US Amateur Radio - Amateur Extra (Element 4, 2020-2024) Practice Test

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1. - E0A10

What toxic material may be present in some electronic components such as high voltage capacitors and transformers?

Select	Answer
A	Polytetrafluoroethylene
B	Polymorphic silicon
C	Polyethylene
D	Polychlorinated biphenyls

2. - E1A06

Where must the carrier frequency of a CW signal be set to comply with FCC rules for 60 meter operation?

Select	Answer
A	At the center frequency of the channel
B	At the lowest frequency of the channel
C	At the highest frequency of the channel
D	On any frequency where the signal's sidebands are within the channel

3. - E1B01

Which of the following constitutes a spurious emission?

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

4. - E1C09

What is the highest modulation index permitted at the highest modulation frequency for angle modulation below 29.0 MHz?

Select	Answer
A	0.5
B	1.0
C	3.0
D	2.0

5. - E1D06

What is the maximum permitted transmitter output power when operating a model craft by telecommand?

Select	Answer
A	5 watts
B	2 watts
C	1 watt
D	100 watts

6. - 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	Issue the examinee the new or upgrade license
D	Photocopy all examination documents and forward them to the FCC for processing

7. - E1F05

Amateur stations may not transmit in which of the following frequency segments if they are located in the contiguous 48 states and north of Line A?

Select	Answer
A	222 MHz - 223 MHz
B	420 MHz - 430 MHz
C	53 MHz - 54 MHz
D	440 MHz - 450 MHz

8. - E2A08

Why should effective radiated power to a satellite that 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 avoid interfering with terrestrial QSOs
D	To prevent the satellite from emitting out-of-band signals

9. - E2B11

What is the function of the Vertical Interval Signaling (VIS) code sent as part of an SSTV transmission?

Select	Answer
A	To lock the color burst oscillator in color SSTV images
B	To identify the call sign of the station transmitting
C	To identify the SSTV mode being used
D	To provide vertical synchronization

10. - E2C11

How should you generally identify your station when attempting to contact a DX station during a contest or in a pileup?

Select	Answer
A	Send only the last two letters of your call sign until you make contact
B	Send your full call sign once or twice
C	Send your full call sign and grid square
D	Send the call sign of the DX station three times, the words this is,then your call sign three times

11. - E2D06

Which of the following describes a method of establishing EME contacts?

Select	Answer
A	Storing and forwarding digital messages
B	High-speed CW identification to avoid fading
C	Judging optimum transmission times by monitoring beacons reflected from the moon
D	Time synchronous transmissions alternately from each station

12. - E2E08

Which of the following HF digital modes can be used to transfer binary files?

Select	Answer
A	AMTOR
B	PACTOR
C	RTTY
D	Hellschreiber

13. - E3A09

Which of the following frequency ranges is most suited for meteor scatter communications?

Select	Answer
A	1.8 MHz - 1.9 MHz
B	28 MHz - 148 MHz
C	10 MHz - 14 MHz
D	220 MHz - 450 MHz

14. - E3B03

What is the best time of day for transequatorial propagation?

Select	Answer
A	Noon
B	Morning
C	Late at night
D	Afternoon or early evening

15. - E3C04

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

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

16. - E4A01

Which of the following limits the highest frequency signal that can be accurately displayed on a digital oscilloscope?

Select	Answer
A	Sampling rate of the analog-to-digital converter
B	Amount of memory
C	Q of the circuit
D	All these choices are correct

17. - E4B01

Which of the following factors most affects the accuracy of a frequency counter?

Select	Answer
A	Decade divider accuracy
B	Time base accuracy
C	Temperature coefficient of the logic
D	Input attenuator accuracy

18. - E4C02

Which of the following receiver circuits can be effective in eliminating interference from strong out-of-band signals?

Select	Answer
A	A front-end filter or pre-selector
B	A properly adjusted product detector
C	A narrow IF filter
D	A notch filter

19. - E4D07

Which of the following reduces the likelihood of receiver desensitization?

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

20. - E4E10

What might be the cause of a loud roaring or buzzing AC line interference that comes and goes at intervals?

Select	Answer
A	A defective doorbell or doorbell transformer inside a nearby residence
B	All these choices are correct
C	A malfunctioning illuminated advertising display
D	Arcing contacts in a thermostatically controlled device

21. - E5A10

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

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

22. - E5B10

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

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

23. - E5C05

What is the name of the diagram used to show the phase relationship between impedances at a given frequency?

Select	Answer
A	Venn diagram
B	Near field diagram
C	Phasor diagram
D	Far field diagram

24. - E5D13

How many watts are consumed in a circuit consisting of a 100-ohm resistor in series with a 100-ohm inductive reactance drawing 1 ampere?

Select	Answer
A	141.4 watts
B	200 watts
C	100 watts
D	70.7 watts

25. - E6A07

Which of the following indicates that a silicon NPN junction transistor is biased on?

Select	Answer
A	Base-to-emitter voltage of approximately 6 to 7 volts
B	Base-to-emitter voltage of approximately 0.6 to 0.7 volts
C	Base-to-emitter resistance of approximately 0.6 to 0.7 ohms
D	Base-to-emitter resistance of approximately 6 to 7 ohms

26. - E6B06

Which of the following is a common use of a Schottky diode?

Select	Answer
A	As a variable capacitance in an automatic frequency control circuit
B	As a constant voltage reference in a power supply
C	As a rectifier in high current power supplies
D	As a VHF/UHF mixer or detector

27. - 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 an op-amp output that prevents signals from exceeding the power supply voltage
C	A resistor that ensures that an oscillator frequency does not drift
D	A resistor connected to the positive or negative supply line used to establish a voltage when an input or output is an open circuit

28. - E6D11

Which type of core material decreases inductance when inserted into a coil?

