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

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1. - E1A04

With your transceiver displaying the carrier frequency of phone signals, you hear a DX station calling CQ on 3.601 MHz LSB. Is it legal to return the call using lower sideband on the same frequency?

Select	Answer
A	No, U.S. stations are not permitted to use phone emissions below 3.610 MHz
B	Yes, because the DX station initiated the contact
C	No, the sideband will extend beyond the edge of the phone band segment
D	Yes, because the displayed frequency is within the 75 meter phone band segment

2. - E1B01

Which of the following constitutes a spurious emission?

Select	Answer
A	An amateur station transmission made at random without the proper call sign identification
B	Any transmitted signal that unintentionally interferes with another licensed radio station
C	An emission outside its necessary bandwidth that can be reduced or eliminated without affecting the information transmitted
D	A signal transmitted to prevent its detection by any station other than the intended recipient

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. - E1D08

Which VHF amateur service bands have frequencies available for space stations?

Select	Answer
A	2 meters and 1.25 meters
B	6 meters, 2 meters, and 1.25 meters
C	2 meters
D	6 meters and 2 meters

5. - E1E11

What must the VE team do if an examinee scores a passing grade on all examination elements needed for an upgrade or new license?

Select	Answer
A	Three VEs must certify that the examinee is qualified for the license grant and that they have complied with the administering VE requirements
B	All these choices are correct
C	Photocopy all examination documents and forward them to the FCC for processing
D	Issue the examinee the new or upgrade license

6. - E1F07

When may an amateur station send a message to a business?

Select	Answer
A	When the total money involved does not exceed $25
B	When transmitting international third-party communications
C	When neither the amateur nor his or her employer has a pecuniary interest in the communications
D	When the control operator is employed by the FCC or another government agency

7. - E2A02

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

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

8. - E2B04

What is blanking in a video signal?

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

9. - E2C10

Why might a DX station state that they are listening on another frequency?

Select	Answer
A	To separate the calling stations from the DX station
B	Because the DX station may be transmitting on a frequency that is prohibited to some responding stations
C	All of these choices are correct
D	To improve operating efficiency by reducing interference

10. - E2D03

Which of the following digital modes is especially useful for EME communications?

Select	Answer
A	JT65
B	Olivia
C	FSK441
D	PACTOR III

11. - E2E09

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

Select	Answer
A	PSK31
B	PACTOR
C	MT63
D	RTTY

12. - E3A15

What is an electromagnetic wave?

Select	Answer
A	A wave consisting of an electric field and a magnetic field oscillating at right angles to each other
B	A wave consisting of two magnetic fields at right angles to each other
C	A wave of alternating current, in the core of an electromagnet
D	A wave consisting of two electric fields at parallel right angles to each other

13. - E3B12

What is the primary characteristic of chordal hop propagation?

Select	Answer
A	Successive ionospheric reflections without an intermediate reflection from the ground
B	Propagation away from the great circle bearing between stations
C	Propagation across the geomagnetic equator
D	Signals reflected back toward the transmitting station

14. - E3C11

What does VOACAP software model?

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

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

16. - E4B11

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

Select	Answer
A	Connect the antenna feed line directly to the analyzer's connector
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	Loosely couple the analyzer near the antenna base

17. - E4C05

What does a value of -174 dBm/Hz represent with regard to the noise floor of a receiver?

Select	Answer
A	The noise figure of a 1 Hz bandwidth receiver
B	The theoretical noise at the input of a perfect receiver at room temperature
C	The galactic noise contribution to minimum detectable signal
D	The minimum detectable signal as a function of receive frequency

18. - E4D12

What is the term for the reduction in receiver sensitivity caused by a strong signal near the received frequency?

Select	Answer
A	Desensitization
B	Cross-modulation interference
C	Quieting
D	Squelch gain rollback

19. - E4E04

How can conducted and radiated noise caused by an automobile alternator be suppressed?

Select	Answer
A	By installing a noise suppression resistor and a blocking capacitor in both leads
B	By installing filter capacitors in series with the DC power lead and a blocking capacitor in the field lead
C	By installing a high-pass filter in series with the radio's power lead and a low-pass filter in parallel with the field lead
D	By connecting the radio's power leads directly to the battery and by installing coaxial capacitors in line with the alternator leads

20. - E5A02

What is resonance in an electrical circuit?

Select	Answer
A	The frequency at which the reactive impedance equals the resistive impedance
B	The highest frequency that will pass current
C	The lowest frequency that will pass current
D	The frequency at which the capacitive reactance equals the inductive reactance

21. - E5B09

What is the relationship between the current through a capacitor and the voltage across a capacitor?

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

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 3
B	Point 8
C	Point 7
D	Point 1

23. - E5D10

How can the true power be determined in an AC circuit where the voltage and current are out of phase?

Select	Answer
A	By dividing the reactive power by the power factor
B	By multiplying the reactive power times the power factor
C	By multiplying the apparent power times the power factor
D	By dividing the apparent power by the power factor

24. - E6A13

What do the initials CMOS stand for?

Select	Answer
A	Complementary Mica-Oxide Silicon
B	Complementary Metal-Oxide Semiconductor
C	Common Mode Organic Silicon
D	Common Mode Oscillating System

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	Controlled reverse avalanche voltage
B	Much higher reverse voltage breakdown
C	Less forward voltage drop
D	Enhanced carrier retention time

26. - E6C05

What is an advantage of CMOS logic devices over TTL devices?

