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

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1. - 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

2. - E1A11

Which of the following describes authorization or licensing required when operating an amateur station aboard a U.S.-registered vessel in international waters?

Select	Answer
A	An unrestricted Radiotelephone Operator Permit
B	Only General Class or higher amateur licenses
C	Any amateur license with an FCC Marine or Aircraft endorsement
D	Any FCC-issued amateur license

3. - E1B01

Which of the following constitutes a spurious emission?

Select	Answer
A	An amateur station transmission made without the proper call sign identification
B	An emission outside the signal's necessary bandwidth that can be reduced or eliminated without affecting the information transmitted
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. - E1C06

Which of the following is required in order to operate in accordance with CEPT rules in foreign countries where permitted?

Select	Answer
A	The U.S. embassy must approve of your operation
B	You must bring a copy of FCC Public Notice DA 16-1048
C	You must identify in the official language of the country in which you are operating
D	You must append "/CEPT" to your call sign

5. - E1D11

Which amateur stations are eligible to operate as Earth stations?

Select	Answer
A	Any amateur station whose licensee has filed a pre-space notification with the FCC's International Bureau
B	Any amateur station, subject to the privileges of the class of operator license held by the control operator
C	Only those of General, Advanced or Amateur Extra Class operators
D	Only those of Amateur Extra Class operators

6. - E1E08

To which of the following examinees may a VE not administer an examination?

Select	Answer
A	Employees of the VE
B	Relatives of the VE as listed in the FCC rules
C	All these choices are correct
D	Friends of the VE

7. - E1F10

Who may be the control operator of an auxiliary station?

Select	Answer
A	Only General, Advanced or Amateur Extra Class operators
B	Only Technician, General, Advanced or Amateur Extra Class operators
C	Only Amateur Extra Class operators
D	Any licensed amateur operator

8. - E2A07

Which of the following types of signals can be relayed through a linear transponder?

Select	Answer
A	SSB and SSTV
B	PSK and packet
C	FM and CW
D	All these choices are correct

9. - E2B01

How many times per second is a new frame transmitted in a fast-scan (NTSC) television system?

Select	Answer
A	120
B	60
C	90
D	30

10. - E2C05

What is the function of a DX QSL Manager?

Select	Answer
A	To handle the receiving and sending of confirmation cards for a DX station
B	To allocate frequencies for DXpeditions
C	To relay calls to and from a DX station
D	To run a net to allow many stations to contact a rare DX station

11. - E2D11

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

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

12. - E2E03

How is the timing of FT4 contacts organized?

Select	Answer
A	By exchanging ACK/NAK packets
B	Alternating transmissions at 7.5 second intervals
C	It depends on the lunar phase
D	Stations take turns on alternate days

13. - E3A13

Which of these emission modes is best for auroral propagation?

Select	Answer
A	FM
B	CW
C	SSB
D	RTTY

14. - E3B03

What is the best time of day for transequatorial propagation?

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

15. - E3C15

What might be indicated by a sudden rise in radio background noise across a large portion of the HF spectrum?

Select	Answer
A	A solar flare has occurred
B	Long-path propagation is likely
C	A temperature inversion has occurred
D	Increased transequatorial propagation is likely

16. - E4A01

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

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

17. - E4B03

Which S parameter is equivalent to forward gain?

Select	Answer
A	S21
B	S11
C	S12
D	S22

18. - E4C07

What does the MDS of a receiver represent?

Select	Answer
A	The multiplex distortion stability
B	The meter display sensitivity
C	The maximum detectable spectrum
D	The minimum discernible signal

19. - E4D08

What causes intermodulation in an electronic circuit?

Select	Answer
A	Too little gain
B	Positive feedback
C	Nonlinear circuits or devices
D	Lack of neutralization

20. - E4E05

How can radio frequency interference from an AC motor be suppressed?

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

21. - E5A04

What is the magnitude of the impedance of a parallel RLC circuit at resonance?

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

22. - E5B03

How is impedance in polar form converted to an equivalent admittance?

Select	Answer
A	Take the reciprocal of the angle and change the sign of the magnitude
B	Take the square root of the magnitude and add 180 degrees to the angle
C	Take the reciprocal of the magnitude and change the sign of the angle
D	Square the magnitude and subtract 90 degrees from the angle

23. - 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	Maidenhead grid
B	Faraday grid
C	Polar coordinates
D	Elliptical coordinates

24. - E5D03

What is microstrip?

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

25. - E6A03

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

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

26. - E6B11

What is used to control the attenuation of RF signals by a PIN diode?

Select	Answer
A	Reverse voltage larger than the RF signal
B	Capacitance of an RF coupling capacitor
C	Forward DC bias current
D	A sub-harmonic pump signal

27. - E6C02

What happens when the level of a comparator's input signal crosses the threshold?

