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

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1. - E0A08

What does SAR measure?

Select	Answer
A	The rate at which RF energy is absorbed by the body
B	The rate of RF energy reflected from stationary terrain
C	Signal Amplification Rating
D	Synthetic Aperture Ratio of the human body

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

3. - E1B07

To what type of regulations does PRB-1 apply?

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

4. - E1C08

What is the maximum permissible duration of a remotely controlled station's transmissions if its control link malfunctions?

Select	Answer
A	10 minutes
B	3 minutes
C	30 seconds
D	5 minutes

5. - E1D06

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

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

6. - E1E06

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

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

7. - E1F08

Which of the following types of amateur station communications are prohibited?

Select	Answer
A	Communications that have religious content
B	Communications that have political content, except as allowed by the Fairness Doctrine
C	Communications in a language other than English
D	Communications transmitted for hire or material compensation, except as otherwise provided in the rules

8. - E2A07

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

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

9. - E2B06

What is vestigial sideband modulation?

Select	Answer
A	Amplitude modulation in which one complete sideband and a portion of the other are transmitted
B	A type of modulation in which one sideband is inverted
C	Spread spectrum modulation achieved by applying FM modulation following single sideband amplitude modulation
D	Narrow-band FM modulation achieved by filtering one sideband from the audio before frequency modulating the carrier

10. - E2C05

What is the function of a DX QSL Manager?

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

11. - E2D03

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

Select	Answer
A	Olivia
B	PACTOR III
C	MSK144
D	JT65

12. - E2E08

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

Select	Answer
A	Hellschreiber
B	AMTOR
C	RTTY
D	PACTOR

13. - E3A10

Which type of atmospheric structure can create a path for microwave propagation?

Select	Answer
A	Temperature inversion
B	Dust devil
C	The jet stream
D	Wind shear

14. - E3B12

What is the primary characteristic of chordal hop propagation?

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

15. - E3C03

Which of the following signal paths is most likely to experience high levels of absorption when the A index or K index is elevated?

Select	Answer
A	NVIS
B	Transequatorial
C	Sporadic E
D	Polar

16. - E4A11

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	Loosely couple the antenna and a dummy load to the analyzer
C	Loosely couple the analyzer near the antenna base
D	Connect the analyzer via a high-impedance transformer to the antenna

17. - E4B01

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

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

18. - E4C02

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

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

19. - E4D05

What transmitter frequencies would cause an intermodulation-product signal in a receiver tuned to 146.70 MHz when a nearby station transmits on 146.52 MHz?

Select	Answer
A	173.35 MHz and 139.40 MHz
B	146.34 MHz and 146.61 MHz
C	146.10 MHz and 147.30 MHz
D	146.88 MHz and 146.34 MHz

20. - E4E03

Which of the following signals might a receiver noise blanker be able to remove from desired signals?

Select	Answer
A	Signals that appear at one IF but not another
B	Signals that appear across a wide bandwidth
C	Signals that have a sharply peaked frequency distribution
D	Signals that are constant at all IF levels

21. - E5A15

Which of the following increases Q for inductors and capacitors?

Select	Answer
A	Higher self-resonant frequency
B	Lower reactance
C	Lower losses
D	Lower self-resonant frequency

22. - E5B12

What is admittance?

Select	Answer
A	The turns ratio of a transformer
B	The term for the gain of a field effect transistor
C	The inverse of impedance
D	The inverse of Q factor

23. - E5C04

What coordinate system is often used to display the resistive, inductive, and/or capacitive reactance components of impedance?

Select	Answer
A	Rectangular coordinates
B	Faraday grid
C	Maidenhead grid
D	Elliptical coordinates

24. - 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	80 watts
B	50 watts
C	400 watts
D	2000 watts

25. - E6A12

Why do many MOSFET devices have internally connected Zener diodes on the gates?

Select	Answer
A	To keep the gate voltage within specifications and prevent the device from overheating
B	To protect the substrate from excessive voltages
C	To reduce the chance of static damage to the gate
D	To provide a voltage reference for the correct amount of reverse-bias gate voltage

26. - E6B04

What type of semiconductor device is designed for use as a voltage-controlled capacitor?

Select	Answer
A	Varactor diode
B	Tunnel diode
C	Silicon-controlled rectifier
D	Zener diode

27. - E6C10

In Figure E6-3, what is the schematic symbol for a NOR gate?

