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

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1. - E0A08

What does SAR measure?

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

2. - E1A03

What is the maximum legal carrier frequency on the 20 meter band for transmitting USB AFSK digital signals having a 1 kHz bandwidth?

Select	Answer
A	14.100 MHz
B	14.070 MHz
C	14.349 MHz
D	14.149 MHz

3. - E1B08

What limitations may the FCC place on an amateur station if its signal causes interference to domestic broadcast reception, assuming that the receivers involved are of good engineering design?

Select	Answer
A	The amateur station must avoid transmitting during certain hours on frequencies that cause the interference
B	The amateur station must cease operation on all frequencies above 30 MHz
C	The amateur station must cease operation on all frequencies below 30 MHz
D	The amateur station must cease operation

4. - E1C06

Which of the following is required in order to operate in accordance with CEPT rules in foreign countries where permitted?

Select	Answer
A	The U.S. embassy must approve of your operation
B	You must identify in the official language of the country in which you are operating
C	You must append "/CEPT" to your call sign
D	You must bring a copy of FCC Public Notice DA 16-1048

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 that transmits communications to initiate, modify or terminate functions of a space station
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 located in a satellite or a balloon more than 50 kilometers above the surface of the Earth

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

7. - E1F03

Under what circumstances may a dealer sell an external RF power amplifier capable of operation below 144 MHz if it has not been granted FCC certification?

Select	Answer
A	It was purchased in used condition from an amateur operator and is sold to another amateur operator for use at that operator's station
B	It was imported from a manufacturer in another country and was certificated by that country's government
C	The equipment dealer assembled it from a kit
D	It was imported from a manufacturer in a country that does not require certification of RF power amplifiers

8. - E2A07

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

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

9. - E2B03

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

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

10. - E2C03

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

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

11. - E2D04

What technology is used to track, in real time, balloons carrying amateur radio transmitters?

Select	Answer
A	APRS
B	Ultrasonics
C	Bandwidth compressed LORAN
D	Doppler shift of beacon signals

12. - E2E07

Which of the following is a possible reason that attempts to initiate contact with a digital station on a clear frequency are unsuccessful?

Select	Answer
A	Your transmit frequency is incorrect
B	The protocol version you are using is not supported by the digital station
C	All these choices are correct
D	Another station you are unable to hear is using the frequency

13. - E3A09

Which of the following frequency ranges is most suited for meteor scatter communications?

Select	Answer
A	28 MHz - 148 MHz
B	1.8 MHz - 1.9 MHz
C	220 MHz - 450 MHz
D	10 MHz - 14 MHz

14. - E3B06

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

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

15. - E3C01

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

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

16. - E4A02

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

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

17. - E4B03

Which S parameter is equivalent to forward gain?

Select	Answer
A	S22
B	S11
C	S12
D	S21

18. - E4C06

A CW receiver with the AGC off has an equivalent input noise power density of -174 dBm/Hz. What would be the level of an unmodulated carrier input to this receiver that would yield an audio output SNR of 0 dB in a 400 Hz noise bandwidth?

Select	Answer
A	-155 dBm
B	-148 dBm
C	-174 dBm
D	-164 dBm

19. - E4D10

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

Select	Answer
A	The receiver can tolerate signals up to 40 dB above the noise floor without producing third-order intermodulation products
B	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
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	Signals less than 40 dBm will not generate audible third-order intermodulation products

20. - E4E01

What problem can occur when using an automatic notch filter (ANF) to remove interfering carriers while receiving CW signals?

Select	Answer
A	Removal of the CW signal as well as the interfering carrier
B	Any nearby signal passing through the DSP system will overwhelm the desired signal
C	Received CW signals will appear to be modulated at the DSP clock frequency
D	Ringing in the DSP filter will completely remove the spaces between the CW characters

21. - E5A13

What is an effect of increasing Q in a series resonant circuit?

Select	Answer
A	Fewer components are needed for the same performance
B	Internal voltages increase
C	Parasitic effects are minimized
D	Phase shift can become uncontrolled

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

23. - E5C08

What coordinate system is often used to display the phase angle of a circuit containing resistance, inductive and/or capacitive reactance?

Select	Answer
A	Elliptical coordinates
B	Maidenhead grid
C	Faraday grid
D	Polar coordinates

24. - E5D11

What is the power factor of an RL circuit having a 60-degree phase angle between the voltage and the current?

