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

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1. - E0A09

Which insulating material commonly used as a thermal conductor for some types of electronic devices is extremely toxic if broken or crushed and the particles are accidentally inhaled?

Select	Answer
A	Beryllium Oxide
B	Mica
C	Zinc oxide
D	Uranium Hexafluoride

2. - E1A07

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

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

3. - E1B03

Within what distance must an amateur station protect an FCC monitoring facility from harmful interference?

Select	Answer
A	3 miles
B	1 mile
C	30 miles
D	10 miles

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

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

7. - E1F11

Which of the following best describes one of the standards that must be met by an external RF power amplifier if it is to qualify for a grant of FCC certification?

Select	Answer
A	It must be capable of external RF switching between its input and output networks
B	It must satisfy the FCC's spurious emission standards when operated at the lesser of 1500 watts or its full output power
C	It must exhibit a gain of 0 dB or less over its full output range
D	It must produce full legal output when driven by not more than 5 watts of mean RF input power

8. - E2A10

What type of satellite appears to stay in one position in the sky?

Select	Answer
A	LEO
B	HEO
C	Geostationary
D	Geomagnetic

9. - E2B03

How is an interlaced scanning pattern generated in a fast-scan (NTSC) television system?

Select	Answer
A	By scanning lines from left to right in one field and right to left in the next
B	By scanning each field from bottom to top
C	By scanning two fields simultaneously
D	By scanning odd numbered lines in one field and even numbered lines in the next

10. - E2C03

From which of the following bands is amateur radio contesting generally excluded?

Select	Answer
A	30 meters
B	6 meters
C	33 centimeters
D	2 meters

11. - E2D09

What type of modulation is used for JT65 contacts?

Select	Answer
A	RTTY
B	PSK
C	Multi-tone AFSK
D	IEEE 802.11

12. - E2E06

What is the most common data rate used for HF packet?

Select	Answer
A	300 baud
B	48 baud
C	1200 baud
D	110 baud

13. - E3A08

When a meteor strikes the Earth's atmosphere, a cylindrical region of free electrons is formed at what layer of the ionosphere?

Select	Answer
A	The E layer
B	The D layer
C	The F2 layer
D	The F1 layer

14. - E3B06

Which of the following amateur bands most frequently provides long-path propagation?

Select	Answer
A	10 meters
B	6 meters
C	80 meters
D	20 meters

15. - E3C01

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

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

16. - E4A03

Which of the following test instruments is used to display spurious signals and/or intermodulation distortion products generated by an SSB transmitter?

Select	Answer
A	A time-domain reflectometer
B	A spectrum analyzer
C	A wattmeter
D	A logic analyzer

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 more power going into the antenna
B	There is possibly a short to ground in the feed line
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	Fewer components in the receiver
B	Easier for front-end circuitry to eliminate image responses
C	Improved receiver noise figure
D	Reduced drift

19. - E4D03

How can intermodulation interference between two repeaters occur?

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

20. - E4E09

What undesirable effect can occur when using an IF noise blanker?

Select	Answer
A	Nearby signals may appear to be excessively wide even if they meet emission standards
B	FM signals can no longer be demodulated
C	Received audio in the speech range might have an echo effect
D	The audio frequency bandwidth of the received signal might be compressed

21. - E5A07

What is the magnitude of the current at the input of a parallel RLC circuit at resonance?

Select	Answer
A	L/R
B	Minimum
C	Maximum
D	R/L

22. - E5B05

What happens to the magnitude of a pure reactance when it is converted to a susceptance?

Select	Answer
A	The sign is reversed
B	It becomes the reciprocal
C	It is unchanged
D	It is shifted by 90 degrees

23. - E5C02

How are impedances described in polar coordinates?

Select	Answer
A	By X and R values
B	By Y and G values
C	By phase angle and magnitude
D	By real and imaginary parts

24. - E5D14

What is reactive power?

Select	Answer
A	Power lost because of capacitor leakage
B	Power consumed in wire resistance in an inductor
C	Wattless, nonproductive power
D	Power consumed in circuit Q

25. - E6A03

Why does a PN-junction diode not conduct current when reverse biased?

Select	Answer
A	Only N-type semiconductor material can conduct current
B	Excess holes in P-type material combine with the electrons in N-type material, converting the entire diode into an insulator
C	Holes in P-type material and electrons in the N-type material are separated by the applied voltage, widening the depletion region
D	Only P-type semiconductor material can conduct current

26. - E6B07

What is the failure mechanism when a junction diode fails due to excessive current?

Select	Answer
A	Excessive junction temperature
B	Charge carrier depletion
C	Excessive inverse voltage
D	Insufficient forward voltage

27. - E6C08

In Figure E6-3, what is the schematic symbol for a NAND gate?

Select	Answer
A	2
B	1
C	3
D	4

28. - E6D06

What core material property determines the inductance of an inductor?