Select	Answer
A	1
B	4
C	2
D	3

28. - E6D06

What core material property determines the inductance of an inductor?

Select	Answer
A	Reactivity
B	Thermal impedance
C	Resistance
D	Permeability

29. - E6E07

What type of transmission line is used for connections to MMICs?

Select	Answer
A	Miniature coax
B	Parallel wire
C	Circular waveguide
D	Microstrip

30. - 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

31. - E7A08

What logical operation does an OR gate perform?

Select	Answer
A	It produces logic 1 at its output if any or all inputs are logic 1
B	It produces logic 1 at its output if all inputs are logic 0
C	It only produces logic 0 at its output when all inputs are logic 1
D	It produces logic 0 at its output if all inputs are logic 1

32. - E7B12

What type of amplifier circuit is shown in Figure E7-1?

Select	Answer
A	Common base
B	Emitter follower
C	Common emitter
D	Common collector

33. - E7C04

How does an impedance-matching circuit transform a complex impedance to a resistive impedance?

Select	Answer
A	It introduces transconductance to cancel the reactive part of impedance
B	Reactive currents are dissipated in matched resistances
C	It cancels the reactive part of the impedance and changes the resistive part to a desired value
D	It introduces negative resistance to cancel the resistive part of impedance

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	Input voltage multiplied by input current
C	Output voltage multiplied by output current
D	Voltage difference from input to output multiplied by output current

35. - E7E03

What is a frequency discriminator stage in a FM receiver?

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

36. - E7F13

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

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

37. - E7G03

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

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

38. - E7H13

Which of the following is a technique for providing highly accurate and stable oscillators needed for microwave transmission and reception?

Select	Answer
A	Use a temperature-controlled high Q dielectric resonator
B	Use a rubidium stabilized reference oscillator
C	Use a GPS signal reference
D	All these choices are correct

39. - E8A06

What is the approximate ratio of PEP-to-average power in a typical single-sideband phone signal?

Select	Answer
A	100 to 1
B	25 to 1
C	1 to 1
D	2.5 to 1

40. - E8B06

What is the deviation ratio of an FM-phone signal having a maximum frequency swing of plus or minus 7.5 kHz when the maximum modulation frequency is 3.5 kHz?

Select	Answer
A	0.47
B	0.214
C	2.14
D	47

41. - E8C09

Which digital code allows only one bit to change between sequential code values?

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

42. - E8D09

What is considered an acceptable maximum IMD level for an idling PSK signal?

Select	Answer
A	-20 dB
B	+15 dB
C	-30 dB
D	+10 dB

43. - E9A13

What term describes station output, taking into account all gains and losses?

Select	Answer
A	Power factor
B	Effective radiated power
C	Apparent power
D	Half-power bandwidth

44. - E9B08

What is the far field of an antenna?

Select	Answer
A	The region where the shape of the antenna pattern is independent of distance
B	The region where radiated power dissipates over a specified time period
C	The region where radiated field strengths are constant
D	The region of the ionosphere where radiated power is not refracted

45. - E9C07

What is the approximate feed point impedance at the center of a two-wire folded dipole antenna?

Select	Answer
A	300 ohms
B	72 ohms
C	450 ohms
D	50 ohms

46. - E9D07

What is an advantage of using top loading in a shortened HF vertical antenna?

Select	Answer
A	Improved radiation efficiency
B	Higher losses
C	Greater structural strength
D	Lower Q

47. - E9E04

What is the purpose of the series capacitor in a gamma-type antenna matching network?

Select	Answer
A	To transform the antenna impedance to a higher value
B	To provide DC isolation between the feed line and the antenna
C	To provide a rejection notch that prevents the radiation of harmonics
D	To cancel the inductive reactance of the matching network

48. - E9F06

What is the approximate physical length of an air-insulated, parallel conductor transmission line that is electrically 1/2 wavelength long at 14.10 MHz?

Select	Answer
A	7.0 meters
B	10.6 meters
C	13.3 meters
D	8.5 meters

49. - E9G03

Which of the following is often determined using a Smith chart?

Select	Answer
A	Impedance and SWR values in transmission lines
B	Satellite azimuth and elevation bearings
C	Beam headings and radiation patterns
D	Trigonometric functions

50. - E9H11

What feature of a cardioid pattern antenna makes it useful for direction finding?

Select	Answer
A	High radiation angle
B	Broadband response
C	A very sharp single null
D	A very sharp peak

Figure E6-3

Figure E7-1