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	Uranium Hexafluoride
C	Zinc oxide
D	Mica

2. - E1A04

With your transceiver displaying the carrier frequency of phone signals, you hear a DX station calling CQ on 3.601 MHz LSB. Is it legal to return the call using lower sideband on the same frequency?

Select	Answer
A	Yes, because the DX station initiated the contact
B	No, the sideband will extend beyond the edge of the phone band segment
C	Yes, because the displayed frequency is within the 75 meter phone band segment
D	No, U.S. stations are not permitted to use phone emissions below 3.610 MHz

3. - E1B07

To what type of regulations does PRB-1 apply?

Select	Answer
A	FAA tower height limits
B	Use of wireless devices in vehicles
C	Homeowners associations
D	State and local zoning

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

5. - E1D06

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

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

6. - E1E01

For which types of out-of-pocket expenses do the Part 97 rules state that VEs and VECs may be reimbursed?

Select	Answer
A	No expenses are authorized for reimbursement
B	Teaching an amateur operator license examination preparation course
C	Preparing, processing, administering, and coordinating an examination for an amateur radio operator license
D	Providing amateur operator license examination preparation training materials

7. - E1F10

Who may be the control operator of an auxiliary station?

Select	Answer
A	Only Amateur Extra Class operators
B	Only Technician, General, Advanced or Amateur Extra Class operators
C	Only General, Advanced or Amateur Extra Class operators
D	Any licensed amateur operator

8. - E2A02

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

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

9. - E2B04

How is color information sent in analog SSTV?

Select	Answer
A	Color is sent in a color burst at the end of each line
B	Color is amplitude modulated on the frequency modulated intensity signal
C	Color lines are sent sequentially
D	Color information is sent on a 2.8 kHz subcarrier

10. - E2C07

What is the Cabrillo format?

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

11. - E2D11

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

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

12. - E2E05

Which of these digital modes does not support keyboard-to-keyboard operation?

Select	Answer
A	PSK31
B	RTTY
C	MFSK
D	PACTOR

13. - E3A01

What is the approximate maximum separation measured along the surface of the Earth between two stations communicating by EME?

Select	Answer
A	5000 miles, if the moon is at perigee
B	500 miles, if the moon is at perigee
C	2000 miles, if the moon is at apogee
D	12,000 miles, if the moon is visible by both stations

14. - E3B05

Which amateur bands typically support long-path propagation?

Select	Answer
A	Only 30 meters to 10 meters
B	6 meters to 2 meters
C	160 meters to 10 meters
D	Only 160 meters to 40 meters

15. - E3C13

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

Select	Answer
A	Horizontal
B	Circular
C	Vertical
D	Elliptical

16. - E4A08

Which of the following measures SWR?

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

17. - E4B03

Which S parameter is equivalent to forward gain?

Select	Answer
A	S22
B	S12
C	S11
D	S21

18. - E4C01

What is an effect of excessive phase noise in a receiver's local oscillator?

Select	Answer
A	It limits the receiver's ability to receive strong signals
B	It decreases receiver third-order intercept point
C	It can affect the receiver's frequency calibration
D	It can combine with strong signals on nearby frequencies to generate interference

19. - E4D10

What does a third-order intercept level of 40 dBm mean with respect to receiver performance?

Select	Answer
A	Signals less than 40 dBm will not generate audible third-order intermodulation products
B	The receiver can tolerate signals up to 40 dB above the noise floor without producing third-order intermodulation products
C	A pair of 1 mW input signals will produce a third-order intermodulation product that is 40 dB stronger than the input signal
D	A pair of 40 dBm input signals will theoretically generate a third-order intermodulation product that has the same output amplitude as either of the input signals

20. - E4E08

What current flows equally on all conductors of an unshielded multi-conductor cable?

Select	Answer
A	Reactive current only
B	Common-mode current
C	Differential-mode current
D	Return current

21. - E5A07

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

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

22. - E5B11

What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 25 ohms, R is 100 ohms, and XL is 50 ohms?

Select	Answer
A	76 degrees with the voltage lagging the current
B	14 degrees with the voltage leading the current
C	14 degrees with the voltage lagging the current
D	76 degrees with the voltage leading the current

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

24. - E5D13

How many watts are consumed in a circuit consisting of a 100-ohm resistor in series with a 100-ohm inductive reactance drawing 1 ampere?

