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	Microwaves are ionizing radiation
C	Microwaves often travel long distances by ionospheric reflection
D	The high gain antennas commonly used can result in high exposure levels

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	18.068 MHz
B	18.107 MHz
C	18.100 MHz
D	18.110 MHz

3. - E1B09

Which amateur stations may be operated under RACES rules?

Select	Answer
A	Any FCC-licensed amateur station participating in the Military Auxiliary Radio System (MARS)
B	Any FCC-licensed amateur station certified by the responsible civil defense organization for the area served
C	Only those club stations licensed to Amateur Extra Class operators
D	Any FCC-licensed amateur station except a Technician Class

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 not operate until a test signal has been transmitted in coordination with the local power company
B	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
C	Operators must not operate until approval is received
D	Operations may commence immediately, and may continue unless interference is reported by the UTC

5. - E1D03

What is a space telecommand station?

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

6. - E1E05

What is the minimum passing score on all amateur operator license examinations?

Select	Answer
A	Minimum passing score of 70%
B	Minimum passing score of 77%
C	Minimum passing score of 80%
D	Minimum passing score of 74%

7. - E1F04

Which of the following geographic descriptions approximately describes "Line A"?

Select	Answer
A	A line roughly parallel to and south of the border between the U.S. and Canada
B	A line roughly parallel to and north of the border between the U.S. and Mexico
C	A line roughly parallel to and west of the U.S. Atlantic coastline
D	A line roughly parallel to and east of the U.S. Pacific coastline

8. - E2A02

Which of the following occurs when a satellite is using an inverting linear transponder?

Select	Answer
A	Signal position in the band is reversed
B	Doppler shift is reduced because the uplink and downlink shifts are in opposite directions
C	All these choices are correct
D	Upper sideband on the uplink becomes lower sideband on the downlink, and vice versa

9. - E2B09

What hardware, other than a receiver with SSB capability and a suitable computer, is needed to decode SSTV using Digital Radio Mondiale (DRM)?

Select	Answer
A	A special front end limiter
B	A special IF converter
C	No other hardware is needed
D	A special notch filter to remove synchronization pulses

10. - E2C08

Which of the following contacts may be confirmed through the U.S. QSL bureau system?

Select	Answer
A	Contacts using tactical call signs
B	Repeater contacts between U.S. club members
C	Special event contacts between stations in the U.S.
D	Contacts between a U.S. station and a non-U.S. station

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. - E2E01

Which of the following types of modulation is common for data emissions below 30 MHz?

Select	Answer
A	DTMF tones modulating an FM signal
B	Pulse modulation
C	FSK
D	Spread spectrum

13. - E3A02

What characterizes libration fading of an EME signal?

Select	Answer
A	A slow change in the pitch of the CW signal
B	A gradual loss of signal as the sun rises
C	A fluttery irregular fading
D	The returning echo is several hertz lower in frequency than the transmitted signal

14. - E3B03

What is the best time of day for transequatorial propagation?

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

15. - E3C02

What is indicated by a rising A or K index?

Select	Answer
A	Decreasing disruption of the geomagnetic field
B	An increase in the critical frequency
C	Increasing disruption of the geomagnetic field
D	Higher levels of solar UV radiation

16. - E4A02

Which of the following parameters does a spectrum analyzer display on the vertical and horizontal axes?

Select	Answer
A	SWR and frequency
B	SWR and time
C	RF amplitude and frequency
D	RF amplitude and time

17. - E4B07

What do the subscripts of S parameters represent?

Select	Answer
A	The relative time between measurements
B	Frequency order of the measurements
C	Relative quality of the data
D	The port or ports at which measurements are made

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

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	146.10 MHz and 147.30 MHz
C	146.34 MHz and 146.61 MHz
D	146.88 MHz and 146.34 MHz

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	All these choices are correct
C	Ignition noise
D	Power line noise

21. - E5A08

What is the phase relationship between the current through and the voltage across a series resonant circuit at resonance?

Select	Answer
A	The voltage and current are in phase
B	The current leads the voltage by 90 degrees
C	The voltage leads the current by 90 degrees
D	The voltage and current are 180 degrees out of phase

22. - E5B07

What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 500 ohms, R is 1 kilohm, and XL is 250 ohms?

Select	Answer
A	14.0 degrees with the voltage leading the current
B	14.0 degrees with the voltage lagging the current
C	68.2 degrees with the voltage lagging the current
D	68.2 degrees with the voltage leading the current

23. - E5C01

Which of the following represents capacitive reactance in rectangular notation?

Select	Answer
A	-jX
B	Delta
C	Omega
D	+jX

24. - E5D07

How many watts are consumed in a circuit having a power factor of 0.71 if the apparent power is 500VA?

Select	Answer
A	704 W
B	355 W
C	252 W
D	1.42 mW

25. - E6A04

What is the name given to an impurity atom that adds holes to a semiconductor crystal structure?

Select	Answer
A	Insulator impurity
B	N-type impurity
C	Acceptor impurity
D	Donor impurity

26. - E6B06

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

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

27. - E6C01

What is the function of hysteresis in a comparator?

Select	Answer
A	To allow the comparator to be used with AC input signals
B	To prevent input noise from causing unstable output signals
C	To cause the output to change states continually
D	To increase the sensitivity

28. - E6D08

What is one reason for using powdered-iron cores rather than ferrite cores in an inductor?

