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

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1. - E0A05

What is one of the potential hazards of operating in the amateur radio microwave bands?

Select	Answer
A	The extremely high frequency energy can damage the joints of antenna structures
B	The high gain antennas commonly used can result in high exposure levels
C	Microwaves are ionizing radiation
D	Microwaves often travel long distances by ionospheric reflection

2. - E1A05

What is the maximum power output permitted on the 60 meter band?

Select	Answer
A	50 watts PEP effective radiated power relative to an isotropic radiator
B	50 watts PEP effective radiated power relative to a dipole
C	100 watts PEP effective radiated power relative to the gain of a half-wave dipole
D	100 watts PEP effective radiated power relative to an isotropic radiator

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	Use of wireless devices in a vehicle is exempt from regulation
C	Reasonable accommodations of amateur radio must be made
D	Amateur radio operations must be permitted in any private residence

4. - E1C14

How long must an operator wait after filing a notification with the Utilities Technology Council (UTC) before operating on the 2200 meter or 630 meter band?

Select	Answer
A	Operators may operate after 30 days, providing they have not been told that their station is within 1 km of PLC systems using those frequencies
B	Operators must not operate until approval is received
C	Operators may not operate until a test signal has been transmitted in coordination with the local power company
D	Operations may commence immediately, and may continue unless interference is reported by the UTC

5. - E1D10

Which amateur stations are eligible to be telecommand stations of space stations (subject to the privileges of the class of operator license held by the control operator of the station)?

Select	Answer
A	All these choices are correct
B	Any amateur station so designated by the ITU
C	Any amateur station designated by NASA
D	Any amateur station so designated by the space station licensee

6. - E1E10

What must the administering VEs do after the administration of a successful examination for an amateur operator license?

Select	Answer
A	They must collect and send the documents to the NCVEC for grading
B	They must submit the application document to the coordinating VEC according to the coordinating VEC instructions
C	They must collect and submit the documents to the coordinating VEC for grading
D	They must collect and send the documents to the FCC according to instructions

7. - E1F08

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

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

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

9. - E2B07

What is the name of the signal component that carries color information in NTSC video?

Select	Answer
A	Chroma
B	Spectral intensity
C	Hue
D	Luminance

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 the call sign of the DX station three times, the words this is,then your call sign three times
D	Send your full call sign and grid square

11. - E2D10

How can an APRS station be used to help support a public service communications activity?

Select	Answer
A	All these choices are correct
B	An APRS station with a Global Positioning System unit can automatically transmit information to show a mobile station's position during the event
C	An APRS station with an emergency medical technician can automatically transmit medical data to the nearest hospital
D	APRS stations with General Personnel Scanners can automatically relay the participant numbers and time as they pass the check points

12. - E2E13

Which of these digital modes has the fastest data throughput under clear communication conditions?

Select	Answer
A	300 baud packet
B	AMTOR
C	PSK31
D	170 Hz shift, 45 baud RTTY

13. - E3A13

Which of these emission modes is best for auroral propagation?

Select	Answer
A	FM
B	RTTY
C	CW
D	SSB

14. - E3B12

What is the primary characteristic of chordal hop propagation?

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

15. - E3C11

What does VOACAP software model?

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

16. - E4A06

What is the effect of aliasing on a digital oscilloscope caused by setting the time base too slow?

Select	Answer
A	All signals will have a DC offset
B	Excessive blanking occurs, which prevents display of the signal
C	A false, jittery low-frequency version of the signal is displayed
D	Calibration of the vertical scale is no longer valid

17. - E4B11

Which of the following can be measured with a vector network analyzer?

Select	Answer
A	Output impedance
B	All these choices are correct
C	Input impedance
D	Reflection coefficient

18. - E4C12

Which of the following has the largest effect on an SDR receiver's dynamic range?

Select	Answer
A	Anti-aliasing input filter bandwidth
B	Analog-to-digital converter sample width in bits
C	CPU register width in bits
D	RAM speed used for data storage

19. - E4D07

Which of the following reduces the likelihood of receiver desensitization?

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

20. - E4E02

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

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

21. - E5A06

What is the magnitude of the circulating current within the components of a parallel LC circuit at resonance?

Select	Answer
A	It equals 2 multiplied by pi, multiplied by frequency, multiplied by inductance
B	It equals 1 divided by the quantity 2 times pi, multiplied by the square root of inductance L multiplied by capacitance C
C	It is at a maximum
D	It is at a minimum

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	110 seconds
B	220 seconds
C	440 seconds
D	55 seconds

23. - E5C09

When using rectangular coordinates to graph the impedance of a circuit, what do the axes represent?

Select	Answer
A	The X axis represents the reactive component and the Y axis represents the resistive component
B	The X axis represents the resistive component and the Y axis represents the reactive component
C	The X axis represents the phase angle and the Y axis represents the magnitude
D	The X axis represents the magnitude and the Y axis represents the phase angle

24. - E5D04

Why are short connections used at microwave frequencies?

Select	Answer
A	To increase neutralizing resistance
B	To reduce phase shift along the connection
C	To reduce noise figure
D	To increase compensating capacitance

25. - E6A05

How does DC input impedance at the gate of a field-effect transistor compare with the DC input impedance of a bipolar transistor?