Select	Answer
A	Thermal impedance
B	Permeability
C	Reactivity
D	Resistance

29. - E6E09

Which of the following component package types would be most suitable for use at frequencies above the HF range?

Select	Answer
A	Axial lead
B	Surface mount
C	TO-220
D	Radial lead

30. - E6F05

Which describes an optical shaft encoder?

Select	Answer
A	A device that measures the strength of a beam of light using analog to digital conversion
B	A digital encryption device often used to encrypt spacecraft control signals
C	A device that detects rotation of a control by interrupting a light source with a patterned wheel
D	A device for generating RTTY signals by means of a rotating light source

31. - E7A04

How many flip-flops are required to divide a signal frequency by 4?

Select	Answer
A	4
B	1
C	2
D	8

32. - E7B18

What is a characteristic of a grounded-grid amplifier?

Select	Answer
A	Low input impedance
B	Low bandwidth
C	High filament voltage
D	High power gain

33. - E7C12

What is one advantage of a Pi-matching network over an L-matching network consisting of a single inductor and a single capacitor?

Select	Answer
A	Pi-networks are more stable
B	Pi-networks provide balanced input and output
C	L-networks cannot perform impedance transformation
D	The Q of Pi-networks can be controlled

34. - E7D04

Which of the following types of linear voltage regulator usually make the most efficient use of the primary power source?

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

35. - E7E08

What are the principal frequencies that appear at the output of a mixer circuit?

Select	Answer
A	1.414 and 0.707 times the input frequency
B	The square root of the product of input frequencies
C	Two and four times the original frequency
D	The two input frequencies along with their sum and difference frequencies

36. - E7F04

What is a common method of generating an SSB signal using digital signal processing?

Select	Answer
A	Varying quartz crystal characteristics emulated in digital form
B	Mixing products are converted to voltages and subtracted by adder circuits
C	A frequency synthesizer removes the unwanted sidebands
D	Signals are combined in quadrature phase relationship

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. - E7H06

Which of the following oscillator circuits are commonly used in VFOs?

Select	Answer
A	Pierce and Zener
B	Armstrong and deForest
C	Negative feedback and balanced feedback
D	Colpitts and Hartley

39. - E8A02

Which of the following is a type of analog-to-digital conversion?

Select	Answer
A	Successive approximation
B	Harmonic regeneration
C	Level shifting
D	Phase reversal

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. - E8C05

What is the approximate bandwidth of a 13-WPM International Morse Code transmission?

Select	Answer
A	13 Hz
B	104 Hz
C	26 Hz
D	52 Hz

42. - E8D07

What is a common cause of overmodulation of AFSK signals?

Select	Answer
A	Excessive transmit audio levels
B	Ground loops
C	Bit errors in the modem
D	Excessive numbers of retries

43. - E9A06

What is the effective radiated power relative to a dipole of a repeater station with 200 watts transmitter power output, 4 dB feed line loss, 3.2 dB duplexer loss, 0.8 dB circulator loss, and 10 dBd antenna gain?

Select	Answer
A	2000 watts
B	317 watts
C	126 watts
D	300 watts

44. - E9B07

How does the total amount of radiation emitted by a directional gain antenna compare with the total amount of radiation emitted from a theoretical isotropic antenna, assuming each is driven by the same amount of power?

Select	Answer
A	The radiation from the isotropic antenna is 2.15 dB stronger than that from the directional antenna
B	The total amount of radiation from the directional antenna is stronger by its front-to-back ratio
C	They are the same
D	The total amount of radiation from the directional antenna is increased by the gain of the antenna

45. - E9C09

Which of the following describes a G5RV antenna?

Select	Answer
A	A wide band dipole using shorted coaxial cable for the radiating elements and fed with a�4:1 balun
B	A multi-band dipole antenna fed with coax and a balun through a selected length of open wire transmission line
C	A phased array antenna consisting of multiple loops
D	A multi-band trap antenna

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	At a voltage node
C	Near the center of the vertical radiator
D	As low as possible on the vertical radiator

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	75 ohms
B	50 ohms
C	62 ohms
D	450 ohms

48. - E9F12

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

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

49. - E9G11

How are the wavelength scales on a Smith chart calibrated?

Select	Answer
A	In fractions of antenna electrical frequency
B	In fractions of transmission line electrical wavelength
C	In fractions of antenna electrical wavelength
D	In fractions of transmission line electrical frequency

50. - E9H04

What is an advantage of placing a grounded electrostatic shield around a small loop direction-finding antenna?

Select	Answer
A	It adds capacitive loading, increasing the bandwidth of the antenna
B	It increases signal strength by providing a better match to the feed line
C	It eliminates unbalanced capacitive coupling to the surroundings, improving the nulls
D	It eliminates tracking errors caused by strong out-of-band signals

Figure E6-3