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. - E0A11

Which of the following injuries can result from using high-power UHF or microwave transmitters?

Select	Answer
A	Localized heating of the body from RF exposure in excess of the MPE limits
B	Ingestion of ozone gas from the cooling system
C	Hearing loss caused by high voltage corona discharge
D	Blood clotting from the intense magnetic field

2. - E1A13

Who must be in physical control of the station apparatus of an amateur station aboard any vessel or craft that is documented or registered in the United States?

Select	Answer
A	Only a person with an FCC Marine Radio license grant
B	Any person named in an amateur station license grant or a person holding an unrestricted Radiotelephone Operator Permit
C	Only a person named in an amateur station license grant
D	Any person holding an FCC issued amateur license or who is authorized for alien reciprocal operation

3. - E1B11

What does PRB-1 require of regulations affecting amateur radio?

Select	Answer
A	No limitations may be placed on antenna size or placement
B	Reasonable accommodations of amateur radio must be made
C	Amateur radio operations must be permitted in any private residence
D	Use of wireless devices in a vehicle is exempt from regulation

4. - E1C12

On what portion of the 630 meter band are phone emissions permitted?

Select	Answer
A	Only the top 3 kHz
B	None
C	The entire band
D	Only the bottom 3 kHz

5. - E1D09

Which UHF amateur bands have frequencies authorized for space stations?

Select	Answer
A	70 cm and 33 cm
B	70 cm only
C	33 cm and 13 cm
D	70 cm and 13 cm

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

7. - E1F07

When may an amateur station send a message to a business?

Select	Answer
A	When the total money involved does not exceed $25
B	When the control operator is employed by the FCC or another government agency
C	When neither the amateur nor his or her employer has a pecuniary interest in the communications
D	When transmitting international third-party communications

8. - E2A13

Which of the following techniques is normally used by low Earth orbiting digital satellites to relay messages around the world?

Select	Answer
A	Store-and-forward
B	Node hopping
C	Digipeating
D	Multi-satellite relaying

9. - E2B02

How many horizontal lines make up a fast-scan (NTSC) television frame?

Select	Answer
A	60
B	30
C	525
D	1080

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 middle of the band, usually 25 kHz above the national calling frequency
B	In the weak signal segment of the band, with most of the activity near the 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. - E2D11

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

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

12. - E2E11

What is the difference between direct FSK and audio FSK?

Select	Answer
A	Direct FSK can transmit faster baud rates
B	Direct FSK occupies less bandwidth
C	Direct FSK applies the data signal to the transmitter VFO, while AFSK transmits tones via phone
D	Only direct FSK can be decoded by computer

13. - E3A10

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

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

14. - E3B07

What happens to linearly polarized radio waves that split into ordinary and extraordinary waves in the ionosphere?

Select	Answer
A	They are bent toward the magnetic poles
B	They become depolarized
C	They become phase locked
D	They become elliptically polarized

15. - E3C01

What does the radio communication term "ray tracing" describe?

Select	Answer
A	The process in which an electronic display presents a pattern
B	Modeling a radio wave's path through the ionosphere
C	Determining the radiation pattern from an array of antennas
D	Evaluating high voltage sources for x-rays

16. - E4A10

Which of the following displays multiple digital signal states simultaneously?

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

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

18. - E4C09

Which of the following choices is a good reason for selecting a high frequency for the design of the IF in a superheterodyne HF or VHF communications receiver?

Select	Answer
A	Improved receiver noise figure
B	Fewer components in the receiver
C	Easier for front-end circuitry to eliminate image responses
D	Reduced drift

19. - E4D08

What causes intermodulation in an electronic circuit?

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

20. - E4E02

Which of the following types of noise can often be reduced with a digital signal processing noise filter?

Select	Answer
A	All these choices are correct
B	Power line noise
C	Ignition noise
D	Broadband white noise

21. - E5A10

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

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

22. - E5B08

What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 100 ohms, R is 100 ohms, and XL is 75 ohms?

Select	Answer
A	76 degrees with the voltage lagging the current
B	76 degrees with the voltage leading the current
C	14 degrees with the voltage lagging the current
D	14 degrees with the voltage leading the current

23. - E5C12

Which point on Figure E5-1 best represents the impedance of a series circuit consisting of a 300-ohm resistor and a 19-picofarad capacitor at 21.200 MHz?

