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

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1. - E0A02

When evaluating RF exposure levels from your station at a neighbor's home, what must you do?

Select	Answer
A	Ensure signals from your station are less than the controlled Maximum Permitted Emission (MPE) limits
B	Ensure signals from your station are less than the uncontrolled Maximum Permitted Exposure (MPE) limits
C	Ensure signals from your station are less than the controlled Maximum Permitted Exposure (MPE) limits
D	Ensure signals from your station are less than the uncontrolled Maximum Permitted Emission (MPE) limits

2. - E1A07

What is the maximum power permitted on the 2200 meter band?

Select	Answer
A	1 watt EIRP (Equivalent isotropic radiated power)
B	50 watts PEP
C	5 watts EIRP (Equivalent isotropic radiated power)
D	100 watts PEP

3. - E1B09

Which amateur stations may be operated under RACES rules?

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

4. - E1C01

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

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

5. - E1D06

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

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

6. - E1E04

Which of the following best describes the Volunteer Examiner accreditation process?

Select	Answer
A	The procedure by which a VEC confirms that the VE applicant meets FCC requirements to serve as an examiner
B	The prospective VE obtains accreditation from the FCC
C	The amateur operator applying must pass a VE examination administered by the FCC Enforcement Bureau
D	Each General, Advanced and Amateur Extra Class operator is automatically accredited as a VE when the license is granted

7. - E1F09

Which of the following conditions apply when transmitting spread spectrum emissions?

Select	Answer
A	All these choices are correct
B	A station transmitting SS emission must not cause harmful interference to other stations employing other authorized emissions
C	The transmitting station must be in an area regulated by the FCC or in a country that permits SS emissions
D	The transmission must not be used to obscure the meaning of any communication

8. - E2A07

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

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

9. - E2B07

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

Select	Answer
A	Hue
B	Chroma
C	Luminance
D	Spectral intensity

10. - E2C07

What is the Cabrillo format?

Select	Answer
A	The rules of order for meetings between contest sponsors
B	A method of exchanging information during a contest QSO
C	The most common set of contest rules
D	A standard for submission of electronic contest logs

11. - E2D02

Which of the following is a good technique for making meteor scatter contacts?

Select	Answer
A	Use of special digital modes
B	15-second timed transmission sequences with stations alternating based on location
C	All these choices are correct
D	Short transmissions with rapidly repeated call signs and signal reports

12. - E2E11

What is the difference between direct FSK and audio FSK?

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

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. - E3B02

What is the approximate maximum range for signals using transequatorial propagation?

Select	Answer
A	2500 miles
B	1000 miles
C	7500 miles
D	5000 miles

15. - E3C13

What type of polarization is best for ground-wave propagation?

Select	Answer
A	Elliptical
B	Circular
C	Horizontal
D	Vertical

16. - E4A04

How is the compensation of an oscilloscope probe typically adjusted?

Select	Answer
A	A DC voltage standard is displayed and the probe is adjusted until the displayed voltage is accurate
B	A high frequency sine wave is displayed and the probe is adjusted for maximum amplitude
C	A frequency standard is displayed and the probe is adjusted until the deflection time is accurate
D	A square wave is displayed and the probe is adjusted until the horizontal portions of the displayed wave are as nearly flat as possible

17. - E4B07

What do the subscripts of S parameters represent?

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

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	Reduced drift
C	Easier for front-end circuitry to eliminate image responses
D	Fewer components in the receiver

19. - E4D03

How can intermodulation interference between two repeaters occur?

Select	Answer
A	When the signals from the transmitters are reflected out of phase from airplanes passing overhead
B	When the repeaters are in close proximity and the signals mix in the final amplifier of one or both transmitters
C	When the signals from the transmitters are reflected in phase from airplanes passing overhead
D	When the repeaters are in close proximity and the signals cause feedback in the final amplifier of one or both transmitters

20. - E4E11

What could cause local AM broadcast band signals to combine to generate spurious signals in the MF or HF bands?

Select	Answer
A	Your station receiver IF amplifier stage is defective
B	One or more of the broadcast stations is transmitting an over-modulated signal
C	You are receiving skywave signals from a distant station
D	Nearby corroded metal joints are mixing and re-radiating the broadcast signals

21. - E5A16

What is the resonant frequency of an RLC circuit if R is 33 ohms, L is 50 microhenries and C is 10 picofarads?

Select	Answer
A	7.12 MHz
B	23.5 MHz
C	7.12 kHz
D	23.5 kHz

22. - E5B09

What is the relationship between the AC current through a capacitor and the voltage across a capacitor?

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

23. - E5C06

What does the impedance 50-j25 represent?

