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. - E0A08

What does SAR measure?

Select	Answer
A	The rate of RF energy reflected from stationary terrain
B	Signal Amplification Rating
C	Synthetic Aperture Ratio of the human body
D	The rate at which RF energy is absorbed by the body

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. - E1B02

Which of the following is an acceptable bandwidth for Digital Radio Mondiale (DRM) based voice or SSTV digital transmissions made on the HF amateur bands?

Select	Answer
A	15 kHz
B	20 kHz
C	3 kHz
D	10 kHz

4. - E1C02

Which of the following types of communications may be transmitted to amateur stations in foreign countries?

Select	Answer
A	Communications incidental to the purpose of the amateur service and remarks of a personal nature
B	All these choices are correct
C	Business-related messages for non-profit organizations
D	Messages intended for users of the maritime satellite service

5. - E1D07

Which HF amateur bands have frequencies authorized for space stations?

Select	Answer
A	Only the 40, 20, 17, 15, and 10 meter bands
B	All HF bands
C	Only the 40, 30, 20, 15, 12, and 10 meter bands
D	Only the 40, 20, 17, 15, 12, and 10 meter bands

6. - E1E11

What must the VE team do if an examinee scores a passing grade on all examination elements needed for an upgrade or new license?

Select	Answer
A	Three VEs must certify that the examinee is qualified for the license grant and that they have complied with the administering VE requirements
B	Photocopy all examination documents and forward them to the FCC for processing
C	All these choices are correct
D	Issue the examinee the new or upgrade license

7. - E1F08

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

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

8. - E2A01

What is the direction of an ascending pass for an amateur satellite?

Select	Answer
A	From west to east
B	From north to south
C	From east to west
D	From south to north

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

10. - E2C04

Which of the following frequencies are sometimes used for amateur radio mesh networks?

Select	Answer
A	HF frequencies where digital communications are permitted
B	Cable TV channels 41 through 43
C	Frequencies shared with various unlicensed wireless data services
D	The 60 meter band channel centered on 5373 kHz

11. - E2D11

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

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

12. - E2E06

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

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

13. - E3A10

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

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

14. - E3B03

What is the best time of day for transequatorial propagation?

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

15. - E3C01

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

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

16. - E4A08

Which of the following measures SWR?

Select	Answer
A	A spectrum analyzer
B	A Q meter
C	An ohmmeter
D	An antenna analyzer

17. - E4B03

Which S parameter is equivalent to forward gain?

Select	Answer
A	S22
B	S12
C	S11
D	S21

18. - E4C02

Which of the following receiver circuits can be effective in eliminating interference from strong out-of-band signals?

Select	Answer
A	A properly adjusted product detector
B	A narrow IF filter
C	A notch filter
D	A front-end filter or pre-selector

19. - E4D08

What causes intermodulation in an electronic circuit?

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

20. - E4E07

Which of the following can cause shielded cables to radiate or receive interference?

Select	Answer
A	Low inductance ground connections at both ends of the shield
B	Common-mode currents on the shield and conductors
C	Use of braided shielding material
D	Tying all ground connections to a common point resulting in differential-mode currents in the shield

21. - E5A11

What is the half-power bandwidth of a resonant circuit that has a resonant frequency of 7.1 MHz and a Q of 150?

Select	Answer
A	23.67 kHz
B	157.8 Hz
C	47.3 kHz
D	315.6 Hz

22. - E5B05

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

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

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

24. - E5D05

What is the power factor of an RL circuit having a 30-degree phase angle between the voltage and the current?

Select	Answer
A	0.866
B	0.577
C	0.5
D	1.73

25. - E6A12

Why do many MOSFET devices have internally connected Zener diodes on the gates?

Select	Answer
A	To reduce the chance of static damage to the gate
B	To keep the gate voltage within specifications and prevent the device from overheating
C	To protect the substrate from excessive voltages
D	To provide a voltage reference for the correct amount of reverse-bias gate voltage

26. - E6B03

What type of bias is required for an LED to emit light?

Select	Answer
A	Inductive bias
B	Forward bias
C	Zero bias
D	Reverse bias

27. - E6C05

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

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

28. - E6D05

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

Select	Answer
A	Ferrite toroids generally require fewer turns to produce a given inductance value
B	Ferrite toroids generally have lower initial permeability
C	Ferrite toroids generally have better temperature stability
D	Ferrite toroids are easier to use with surface mount technology

29. - E6E02

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

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

30. - E6F06

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

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

31. - E7A10

What is a truth table?

