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

Logging in (or registering) will help the system to select questions that you need to focus on.

1. - 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	Beryllium Oxide
B	Zinc oxide
C	Mica
D	Uranium Hexafluoride

2. - E1A01

Which of the following carrier frequencies is illegal for LSB AFSK emissions on the 17 meter band RTTY and data segment of 18.068 to 18.110 MHz?

Select	Answer
A	18.107 MHz
B	18.110 MHz
C	18.100 MHz
D	18.068 MHz

3. - E1B07

To what type of regulations does PRB-1 apply?

Select	Answer
A	Use of wireless devices in vehicles
B	Homeowners associations
C	State and local zoning
D	FAA tower height limits

4. - E1C01

What is the maximum bandwidth for a data emission on 60 meters?

Select	Answer
A	170 Hz
B	1.5 kHz
C	60 Hz
D	2.8 kHz

5. - E1D03

What is a space telecommand station?

Select	Answer
A	An amateur station that transmits communications to initiate, modify or terminate functions of a space station
B	An amateur station located in a satellite or a balloon more than 50 kilometers above the surface of the Earth
C	An amateur station located on the surface of the Earth for communication with other Earth stations by means of Earth satellites
D	An amateur station that receives telemetry from a satellite or balloon more than 50 kilometers above the surface of the Earth

6. - E1E06

Who is responsible for the proper conduct and necessary supervision during an amateur operator license examination session?

Select	Answer
A	The VEC coordinating the session
B	Each administering VE
C	The FCC
D	The VE session manager

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

8. - E2A07

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

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

9. - E2B04

How is color information sent in analog SSTV?

Select	Answer
A	Color is sent in a color burst at the end of each line
B	Color lines are sent sequentially
C	Color information is sent on a 2.8 kHz subcarrier
D	Color is amplitude modulated on the frequency modulated intensity signal

10. - E2C06

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

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

11. - E2D09

What type of modulation is used for JT65 contacts?

Select	Answer
A	IEEE 802.11
B	PSK
C	RTTY
D	Multi-tone AFSK

12. - E2E09

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

Select	Answer
A	MT63
B	PSK31
C	PACTOR
D	RTTY

13. - E3A05

Tropospheric propagation of microwave signals often occurs in association with what phenomenon?

Select	Answer
A	Sprites and jets
B	Warm and cold fronts
C	Grayline
D	Lightning discharges

14. - E3B06

Which of the following amateur bands most frequently provides long-path propagation?

Select	Answer
A	10 meters
B	20 meters
C	6 meters
D	80 meters

15. - E3C11

What does VOACAP software model?

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

16. - E4A10

Which of the following displays multiple digital signal states simultaneously?

Select	Answer
A	Modulation monitor
B	Bit error rate tester
C	Network analyzer
D	Logic analyzer

17. - E4B10

Which of the following methods measures intermodulation distortion in an SSB transmitter?

Select	Answer
A	Modulate the transmitter using two RF signals having harmonically related frequencies and observe the RF output with a logic analyzer
B	Modulate the transmitter using two AF signals having non-harmonically related frequencies and observe the RF output with a spectrum analyzer
C	Modulate the transmitter using two RF signals having non-harmonically related frequencies and observe the RF output with a spectrum analyzer
D	Modulate the transmitter using two AF signals having harmonically related frequencies and observe the RF output with a peak reading wattmeter

18. - E4C03

What is the term for the suppression in an FM receiver of one signal by another stronger signal on the same frequency?

Select	Answer
A	Desensitization
B	Frequency discrimination
C	Cross-modulation interference
D	Capture effect

19. - E4D08

What causes intermodulation in an electronic circuit?

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

20. - E4E07

Which of the following can cause shielded cables to radiate or receive interference?

Select	Answer
A	Common-mode currents on the shield and conductors
B	Use of braided shielding material
C	Low inductance ground connections at both ends of the shield
D	Tying all ground connections to a common point resulting in differential-mode currents in the shield

21. - E5A01

What can cause the voltage across reactances in a series RLC circuit to be higher than the voltage applied to the entire circuit?

Select	Answer
A	Capacitance
B	Resistance
C	Conductance
D	Resonance

22. - 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

23. - E5C05

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

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

24. - E5D15

What is the power factor of an RL circuit having a 45-degree phase angle between the voltage and the current?

Select	Answer
A	0.5
B	0.707
C	1.0
D	0.866

25. - E6A03

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

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

26. - E6B03

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

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

27. - E6C09

What is a Programmable Logic Device (PLD)?

Select	Answer
A	A programmable collection of logic gates and circuits in a single integrated circuit
B	A logic circuit that can be modified during use
C	Programmable equipment used for testing digital logic integrated circuits
D	A type of transistor whose gain can be changed by digital logic circuits

28. - E6D06

What core material property determines the inductance of an inductor?

