from the input
B	All of these choices are correct
C	Remove harmonics from the output caused by the discrete analog levels generated
D	Lower the input bandwidth to increase the effective resolution

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 carrier center frequency to the audio modulating frequency
D	The ratio of the highest audio modulating frequency to the average 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	Extended Binary Coded Decimal Interchange Code
C	Excess 3 code
D	Gray code

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 receiver is always equipped with a digital blanker
C	The high power used by a spread spectrum transmitter keeps its signal from being easily overpowered
D	Signals not using the spread spectrum algorithm are suppressed in the receiver

42. - E9A06

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

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

43. - E9B12

What is the far field of an antenna?

Select	Answer
A	The region where the shape of the antenna pattern is independent of distance
B	The region where radiated field strengths are obstructed by objects of reflection
C	The region where radiated power dissipates over a specified time period
D	The region of the ionosphere where radiated power is not refracted

44. - E9C15

How does the radiation pattern of a horizontally polarized 3-element beam antenna vary with its height above ground?

Select	Answer
A	The horizontal beam width decreases with height
B	The horizontal beam width increases with height
C	The main lobe takeoff angle decreases with increasing height
D	The main lobe takeoff angle increases with increasing height

45. - E9D03

Where should a high Q loading coil be placed to minimize losses in a shortened vertical antenna?

Select	Answer
A	Near the center of the vertical radiator
B	As close to the transmitter as possible
C	At a voltage node
D	As low as possible on the vertical radiator

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

47. - E9F14

What impedance does a 1/2 wavelength transmission line present to a generator when the line is shorted at the far end?

Select	Answer
A	The same as the output impedance of the generator
B	Very low impedance
C	The same as the characteristic impedance of the line
D	Very high impedance

48. - E9G11

How are the wavelength scales on a Smith chart calibrated?

Select	Answer
A	In fractions of antenna electrical frequency
B	In fractions of transmission line electrical frequency
C	In fractions of transmission line electrical wavelength
D	In fractions of antenna electrical wavelength

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

50. - E0A09

Which insulating material commonly used as a thermal conductor for some types of electronic devices is extremely toxic if broken or crushed and the particles are accidentally inhaled?

Select	Answer
A	Uranium Hexafluoride
B	Mica
C	Beryllium Oxide
D	Zinc oxide

Figure E7-3