Select	Answer
A	25 ohms resistance in series with 50 ohms capacitive reactance
B	50 ohms resistance in series with 25 ohms inductive reactance
C	25 ohms resistance in series with 50 ohms inductive reactance
D	50 ohms resistance in series with 25 ohms capacitive reactance

24. - E5D01

What is the result of skin effect?

Select	Answer
A	Thermal effects on the surface of the conductor decrease the impedance
B	As frequency increases, RF current flows in a thinner layer of the conductor, closer to the surface
C	As frequency decreases, RF current flows in a thinner layer of the conductor, closer to the surface
D	Thermal effects on the surface of the conductor increase the impedance

25. - E6A09

What is a depletion-mode FET?

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

26. - E6B01

What is the most useful characteristic of a Zener diode?

Select	Answer
A	A negative resistance region
B	A constant current drop under conditions of varying voltage
C	An internal capacitance that varies with the applied voltage
D	A constant voltage drop under conditions of varying current

27. - E6C05

What is an advantage of CMOS logic devices over TTL devices?

Select	Answer
A	Immune to damage from static discharge
B	Differential output capability
C	Lower distortion
D	Lower power consumption

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. - E6E10

What advantage does surface-mount technology offer at RF compared to using through-hole components?

Select	Answer
A	Shorter circuit-board traces
B	Smaller circuit area
C	All these choices are correct
D	Components have less parasitic inductance and capacitance

30. - E6F06

Which of these materials is most commonly used to create photoconductive devices?

Select	Answer
A	A crystalline semiconductor
B	A heavy metal
C	A liquid semiconductor
D	An ordinary metal

31. - E7A11

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

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

32. - E7B11

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

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

33. - E7C05

Which filter type is described as having ripple in the passband and a sharp cutoff?

Select	Answer
A	An active LC filter
B	A passive op-amp filter
C	A Chebyshev filter
D	A Butterworth filter

34. - E7D05

Which of the following types of linear voltage regulator places a constant load on the unregulated voltage source?

Select	Answer
A	A constant current source
B	A series regulator
C	A shunt current source
D	A shunt regulator

35. - E7E10

How does a diode envelope detector function?

Select	Answer
A	By sensing the change of reactance in the diode with respect to frequency
B	By rectification and filtering of RF signals
C	By mixing signals with noise in the transition region of the diode
D	By breakdown of the Zener voltage

36. - E7F01

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

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

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	47
B	24
C	94
D	0.21

38. - E7H08

Which of the following components can be used to reduce thermal drift in crystal oscillators?

Select	Answer
A	NP0 capacitors
B	Non-inductive resistors
C	Toroidal inductors
D	Wirewound resistors

39. - E8A06

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

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

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	0.167
B	0.6
C	60
D	1.67

41. - E8C01

How is Forward Error Correction implemented?

Select	Answer
A	By the receiving station repeating each block of three data characters
B	By transmitting extra data that may be used to detect and correct transmission errors
C	By varying the frequency shift of the transmitted signal according to a predefined algorithm
D	By transmitting a special algorithm to the receiving station along with the data characters

42. - E8D06

What is the advantage of including parity bits in ASCII characters?

Select	Answer
A	Foreign language characters can be sent
B	The signal can overpower interfering signals
C	Faster transmission rate
D	Some types of errors can be detected

43. - E9A13

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

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

44. - E9B08

What is the far field of an antenna?

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

45. - E9C07

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

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

46. - E9D10

What happens to feed-point impedance at the base of a fixed length HF mobile antenna when operated below its resonant frequency?

Select	Answer
A	The radiation resistance increases and the capacitive reactance decreases
B	The radiation resistance decreases and the capacitive reactance increases
C	The radiation resistance decreases and the capacitive reactance decreases
D	The radiation resistance increases and the capacitive reactance increases

47. - E9E01

What system matches a higher-impedance transmission line to a lower-impedance antenna by connecting the line to the driven element in two places spaced a fraction of a wavelength each side of element center?

Select	Answer
A	The omega matching system
B	The gamma matching system
C	The stub matching system
D	The delta matching system

48. - E9F13

What impedance does a 1/4-wavelength transmission line present to a generator when the line is shorted at the far end?

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

49. - E9G10

What do the arcs on a Smith chart represent?

Select	Answer
A	Points with constant reactance
B	SWR
C	Frequency
D	Points with constant resistance

50. - E9H01

When constructing a Beverage antenna, which of the following factors should be included in the design to achieve good performance at the desired frequency?

Select	Answer
A	It should be configured as a four-sided loop
B	Its overall length must not exceed 1/4 wavelength
C	It should be one or more wavelengths long
D	It must be mounted more than 1 wavelength above ground

Figure E7-1