Select	Answer
A	A table of logic symbols that indicate the logic states of an op-amp
B	A table of logic symbols that indicate the high logic states of an op-amp
C	A diagram showing logic states when the digital device output is true
D	A list of inputs and corresponding outputs for a digital device

32. - E7B13

Which of the following describes an emitter follower (or common collector) amplifier?

Select	Answer
A	A two-transistor amplifier with the emitters sharing a common bias resistor
B	A differential amplifier with both inputs fed to the emitter of the input transistor
C	An OR circuit with only one emitter used for output
D	An amplifier with a low impedance output that follows the base input voltage

33. - E7C08

Which of the following factors has the greatest effect on the bandwidth and response shape of a crystal ladder filter?

Select	Answer
A	The amplitude of the signals passing through the filter
B	The gain of the RF stage preceding the filter
C	The DC voltage applied to the quartz crystal
D	The relative frequencies of the individual crystals

34. - E7D14

What is the purpose of connecting equal-value resistors across power supply filter capacitors connected in series?

Select	Answer
A	All these choices are correct
B	Equalize the voltage across each capacitor
C	Provide a minimum load on the supply
D	Discharge the capacitors when voltage is removed

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 breakdown of the Zener voltage
D	By mixing signals with noise in the transition region of the diode

36. - E7F02

What kind of digital signal processing audio filter is used to remove unwanted noise from a received SSB signal?

Select	Answer
A	A Hilbert-transform filter
B	A crystal-lattice filter
C	An adaptive filter
D	A phase-inverting filter

37. - E7G03

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

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

38. - E7H05

How is positive feedback supplied in a Pierce oscillator?

Select	Answer
A	Through a quartz crystal
B	Through a neutralizing capacitor
C	Through link coupling
D	Through a tapped coil

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

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	1/3
B	2000
C	3
D	6000

41. - E8C02

What is the definition of symbol rate in a digital transmission?

Select	Answer
A	The duration of each bit in a message sent over the air
B	The number of characters carried per second by the station-to-station link
C	The number of control characters in a message packet
D	The rate at which the waveform changes to convey information

42. - E8D10

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

Select	Answer
A	Baudot uses 7 data bits per character, ASCII uses 8; Baudot has no letters/figures shift code, ASCII uses 2 letters/figures shift codes
B	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
C	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
D	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

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	632 watts
B	63.2 watts
C	159 watts
D	252 watts

44. - E9B10

What is the principle of a Method of Moments analysis?

Select	Answer
A	A wire is modeled as a single sine-wave current generator
B	A wire is modeled as a series of segments, each having a distinct value of voltage across it
C	A wire is modeled as a series of segments, each having a uniform value of current
D	A wire is modeled as a single sine-wave voltage source

45. - E9C11

How is the far-field elevation pattern of a vertically polarized antenna affected by being mounted over seawater versus soil?

Select	Answer
A	Additional higher vertical angle lobes will appear
B	The low-angle radiation decreases
C	The low-angle radiation increases
D	Fewer vertical angle lobes will be present

46. - E9D06

What happens to the SWR bandwidth when one or more loading coils are used to resonate an electrically short antenna?

Select	Answer
A	It is increased
B	It is unchanged if the loading coil is located at a voltage maximum point
C	It is decreased
D	It is unchanged if the loading coil is located at the feed point

47. - E9E11

What is the primary purpose of phasing lines when used with an antenna having multiple driven elements?

Select	Answer
A	It allows single-band antennas to operate on other bands
B	It ensures that each driven element operates in concert with the others to create the desired antenna pattern
C	It prevents reflected power from traveling back down the feed line and causing harmonic radiation from the transmitter
D	It creates a low-angle radiation pattern

48. - E9F05

What is the approximate physical length of a solid polyethylene dielectric coaxial transmission line that is electrically 1/4 wavelength long at 14.1 MHz?

Select	Answer
A	10.6 meters
B	4.3 meters
C	5.3 meters
D	3.5 meters

49. - E9G09

What third family of circles is often added to a Smith chart during the process of solving problems?

Select	Answer
A	Antenna-length circles
B	Standing wave ratio circles
C	Coaxial-length circles
D	Radiation-pattern circles

50. - E9H03

What is Receiving Directivity Factor (RDF)?

Select	Answer
A	Relative directivity compared to isotropic
B	Forward gain compared to average gain over the entire hemisphere
C	Relative directivity compared to a dipole
D	Forward gain compared to the gain in the reverse direction