Select	Answer
A	Point 8
B	Point 1
C	Point 3
D	Point 7

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	0.707
B	1.0
C	0.5
D	0.866

25. - E6A09

What is a depletion-mode FET?

Select	Answer
A	Any FET without a channel
B	Any FET for which holes are the majority carriers
C	An FET that has no current flow between source and drain when no gate voltage is applied
D	An FET that exhibits a current flow between source and drain when no gate voltage is applied

26. - E6B09

What is a common use for point-contact diodes?

Select	Answer
A	As an RF detector
B	As a constant voltage source
C	As a high-voltage rectifier
D	As a constant current source

27. - E6C06

Why do CMOS digital integrated circuits have high immunity to noise on the input signal or power supply?

Select	Answer
A	Large bypass capacitance is inherent
B	The input switching threshold is about two times the power supply voltage
C	The input switching threshold is about one-half the power supply voltage
D	Bandwidth is very limited

28. - E6D11

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

Select	Answer
A	Ceramic
B	Ferrite
C	Brass
D	Powdered iron

29. - E6E12

Why are DIP through-hole package ICs not typically used at UHF and higher frequencies?

Select	Answer
A	Unsuitable for combining analog and digital signals
B	Epoxy coating is conductive above 300 MHz
C	Excessive lead length
D	Too many pins

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. - E7A01

Which circuit is bistable?

Select	Answer
A	An AND gate
B	A flip-flop
C	An OR gate
D	A bipolar amplifier

32. - E7B08

How can an RF power amplifier be neutralized?

Select	Answer
A	By reducing the driving power
B	By increasing the driving power
C	By feeding an in-phase component of the output back to the input
D	By feeding a 180-degree out-of-phase portion of the output back to the input

33. - E7C07

Which describes a Pi-L-network used for matching a vacuum tube final amplifier to a 50-ohm unbalanced output?

Select	Answer
A	A Phase Inverter Load network
B	A network with only three discrete parts
C	A matching network in which all components are isolated from ground
D	A Pi-network with an additional series inductor on the output

34. - E7D07

What is the purpose of C2 in the circuit shown in Figure E7-2?

Select	Answer
A	It is a brute force filter for the output
B	It bypasses rectifier output ripple around D1
C	To self-resonate at the hum frequency
D	To provide fixed DC bias for Q1

35. - E7E06

Why is de-emphasis commonly used in FM communications receivers?

Select	Answer
A	For higher efficiency
B	For compatibility with transmitters using phase modulation
C	To reduce impulse noise reception
D	To remove third-order distortion products

36. - E7F01

What is meant by direct digital conversion as applied to software defined radios?

Select	Answer
A	Incoming RF is digitized by an analog-to-digital converter without being mixed with a local oscillator signal
B	Incoming RF is converted to a control voltage for a voltage controlled oscillator
C	A switching mixer is used to generate I and Q signals directly from the RF input
D	Software is converted from source code to object code during operation of the receiver

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	94
B	47
C	0.21
D	24

38. - E7H11

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

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

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

40. - 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 data streams share the same channel by transmitting time of transmission as the sub-carrier
C	Two or more signals are arranged to share discrete time slots of a data transmission
D	Two or more data streams are assigned to discrete sub-carriers on an FM transmitter

41. - E8C10

How may data rate be increased without increasing bandwidth?

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

42. - E8D04

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

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

43. - E9A13

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

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

44. - E9B06

What is the elevation angle of peak response in the antenna radiation pattern shown in Figure E9-2?

Select	Answer
A	45 degrees
B	25 degrees
C	75 degrees
D	7.5 degrees

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

46. - E9D07

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

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

47. - E9E03

What is the name of the matching system that uses a section of transmission line connected in parallel with the feed line at or near the feed point?

Select	Answer
A	The delta match
B	The gamma match
C	The omega match
D	The stub match

48. - E9F04

What impedance does a 1/2-wavelength transmission line present to a generator when the line is shorted at the far end?

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

49. - E9G01

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

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

50. - E9H11

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

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

Figure E5-1

Figure E7-2

Figure E9-2