Select	Answer
A	70.7 watts
B	200 watts
C	141.4 watts
D	100 watts

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 protect the substrate from excessive voltages
C	To keep the gate voltage within specifications and prevent the device from overheating
D	To provide a voltage reference for the correct amount of reverse-bias gate voltage

26. - E6B04

What type of semiconductor device is designed for use as a voltage-controlled capacitor?

Select	Answer
A	Zener diode
B	Silicon-controlled rectifier
C	Varactor diode
D	Tunnel diode

27. - E6C10

In Figure E6-3, what is the schematic symbol for a NOR gate?

Select	Answer
A	2
B	4
C	1
D	3

28. - E6D05

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

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

29. - E6E05

Which of the following noise figure values is typical of a low-noise UHF preamplifier?

Select	Answer
A	2 dB
B	-10 dB
C	-20 dBm
D	44 dBm

30. - E6F10

What is the most common type of photovoltaic cell used for electrical power generation?

Select	Answer
A	Silicon
B	Selenium
C	Copper oxide
D	Cadmium Sulfide

31. - E7A02

What is the function of a decade counter?

Select	Answer
A	It produces one output pulse for every 10 input pulses
B	It decodes a decimal number for display on a seven-segment LED display
C	It decodes a binary number for display on a seven-segment LED display
D	It produces 10 output pulses for every input pulse

32. - E7B07

Which of the following is a likely result when a Class C amplifier is used to amplify a single-sideband phone signal?

Select	Answer
A	Increased overall intelligibility
B	Signal distortion and excessive bandwidth
C	Reduced intermodulation products
D	Signal inversion

33. - E7C07

Which describes a Pi-L-network used for matching a vacuum tube final amplifier to a 50-ohm unbalanced output?

Select	Answer
A	A Phase Inverter Load network
B	A matching network in which all components are isolated from ground
C	A Pi-network with an additional series inductor on the output
D	A network with only three discrete parts

34. - E7D15

What is the purpose of a step-start circuit in a high-voltage power supply?

Select	Answer
A	To provide a dual-voltage output for reduced power applications
B	To allow for remote control of the power supply
C	To compensate for variations of the incoming line voltage
D	To allow the filter capacitors to charge gradually

35. - E7E09

What occurs when an excessive amount of signal energy reaches a mixer circuit?

Select	Answer
A	Automatic limiting occurs
B	Mixer blanking occurs
C	A beat frequency is generated
D	Spurious mixer products are generated

36. - E7F11

What sets the minimum detectable signal level for a direct-sampling SDR receiver in the absence of atmospheric or thermal noise?

Select	Answer
A	Reference voltage level and sample width in bits
B	Missing codes and jitter
C	Sample clock phase noise
D	Data storage transfer rate

37. - E7G03

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

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

38. - E7H03

How is positive feedback supplied in a Hartley oscillator?

Select	Answer
A	Through a tapped coil
B	Through link coupling
C	Through a neutralizing capacitor
D	Through a capacitive divider

39. - E8A03

What type of wave does a Fourier analysis show to be made up of sine waves of a given fundamental frequency plus all its harmonics?

Select	Answer
A	A sawtooth wave
B	A cosine wave
C	A sine wave
D	A square wave

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	1.67
B	60
C	0.6
D	0.167

41. - E8C07

What is the bandwidth of a 4800-Hz frequency shift, 9600-baud ASCII FM transmission?

Select	Answer
A	9.6 kHz
B	5.76 kHz
C	4.8 kHz
D	15.36 kHz

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 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 7 data bits per character, ASCII uses 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. - E9A11

Which of the following factors determines ground losses for a ground-mounted vertical antenna operating in the 3 MHz to 30 MHz range?

Select	Answer
A	Take-off angle
B	Soil conductivity
C	Distance from the transmitter
D	The standing wave ratio

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

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	A figure-8 broadside to the axis of the array
C	Cardioid
D	A figure-8 end-fire along 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 minimize the Q
B	To lower the radiation angle
C	To swamp out harmonics
D	To minimize losses

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 delta matching system
B	The stub matching system
C	The gamma matching system
D	The omega matching system

48. - E9F01

What is the velocity factor of a transmission line?

Select	Answer
A	The velocity of the wave in the transmission line multiplied by the velocity of light in a vacuum
B	The index of shielding for coaxial cable
C	The ratio of the characteristic impedance of the line to the terminating impedance
D	The velocity of the wave in the transmission line divided by the velocity of light in a vacuum

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. - E9H09

What is a Pennant antenna?

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

Figure E6-3