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

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1. - E1A03

With your transceiver displaying the carrier frequency of phone signals, you hear a station calling CQ on 14.349 MHz USB. Is it legal to return the call using upper sideband on the same frequency?

Select	Answer
A	No, the sideband will extend beyond the band edge
B	No, U.S. stations are not permitted to use phone emissions above 14.340 MHz
C	Yes, because the displayed frequency is within the 20 meter band
D	Yes, because you were not the station calling CQ

2. - E1B10

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

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

3. - E1C07

What is meant by local control?

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

4. - E1D05

What class of licensee is authorized to be the control operator of a space station?

Select	Answer
A	Any class with appropriate operator privileges
B	Only Amateur Extra Class
C	All except Technician Class
D	Only General, Advanced or Amateur Extra Class

5. - E1E07

What should a VE do if a candidate fails to comply with the examiner's instructions during an amateur operator license examination?

Select	Answer
A	Immediately terminate the candidate's examination
B	Warn the candidate that continued failure to comply will result in termination of the examination
C	Allow the candidate to complete the examination, but invalidate the results
D	Immediately terminate everyone's examination and close the session

6. - E1F10

What is the maximum permitted transmitter peak envelope power for an amateur station transmitting spread spectrum communications?

Select	Answer
A	1.5 W
B	10 W
C	1 W
D	1.5 kW

7. - E2A01

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

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

8. - E2B08

Which of the following is a common method of transmitting accompanying audio with amateur fast-scan television?

Select	Answer
A	Frequency-modulated sub-carrier
B	A separate VHF or UHF audio link
C	All of these choices are correct
D	Frequency modulation of the video carrier

9. - E2C06

During a VHF/UHF contest, in which band segment would you expect to find the highest level of activity?

Select	Answer
A	In the middle of the band, usually 25 kHz above the national calling frequency
B	At the top of each band, usually in a segment reserved for contests
C	In the middle of each band, usually on the national calling frequency
D	In the weak signal segment of the band, with most of the activity near the calling frequency

10. - E2D11

Which of the following data are used by the APRS network to communicate your location?

Select	Answer
A	Radio direction finding spectrum analysis
B	Time and frequency
C	Latitude and longitude
D	Polar coordinates

11. - E2E06

What is the most common data rate used for HF packet?

Select	Answer
A	110 baud
B	300 baud
C	48 baud
D	1200 baud

12. - E3A05

Tropospheric propagation of microwave signals often occurs along what weather related structure?

Select	Answer
A	Lightning discharges
B	Warm and cold fronts
C	Gray-line
D	Sprites and jets

13. - E3B11

At what time of day is Sporadic-E propagation most likely to occur?

Select	Answer
A	Around sunrise
B	Any time
C	Early evening
D	Around sunset

14. - E3C04

What does the value of Bz (B sub Z) represent?

Select	Answer
A	Geomagnetic field stability
B	Critical frequency for vertical transmissions
C	Duration of long-delayed echoes
D	Direction and strength of the interplanetary magnetic field

15. - E4A04

What determines the upper frequency limit for a computer soundcard-based oscilloscope program?

Select	Answer
A	Analog-to-digital conversion speed of the soundcard
B	All of these choices are correct
C	Q of the interface of the interface circuit
D	Amount of memory on the soundcard

16. - E4B09

What is indicated if the current reading on an RF ammeter placed in series with the antenna feed line of a transmitter increases as the transmitter is tuned to resonance?

Select	Answer
A	There is an impedance mismatch between the antenna and feed line
B	There is more power going into the antenna
C	The transmitter is not properly neutralized
D	There is possibly a short to ground in the feed line

17. - E4C04

How is the noise figure of a receiver defined?

Select	Answer
A	The ratio of the noise bandwidth in Hertz to the theoretical bandwidth of a resistive network
B	The ratio of atmospheric noise to phase noise
C	The ratio of thermal noise to atmospheric noise
D	The ratio in dB of the noise generated by the receiver to the theoretical minimum noise

18. - E4D02

Which of the following describes two problems caused by poor dynamic range in a communications receiver?

Select	Answer
A	Cross-modulation of the desired signal and insufficient audio power to operate the speaker
B	Cross-modulation of the desired signal and desensitization from strong adjacent signals
C	Oscillator instability requiring frequent retuning and loss of ability to recover the opposite sideband
D	Oscillator instability and severe audio distortion of all but the strongest received signals

19. - E4E05

How can noise from an electric motor be suppressed?

Select	Answer
A	By installing a bypass capacitor in series with the motor leads
B	By using a ground-fault current interrupter in the circuit used to power the motor
C	By installing a brute-force AC-line filter in series with the motor leads
D	By installing a high pass filter in series with the motor's power leads

20. - E5A14

What is the resonant frequency of a series RLC circuit if R is 22 ohms, L is 50 microhenrys and C is 40 picofarads?

Select	Answer
A	22.36 MHz
B	3.56 MHz
C	44.72 MHz
D	1.78 MHz

21. - E5B13

What letter is commonly used to represent susceptance?

Select	Answer
A	X
B	B
C	Y
D	G

22. - E5C11

What do the two numbers that are used to define a point on a graph using rectangular coordinates represent?

Select	Answer
A	The sine and cosine values
B	The tangent and cotangent values
C	The magnitude and phase of the point
D	The coordinate values along the horizontal and vertical axes

23. - E5D12

How many watts are consumed in a circuit having a power factor of 0.2 if the input is 100-VAC at 4 amperes?