Select	Answer
A	Resistance
B	Thermal impedance
C	Permeability
D	Reactivity

29. - E6E03

Which of the following materials is likely to provide the highest frequency of operation when used in MMICs?

Select	Answer
A	Silicon nitride
B	Silicon
C	Gallium nitride
D	Silicon dioxide

30. - E6F03

What is the most common configuration of an optoisolator or optocoupler?

Select	Answer
A	A frequency modulated helium-neon laser
B	A lens and a photomultiplier
C	An amplitude modulated helium-neon laser
D	An LED and a phototransistor

31. - E7A05

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

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

32. - E7B17

Why are odd-order rather than even-order intermodulation distortion products of concern in linear power amplifiers?

Select	Answer
A	Because they are relatively far in frequency from the desired signal
B	Because they maintain the sidebands, thus causing multiple duplicate signals
C	Because they invert the sidebands causing distortion
D	Because they are relatively close in frequency to the desired signal

33. - E7C12

What is one advantage of a Pi-matching network over an L-matching network consisting of a single inductor and a single capacitor?

Select	Answer
A	The Q of Pi-networks can be controlled
B	Pi-networks are more stable
C	Pi-networks provide balanced input and output
D	L-networks cannot perform impedance transformation

34. - E7D12

What is the dropout voltage of an analog voltage regulator?

Select	Answer
A	Maximum output voltage drops when the input voltage is varied over its specified range
B	Minimum input voltage for rated power dissipation
C	Minimum input-to-output voltage required to maintain regulation
D	Maximum that the output voltage may decrease at rated load

35. - E7E09

What occurs when an excessive amount of signal energy reaches a mixer circuit?

Select	Answer
A	Spurious mixer products are generated
B	Mixer blanking occurs
C	A beat frequency is generated
D	Automatic limiting occurs

36. - E7F11

What sets the minimum detectable signal level for a direct-sampling SDR receiver in the absence of atmospheric or thermal noise?

Select	Answer
A	Reference voltage level and sample width in bits
B	Missing codes and jitter
C	Sample clock phase noise
D	Data storage transfer rate

37. - E7G07

What magnitude of voltage gain can be expected from the circuit in Figure E73 when R1 is 10 ohms and RF is 470 ohms?

Select	Answer
A	24
B	94
C	47
D	0.21

38. - E7H01

What are three oscillator circuits used in amateur radio equipment?

Select	Answer
A	Taft, Pierce and negative feedback
B	Pierce, Fenner and Beane
C	Colpitts, Hartley and Pierce
D	Taft, Hartley and Pierce

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

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	60
C	0.167
D	0.6

41. - E8C07

What is the bandwidth of a 4800-Hz frequency shift, 9600-baud ASCII FM transmission?

Select	Answer
A	9.6 kHz
B	5.76 kHz
C	15.36 kHz
D	4.8 kHz

42. - E8D02

What spread spectrum communications technique uses a high-speed binary bit stream to shift the phase of an RF carrier?

Select	Answer
A	Binary phase-shift keying
B	Phase compandored spread spectrum
C	Direct sequence
D	Frequency hopping

43. - E9A09

What is antenna efficiency?

Select	Answer
A	Radiation resistance divided by total resistance
B	Effective radiated power divided by transmitter output
C	Radiation resistance divided by transmission resistance
D	Total resistance divided by radiation resistance

44. - E9B10

What is the principle of a Method of Moments analysis?

Select	Answer
A	A wire is modeled as a single sine-wave voltage source
B	A wire is modeled as a series of segments, each having a distinct value of voltage across it
C	A wire is modeled as a single sine-wave current generator
D	A wire is modeled as a series of segments, each having a uniform value of current

45. - E9C09

Which of the following describes a G5RV antenna?

Select	Answer
A	A multi-band trap antenna
B	A phased array antenna consisting of multiple loops
C	A wide band dipole using shorted coaxial cable for the radiating elements and fed with a�4:1 balun
D	A multi-band dipole antenna fed with coax and a balun through a selected length of open wire transmission line

46. - E9D09

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

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

47. - E9E07

What parameter describes the interactions at the load end of a mismatched transmission line?

Select	Answer
A	Reflection coefficient
B	Characteristic impedance
C	Dielectric constant
D	Velocity factor

48. - E9F07

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

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

49. - 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	Prime axis
B	Impedance axis
C	Polar axis
D	Reactance axis

50. - E9H10

How can the output voltage of a multiple-turn receiving loop antenna be increased?

Select	Answer
A	By increasing the number of turns and/or the area
B	By reducing the permeability of the loop shield
C	By winding adjacent turns in opposing directions
D	By utilizing high impedance wire for the coupling loop

Figure E9-3