Select	Answer
A	Brass
B	Ferrite
C	Ceramic
D	Powdered iron

29. - 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	TO-220
C	Surface mount
D	Axial lead

30. - E6F05

Which describes an optical shaft encoder?

Select	Answer
A	A device that measures the strength of a beam of light using analog to digital conversion
B	A digital encryption device often used to encrypt spacecraft control signals
C	A device that 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

31. - 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

32. - E7B14

Why are switching amplifiers more efficient than linear amplifiers?

Select	Answer
A	Switching amplifiers use push-pull circuits
B	The power transistor is at saturation or cutoff most of the time
C	Switching amplifiers operate at higher voltages
D	Linear amplifiers have high gain resulting in higher harmonic content

33. - E7C05

Which filter type is described as having ripple in the passband and a sharp cutoff?

Select	Answer
A	A Chebyshev filter
B	A passive op-amp filter
C	A Butterworth filter
D	An active LC filter

34. - E7D13

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

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

35. - E7E05

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

Select	Answer
A	A heterodyne suppressor
B	A pre-emphasis network
C	A de-emphasis network
D	A heterodyne enhancer

36. - E7F07

What function is performed by a Fast Fourier Transform?

Select	Answer
A	Converting analog signals to digital form
B	Converting digital signals from the time domain to the frequency domain
C	Converting 8-bit data to 16-bit data
D	Converting digital signals to analog form

37. - E7G06

What is the gain-bandwidth of an operational amplifier?

Select	Answer
A	The frequency at which the open-loop gain of the amplifier equals one
B	The frequency at which the amplifier's offset voltage is zero
C	The gain of the amplifier at a filter's cutoff frequency
D	The maximum frequency for a filter circuit using that type of amplifier

38. - E7H11

What are the major spectral impurity components of direct digital synthesizers?

Select	Answer
A	Broadband noise
B	Nyquist limit noise
C	Spurious signals at discrete frequencies
D	Digital conversion noise

39. - E8A05

What of the following instruments would be the most accurate for measuring the RMS voltage of a complex waveform?

Select	Answer
A	A D'Arsonval meter
B	A true-RMS calculating meter
C	A grid dip meter
D	An absorption wave meter

40. - E8B01

What is the modulation index of an FM signal?

Select	Answer
A	The ratio of modulating signal amplitude to frequency deviation
B	The type of modulation used by the transmitter
C	The bandwidth of the transmitted signal divided by the modulating signal frequency
D	The ratio of frequency deviation to modulating signal frequency

41. - E8C10

How may data rate be increased without increasing bandwidth?

Select	Answer
A	Using forward error correction
B	It is impossible
C	Using a more efficient digital code
D	Increasing analog-to-digital conversion resolution

42. - E8D03

How does the spread spectrum technique of frequency hopping work?

Select	Answer
A	If interference is detected by the receiver it will signal the transmitter to wait until the frequency is clear
B	If interference is detected by the receiver it will signal the transmitter to change frequencies
C	A binary bit stream is used to shift the phase of an RF carrier very rapidly in a pseudorandom sequence
D	The frequency of the transmitted signal is changed very rapidly according to a pseudorandom sequence also used by the receiving station

43. - E9A10

Which of the following improves the efficiency of a ground-mounted quarter-wave vertical antenna?

Select	Answer
A	Isolating the coax shield from ground
B	Installing a radial system
C	All these choices are correct
D	Shortening the radiating element

44. - E9B02

In the antenna radiation pattern shown in Figure E9-1, what is the front-to-back ratio?

Select	Answer
A	24 dB
B	36 dB
C	14 dB
D	18 dB

45. - E9C03

What is the radiation pattern of two 1/4-wavelength vertical antennas spaced 1/2-wavelength apart and fed in phase?

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

46. - E9D12

Which of the following would provide the best RF ground for your station?

Select	Answer
A	An electrically short connection to 3 or 4 interconnected ground rods via a series RF choke
B	An electrically short connection to 3 or 4 interconnected ground rods driven into the Earth
C	A 50-ohm resistor connected to ground
D	An electrically short connection to a metal water pipe

47. - E9E10

Which of these choices is an effective way to match an antenna with a 100-ohm feed point impedance to a 50-ohm coaxial cable feed line?

Select	Answer
A	Insert a 1/2 wavelength piece of 300-ohm twinlead in series between the antenna terminals and the 50-ohm feed cable
B	Insert a 1/4-wavelength piece of 75-ohm coaxial cable transmission line in series between the antenna terminals and the 50-ohm feed cable
C	Connect a 1/2 wavelength shorted stub of 75-ohm cable in parallel with the 50-ohm cable where it attaches to the antenna
D	Connect a 1/4-wavelength open stub of 300-ohm twinlead in parallel with the coaxial feed line where it connects to the antenna

48. - E9F11

What impedance does a 1/8-wavelength transmission line present to a generator when the line is open at the far end?

Select	Answer
A	A capacitive reactance
B	Infinite
C	An inductive reactance
D	The same as the characteristic impedance of the line

49. - E9G04

What are the two families of circles and arcs that make up a Smith chart?

Select	Answer
A	Reactance and voltage
B	Resistance and voltage
C	Resistance and reactance
D	Voltage and impedance

50. - E9H03

What is Receiving Directivity Factor (RDF)?

Select	Answer
A	Forward gain compared to average gain over the entire hemisphere
B	Forward gain compared to the gain in the reverse direction
C	Relative directivity compared to a dipole
D	Relative directivity compared to isotropic

Figure E9-1