Select	Answer
A	Lower distortion
B	Differential output capability
C	Immune to damage from static discharge
D	Lower power consumption

27. - E6D12

What is the definition of saturation in a ferrite core inductor?

Select	Answer
A	The ability of the inductor's core to store magnetic energy has been exceeded
B	The inductor's voltage rating is exceeded causing a flashover
C	Adjacent inductors become over-coupled
D	The inductor windings are over coupled

28. - E6E08

How is voltage from a power supply normally furnished to the most common type of monolithic microwave integrated circuit (MMIC)?

Select	Answer
A	Directly to the bias voltage (VCC IN) lead
B	Through a resistor and/or RF choke connected to the amplifier output lead
C	MMICs require no operating bias
D	Through a capacitor and RF choke connected to the amplifier input lead

29. - E6F09

What is the efficiency of a photovoltaic cell?

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

30. - E7A05

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

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

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

32. - E7C14

Which mode is most affected by non-linear phase response in a receiver IF filter?

Select	Answer
A	Single-Sideband voice
B	Digital
C	Video
D	Meteor scatter

33. - E7D14

What is one purpose of a "bleeder" resistor in a conventional unregulated power supply?

Select	Answer
A	To boost the amount of output current
B	To cut down on waste heat generated by the power supply
C	To balance the low-voltage filament windings
D	To improve output voltage regulation

34. - E7E03

How does an analog phase modulator function?

Select	Answer
A	By varying the tuning of an amplifier tank circuit to produce PM signals
B	By varying the tuning of a microphone preamplifier to produce PM signals
C	By varying the tuning of a microphone preamplifier to produce AM signals
D	By varying the tuning of an amplifier tank circuit to produce AM signals

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

36. - E7G01

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

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

37. - E7H08

Which of the following components can be used to reduce thermal drift in crystal oscillators?

Select	Answer
A	Toroidal inductors
B	NP0 capacitors
C	Non-inductive resistors
D	Wirewound resistors

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	Fourier analysis
B	Vector analysis
C	Differential analysis
D	Numerical analysis

39. - E8B08

What describes Orthogonal Frequency Division Multiplexing?

Select	Answer
A	A digital modulation technique using subcarriers at frequencies chosen to avoid intersymbol interference
B	A digital mode for narrow band, slow speed transmissions
C	A frequency modulation technique which uses non-harmonically related frequencies
D	A bandwidth compression technique using Fourier transforms

40. - E8C08

How does ARQ accomplish error correction?

Select	Answer
A	If errors are detected, a retransmission is requested
B	Special polynomial codes provide automatic correction
C	If errors are detected, redundant data is substituted
D	Special binary codes provide automatic correction

41. - E8D01

Why are received spread spectrum signals resistant to interference?

Select	Answer
A	Signals not using the spread spectrum algorithm are suppressed in the receiver
B	The high power used by a spread spectrum transmitter keeps its signal from being easily overpowered
C	The receiver is always equipped with a digital blanker
D	If interference is detected by the receiver it will signal the transmitter to change frequencies

42. - E9A09

How is antenna efficiency calculated?

Select	Answer
A	(total resistance / radiation resistance) x 100 per cent
B	(effective radiated power / transmitter output) x 100 percent
C	(radiation resistance / transmission resistance) x 100 per cent
D	(radiation resistance / total resistance) x 100 per cent

43. - E9B13

What does the abbreviation NEC stand for when applied to antenna modeling programs?

Select	Answer
A	National Electrical Code
B	Numerical Electromagnetic Code
C	Numeric Electrical Computation
D	Next Element Comparison

44. - E9C02

What is the radiation pattern of two 1/4 wavelength vertical antennas spaced 1/4 wavelength apart and fed 90 degrees out of phase?

Select	Answer
A	Cardioid
B	A figure-8 end-fire along the axis of the array
C	Omni-directional
D	A figure-8 broadside to the axis of the array

45. - E9D02

How can linearly polarized Yagi antennas be used to produce circular polarization?

Select	Answer
A	Arrange two Yagis perpendicular to each other with the driven elements at the same point on the boom fed 90 degrees out of phase
B	Stack two Yagis fed in phase to form an array with the respective elements in parallel planes
C	Stack two Yagis fed 90 degrees out of phase to form an array with the respective elements in parallel planes
D	Arrange two Yagis collinear to each other with the driven elements fed 180 degrees out of phase

46. - E9E02

What is the name of an antenna matching system that matches an unbalanced feed line to an antenna by feeding the driven element both at the center of the element and at a fraction of a wavelength to one side of center?

Select	Answer
A	The stub match
B	The delta match
C	The epsilon match
D	The gamma match

47. - E9F02

Which of the following determines the velocity factor of a transmission line?

Select	Answer
A	Dielectric materials used in the line
B	The line length
C	The center conductor resistivity
D	The termination impedance

48. - E9G06

On the Smith chart shown in Figure E9-3, what is the name for the large outer circle on which the reactance arcs terminate?

Select	Answer
A	Polar axis
B	Prime axis
C	Reactance axis
D	Impedance axis

49. - E9H05

What is the main drawback of a wire-loop antenna for direction finding?

Select	Answer
A	It receives equally well in all directions
B	It is practical for use only on VHF bands
C	It is non-rotatable
D	It has a bidirectional pattern

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	Zinc oxide
B	Mica
C	Beryllium Oxide
D	Uranium Hexafluoride

Figure E5-2

Figure E9-3