Select	Answer
A	Powdered-iron cores generally require fewer turns to produce a given inductance
B	Powdered-iron cores generally maintain their characteristics at higher currents
C	Powdered-iron cores use smaller diameter wire for the same inductance
D	Powdered-iron cores generally have greater initial permeability

29. - E6E02

Which of the following device packages is a through-hole type?

Select	Answer
A	DIP
B	PLCC
C	SOT
D	Ball grid array

30. - E6F09

What is the efficiency of a photovoltaic cell?

Select	Answer
A	The open-circuit voltage divided by the short-circuit current under full illumination
B	The relative fraction of light that is converted to current
C	Cost per kilowatt-hour generated
D	The output RF power divided by the input DC power

31. - E7A07

What logical operation does a NAND gate perform?

Select	Answer
A	It produces logic 1 at its output only when all inputs are logic 1
B	It produces logic 0 at its output only when all inputs are logic 0
C	It produces logic 0 at its output if some but not all inputs are logic 1
D	It produces logic 0 at its output only when all inputs are logic 1

32. - E7B16

What is the effect of intermodulation products in a linear power amplifier?

Select	Answer
A	Low efficiency
B	Creation of parasitic oscillations
C	Transmission of spurious signals
D	All these choices are correct

33. - E7C11

Which of the following describes a receiving filter's ability to reject signals occupying an adjacent channel?

Select	Answer
A	Noise factor
B	Passband ripple
C	Shape factor
D	Phase response

34. - E7D08

What type of circuit is shown in Figure E7-2?

Select	Answer
A	Monostable multivibrator
B	Grounded emitter amplifier
C	Switching voltage regulator
D	Linear voltage regulator

35. - E7E03

What is a frequency discriminator stage in a FM receiver?

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

36. - E7F08

What is the function of decimation?

Select	Answer
A	Reducing the effective sample rate by removing samples
B	Attenuating the signal
C	Removing unnecessary significant digits
D	Converting data to binary code decimal form

37. - E7G01

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

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

38. - E7H07

How can an oscillator's microphonic responses be reduced?

Select	Answer
A	Mechanically isolate the oscillator circuitry from its enclosure
B	Reduce noise on the oscillator's power supply
C	Increase the bias voltage
D	Use NP0 capacitors

39. - E8A11

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

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

40. - E8B09

What is deviation ratio?

Select	Answer
A	The ratio of the carrier center frequency to the audio modulating frequency
B	The ratio of the maximum carrier frequency deviation to the highest audio modulating frequency
C	The ratio of the audio modulating frequency to the center carrier frequency
D	The ratio of the highest audio modulating frequency to the average audio modulating frequency

41. - E8C03

Why should phase-shifting of a PSK signal be done at the zero crossing of the RF signal?

Select	Answer
A	To improve carrier suppression
B	All these choices are correct
C	To minimize bandwidth
D	To simplify modulation

42. - E8D10

What are some of the differences between the Baudot digital code and ASCII?

Select	Answer
A	Baudot uses 6 data bits per character, ASCII uses 7 or 8; Baudot has no letters/figures shift code, ASCII uses 2 letters/figures shift codes
B	Baudot uses 5 data bits per character, ASCII uses 7 or 8; Baudot uses 2 characters as letters/figures shift codes, ASCII has no letters/figures shift code
C	Baudot uses 4 data bits per character, ASCII uses 7 or 8; Baudot uses 1 character as a letters/figures shift code, ASCII has no letters/figures code
D	Baudot uses 7 data bits per character, ASCII uses 8; Baudot has no letters/figures shift code, ASCII uses 2 letters/figures shift codes

43. - E9A10

Which of the following improves the efficiency of a ground-mounted quarter-wave vertical antenna?

Select	Answer
A	Isolating the coax shield from ground
B	Shortening the radiating element
C	All these choices are correct
D	Installing a radial system

44. - E9B05

What type of antenna pattern is shown in Figure E9-2?

Select	Answer
A	Radiation resistance
B	Azimuth
C	Elevation
D	Polarization

45. - E9C01

What is the radiation pattern of two 1/4-wavelength vertical antennas spaced 1/2-wavelength apart and fed 180 degrees out of phase?

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

46. - E9D03

Where should a high Q loading coil be placed to minimize losses in a shortened vertical antenna?

Select	Answer
A	As close to the transmitter as possible
B	Near the center of the vertical radiator
C	At a voltage node
D	As low as possible on the vertical radiator

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	Hairpin match
C	Gamma match
D	Double-bazooka match

48. - E9F02

Which of the following has the biggest effect on the velocity factor of a transmission line?

Select	Answer
A	Dielectric materials used in the line
B	The line length
C	The center conductor resistivity
D	The termination impedance

49. - E9G04

What are the two families of circles and arcs that make up a Smith chart?

Select	Answer
A	Resistance and voltage
B	Resistance and reactance
C	Reactance and voltage
D	Voltage and impedance

50. - E9H09

What is a Pennant antenna?

Select	Answer
A	A small, vertically oriented receiving antenna consisting of a triangular loop terminated in approximately 900 ohms
B	A form of rhombic antenna terminated in a variable capacitor to provide frequency diversity
C	A four-element, high-gain vertical array invented by George Pennant
D	A stealth antenna built to look like a flagpole

Figure E7-2

Figure E9-2