Select	Answer
A	An FET has higher input impedance
B	They are both high impedance
C	They are both low impedance
D	An FET has lower input impedance

26. - E6B06

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

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

27. - E6C04

Which of the following is an advantage of BiCMOS logic?

Select	Answer
A	Its simplicity results in much less expensive devices than standard CMOS
B	It is immune to electrostatic damage
C	All these choices are correct
D	It has the high input impedance of CMOS and the low output impedance of bipolar transistors

28. - E6D02

What is the equivalent circuit of a quartz crystal?

Select	Answer
A	Motional inductance and loss resistance in series, paralleled with motional capacitance and a capacitor representing electrode and stray capacitance
B	Motional capacitance, motional inductance, loss resistance, and a capacitor representing electrode and stray capacitance all in series
C	Motional capacitance, motional inductance, and loss resistance in series, all in parallel with a shunt capacitor representing electrode and stray capacitance
D	Motional capacitance, motional inductance, loss resistance, and a capacitor representing electrode and stray capacitance all in parallel

29. - E6E03

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

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

30. - E6F07

What is a solid-state relay?

Select	Answer
A	A relay using transistors to drive the relay coil
B	A device that uses semiconductors to implement the functions of an electromechanical relay
C	A mechanical relay that latches in the on or off state each time it is pulsed
D	A semiconductor passive delay line

31. - E7A11

What type of logic defines "1" as a high voltage?

Select	Answer
A	Assertive Logic
B	Positive Logic
C	Reverse Logic
D	Negative logic

32. - E7B11

In Figure E7-1, what is the purpose of R3?

Select	Answer
A	Emitter bypass
B	Output load resistor
C	Self bias
D	Fixed bias

33. - E7C09

What is a crystal lattice filter?

Select	Answer
A	A filter with narrow bandwidth and steep skirts made using quartz crystals
B	A power supply filter made with interlaced quartz crystals
C	An audio filter made with four quartz crystals that resonate at 1 kHz intervals
D	A filter using lattice-shaped quartz crystals for high-Q performance

34. - E7D03

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

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

35. - E7E01

Which of the following can be used to generate FM phone emissions?

Select	Answer
A	A reactance modulator on the final amplifier
B	A reactance modulator on the oscillator
C	A balanced modulator on the audio amplifier
D	A balanced modulator on the oscillator

36. - E7F03

What type of digital signal processing filter is used to generate an SSB signal?

Select	Answer
A	A notch filter
B	A Hilbert-transform filter
C	An elliptical filter
D	An adaptive filter

37. - E7G08

How does the gain of an ideal operational amplifier vary with frequency?

Select	Answer
A	It does not vary with frequency
B	It increases linearly with increasing frequency
C	It decreases linearly with increasing frequency
D	It decreases logarithmically with increasing frequency

38. - E7H12

Which of the following must be done to ensure that a crystal oscillator provides the frequency specified by the crystal manufacturer?

Select	Answer
A	Bias the crystal at a specified voltage
B	Provide the crystal with a specified parallel inductance
C	Bias the crystal at a specified current
D	Provide the crystal with a specified parallel capacitance

39. - E8A08

Why would a direct or flash conversion analog-to-digital converter be useful for a software defined radio?

Select	Answer
A	All these choices are correct
B	Very low power consumption decreases frequency drift
C	Very high speed allows digitizing high frequencies
D	Immunity to out-of-sequence coding reduces spurious responses

40. - E8B04

What is the modulation index of an FM-phone signal having a maximum carrier deviation of plus or minus 6 kHz when modulated with a 2 kHz modulating frequency?

Select	Answer
A	3
B	6000
C	2000
D	1/3

41. - E8C06

What is the bandwidth of a 170-hertz shift, 300-baud ASCII transmission?

Select	Answer
A	0.5 kHz
B	0.1 Hz
C	1.0 kHz
D	0.3 kHz

42. - E8D03

How does the spread spectrum technique of frequency hopping work?

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

43. - E9A07

What is the effective isotropic radiated power of a repeater station with 200 watts transmitter power output, 2 dB feed line loss, 2.8 dB duplexer loss, 1.2 dB circulator loss, and 7 dBi antenna gain?

Select	Answer
A	63.2 watts
B	159 watts
C	632 watts
D	252 watts

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 of the ionosphere where radiated power is not refracted
C	The region where radiated field strengths are constant
D	The region where radiated power dissipates over a specified time period

45. - E9C02

What is the radiation pattern of two 1/4-wavelength vertical antennas spaced 1/4 wavelength apart and fed 90 degrees out of phase?

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

46. - E9D04

Why should an HF mobile antenna loading coil have a high ratio of reactance to resistance?

Select	Answer
A	To swamp out harmonics
B	To lower the radiation angle
C	To minimize losses
D	To minimize the Q

47. - E9E06

Which of these feed line impedances would be suitable for constructing a quarter-wave Q-section for matching a 100-ohm loop to 50-ohm feed line?

Select	Answer
A	450 ohms
B	75 ohms
C	62 ohms
D	50 ohms

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 high impedance
B	The same as the output impedance of the generator
C	Very low impedance
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	Resistance and voltage
B	Reactance and voltage
C	Voltage and impedance
D	Resistance and reactance

50. - E9H11

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

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

Figure E7-1