Select	Answer
A	The IC input can be damaged
B	The comparator changes its output state
C	The comparator enters latch-up
D	The feedback loop becomes unstable

28. - E6D06

What core material property determines the inductance of an inductor?

Select	Answer
A	Resistance
B	Permeability
C	Thermal impedance
D	Reactivity

29. - E6E05

Which of the following noise figure values is typical of a low-noise UHF preamplifier?

Select	Answer
A	44 dBm
B	-10 dB
C	2 dB
D	-20 dBm

30. - E6F11

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

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

31. - E7A05

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

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

32. - E7B05

What can be done to prevent unwanted oscillations in an RF power amplifier?

Select	Answer
A	Install parasitic suppressors and/or neutralize the stage
B	Tune both the input and output for maximum power
C	Tune the stage for maximum SWR
D	Use a phase inverter in the output filter

33. - E7C01

How are the capacitors and inductors of a low-pass filter Pi-network arranged between the network's input and output?

Select	Answer
A	A capacitor is connected between the input and ground, another capacitor is connected between the output and ground, and an inductor is connected between input and output
B	An inductor is connected between the input and ground, another inductor is connected between the output and ground, and a capacitor is connected between the input and output
C	Two inductors are in series between the input and output, and a capacitor is connected between the two inductors and ground
D	Two capacitors are in series between the input and output, and an inductor is connected between the two capacitors and ground

34. - E7D03

What device is typically used as a stable voltage reference in a linear voltage regulator?

Select	Answer
A	An SCR
B	A tunnel diode
C	A Zener diode
D	A varactor diode

35. - E7E03

What is a frequency discriminator stage in a FM receiver?

Select	Answer
A	A circuit for filtering two closely adjacent signals
B	An FM generator circuit
C	A circuit for detecting FM signals
D	An automatic band-switching circuit

36. - E7F13

What is the function of taps in a digital signal processing filter?

Select	Answer
A	Provide access for debugging software
B	Provide incremental signal delays for filter algorithms
C	Select the point at which baseband signals are generated
D	To reduce excess signal pressure levels

37. - E7G03

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

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

38. - E7H15

Which of these functions can be performed by a phase-locked loop?

Select	Answer
A	Frequency synthesis, FM demodulation
B	Wide-band AF and RF power amplification
C	Photovoltaic conversion, optical coupling
D	Comparison of two digital input signals, digital pulse counter

39. - E8A11

Which of the following is a measure of the quality of an analog-to-digital converter?

Select	Answer
A	Peak envelope power
B	Total harmonic distortion
C	Power factor
D	Reciprocal mixing

40. - E8B05

What is the deviation ratio of an FM-phone signal having a maximum frequency swing of plus-or-minus 5 kHz when the maximum modulation frequency is 3 kHz?

Select	Answer
A	1.67
B	0.6
C	60
D	0.167

41. - E8C01

How is Forward Error Correction implemented?

Select	Answer
A	By the receiving station repeating each block of three data characters
B	By varying the frequency shift of the transmitted signal according to a predefined algorithm
C	By transmitting extra data that may be used to detect and correct transmission errors
D	By transmitting a special algorithm to the receiving station along with the data characters

42. - E8D04

What is the primary effect of extremely short rise or fall time on a CW signal?

Select	Answer
A	More difficult to copy
B	Limits data speed
C	The generation of key clicks
D	The generation of RF harmonics

43. - E9A12

How much gain does an antenna have compared to a 1/2-wavelength dipole when it has 6 dB gain over an isotropic antenna?

Select	Answer
A	3.85 dB
B	6.0 dB
C	8.15 dB
D	2.79 dB

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	18 dB
D	14 dB

45. - E9C06

What is the effect of adding a terminating resistor to a rhombic antenna?

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

46. - E9D09

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

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

47. - E9E09

Which of the following is used to shunt-feed a grounded tower at its base?

Select	Answer
A	All these choices are correct
B	Double-bazooka match
C	Hairpin match
D	Gamma match

48. - E9F07

How does ladder line compare to small-diameter coaxial cable such as RG-58 at 50 MHz?

Select	Answer
A	Lower loss
B	Higher SWR
C	Lower velocity factor
D	Smaller reflection coefficient

49. - E9G01

Which of the following can be calculated using a Smith chart?

Select	Answer
A	Radiation resistance
B	Impedance along transmission lines
C	Antenna radiation pattern
D	Radio propagation

50. - E9H07

Why is RF attenuation used when direction-finding?

Select	Answer
A	To compensate for isotropic directivity and the antenna effect of feed lines
B	To increase receiver sensitivity
C	To prevent receiver overload which reduces pattern nulls
D	To narrow the receiver bandwidth

Figure E9-1