Select	Answer
A	2000 watts
B	50 watts
C	400 watts
D	80 watts

24. - E6A03

Why does a PN-junction diode not conduct current when reverse biased?

Select	Answer
A	Only P-type semiconductor material can conduct current
B	Excess holes in P-type material combine with the electrons in N-type material, converting the entire diode into an insulator
C	Only N-type semiconductor material can conduct current
D	Holes in P-type material and electrons in the N-type material are separated by the applied voltage, widening the depletion region

25. - E6B01

What is the most useful characteristic of a Zener diode?

Select	Answer
A	A constant voltage drop under conditions of varying current
B	An internal capacitance that varies with the applied voltage
C	A constant current drop under conditions of varying voltage
D	A negative resistance region

26. - E6C07

What best describes a pull-up or pull-down resistor?

Select	Answer
A	A resistor in a keying circuit used to reduce key clicks
B	A resistor connected to the positive or negative supply line used to establish a voltage when an input or output is an open circuit
C	A resistor connected to an op-amp output that only functions when the logic output is false
D	A resistor that insures that an oscillator frequency does not drive lower over time

27. - E6D12

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

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

28. - E6E04

Which is the most common input and output impedance of circuits that use MMICs?

Select	Answer
A	10 ohms
B	450 ohms
C	50 ohms
D	300 ohms

29. - E6F11

What is the approximate open-circuit voltage produced by a fully-illuminated silicon photovoltaic cell?

Select	Answer
A	0.5 V
B	1.5 V
C	12 V
D	0.1 V

30. - E7A02

What is the function of a decade counter digital IC?

Select	Answer
A	It adds two decimal numbers together
B	It decodes a decimal number for display on a seven segment LED display
C	It produces ten output pulses for every input pulse
D	It produces one output pulse for every ten input pulses

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

32. - E7C14

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

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

33. - E7D13

What is the equation for calculating power dissipation by a series connected linear voltage regulator?

Select	Answer
A	Output voltage multiplied by output current
B	Input voltage divided by output current
C	Input voltage multiplied by input current
D	Voltage difference from input to output multiplied by output current

34. - E7E03

How does an analog phase modulator function?

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

35. - E7F02

What kind of digital signal processing audio filter is used to remove unwanted noise from a received SSB signal?

Select	Answer
A	An adaptive filter
B	A crystal-lattice filter
C	A phase-inverting filter
D	A Hilbert-transform filter

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	-2.3 volts
C	2.3 volts
D	-0.23 volts

37. - E7H03

How is positive feedback supplied in a Hartley oscillator?

Select	Answer
A	Through link coupling
B	Through a tapped coil
C	Through a capacitive divider
D	Through a neutralizing capacitor

38. - E8A05

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

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

39. - E8B11

What is digital time division multiplexing?

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

40. - E8C09

Which is the name of a digital code where each preceding or following character changes by only one bit?

Select	Answer
A	Excess 3 code
B	Extended Binary Coded Decimal Interchange Code
C	Binary Coded Decimal Code
D	Gray code

41. - E8D10

What are some of the differences between the Baudot digital code and ASCII?

Select	Answer
A	Baudot uses 5 data bits per character, ASCII uses 7 or 8; Baudot uses 2 characters as letters/figures shift codes, ASCII has no letters/figures shift code
B	Baudot uses 4 data bits per character, ASCII uses 7 or 8; Baudot uses 1 character as a letters/figures shift code, ASCII has no letters/figures code
C	Baudot uses 7 data bits per character, ASCII uses 8; Baudot has no letters/figures shift code, ASCII uses 2 letters/figures shift codes
D	Baudot uses 6 data bits per character, ASCII uses 7 or 8; Baudot has no letters/figures shift code, ASCII uses 2 letters/figures shift codes

42. - E9A08

What is meant by antenna bandwidth?

Select	Answer
A	The angle between the half-power radiation points
B	The angle formed between two imaginary lines drawn through the element ends
C	The frequency range over which an antenna satisfies a performance requirement
D	Antenna length divided by the number of elements

43. - E9B11

What is a disadvantage of decreasing the number of wire segments in an antenna model below the guideline of 10 segments per half-wavelength?

Select	Answer
A	Ground conductivity will not be accurately modeled
B	The antenna will become mechanically unstable
C	The computed feed point impedance may be incorrect
D	The resulting design will favor radiation of harmonic energy

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

45. - E9D03

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

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

46. - E9E12

What is the primary purpose of a phasing line when used with an antenna having multiple driven elements?

Select	Answer
A	It makes sure the antenna has a low-angle radiation pattern
B	It allows single-band antennas to operate on other bands
C	It ensures that each driven element operates in concert with the others to create the desired antenna pattern
D	It prevents reflected power from traveling back down the feed line and causing harmonic radiation from the transmitter

47. - E9F12

What impedance does a 1/4 wavelength transmission line present to a generator when the line is open at the far end?

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

48. - E9G08

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

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

49. - E9H06

What is the triangulation method of direction finding?

Select	Answer
A	Antenna headings from several different receiving locations are used to locate the signal source
B	A fixed receiving station plots three headings to the signal source
C	The geometric angles of sky waves from the source are used to determine its position
D	A fixed receiving station uses three different antennas to plot the location of the signal source

50. - E0A01

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

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

Figure E7-4