Select	Answer
A	1.414
B	0.5
C	1.73
D	0.866

25. - E6A11

In Figure E6-1, what is the schematic symbol for a P-channel junction FET?

Select	Answer
A	2
B	3
C	1
D	6

26. - E6B09

What is a common use for point-contact diodes?

Select	Answer
A	As an RF detector
B	As a high-voltage rectifier
C	As a constant voltage source
D	As a constant current source

27. - E6C09

What is a Programmable Logic Device (PLD)?

Select	Answer
A	A type of transistor whose gain can be changed by digital logic circuits
B	A logic circuit that can be modified during use
C	Programmable equipment used for testing digital logic integrated circuits
D	A programmable collection of logic gates and circuits in a single integrated circuit

28. - E6D10

What is a primary advantage of using a toroidal core instead of a solenoidal core in an inductor?

Select	Answer
A	Toroidal cores exhibit greater hysteresis
B	Toroidal cores have lower Q characteristics
C	Toroidal cores confine most of the magnetic field within the core material
D	Toroidal cores make it easier to couple the magnetic energy into other components

29. - E6E10

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

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

30. - E6F05

Which describes an optical shaft encoder?

Select	Answer
A	A device for generating RTTY signals by means of a rotating light source
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 that measures the strength of a beam of light using analog to digital conversion

31. - E7A09

What logical operation is performed by an exclusive NOR gate?

Select	Answer
A	It produces logic 1 at its output only if all inputs are logic 1
B	It produces logic 0 at its output if only one input is logic 1
C	It produces logic 1 at its output if only one input is logic 1
D	It produces logic 0 at its output only if all inputs are logic 0

32. - E7B01

For what portion of the signal cycle does each active element in a push-pull Class AB amplifier conduct?

Select	Answer
A	Exactly 180 degrees
B	More than 180 degrees but less than 360 degrees
C	Less than 180 degrees
D	The entire cycle

33. - E7C04

How does an impedance-matching circuit transform a complex impedance to a resistive impedance?

Select	Answer
A	It introduces transconductance to cancel the reactive part of impedance
B	Reactive currents are dissipated in matched resistances
C	It introduces negative resistance to cancel the resistive part of impedance
D	It cancels the reactive part of the impedance and changes the resistive part to a desired value

34. - E7D09

What is the main reason to use a charge controller with a solar power system?

Select	Answer
A	Prevention of battery undercharge
B	Control of electrolyte levels during battery discharge
C	Prevention of battery damage due to overcharge
D	Matching of day and night charge rates

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	Two and four times the original frequency
C	The square root of the product of input frequencies
D	The two input frequencies along with their sum and difference frequencies

36. - E7F14

Which of the following would allow a digital signal processing filter to create a sharper filter response?

Select	Answer
A	Double-precision math routines
B	Higher data rate
C	Complex phasor representations
D	More taps

37. - E7G10

What absolute voltage gain can be expected from the circuit in Figure E7-3 when R1 is 1800 ohms and RF is 68 kilohms?

Select	Answer
A	38
B	76
C	0.03
D	1

38. - E7H14

What is a phase-locked loop circuit?

Select	Answer
A	An electronic servo loop consisting of a phase detector, a low-pass filter, a voltage-controlled oscillator, and a stable reference oscillator
B	An electronic circuit consisting of a precision push-pull amplifier with a differential input
C	An electronic servo loop consisting of a ratio detector, reactance modulator, and voltage-controlled oscillator
D	An electronic circuit also known as a monostable multivibrator

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. - E8B10

What is frequency division multiplexing?

Select	Answer
A	Two or more information streams are merged into a baseband, which then modulates the transmitter
B	Two or more information streams are merged into a digital combiner, which then pulse position modulates the transmitter
C	The transmitted signal jumps from band to band at a predetermined rate
D	The transmitted signal is divided into packets of information

41. - E8C01

How is Forward Error Correction implemented?

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

42. - E8D10

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

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

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	126 watts
B	300 watts
C	317 watts
D	2000 watts

44. - E9B02

In the antenna radiation pattern shown in Figure E9-1, what is the front-to-back ratio?

Select	Answer
A	36 dB
B	14 dB
C	24 dB
D	18 dB

45. - E9C12

Which of the following describes an Extended Double Zepp antenna?

Select	Answer
A	An end-fed folded dipole antenna
B	A center-fed 1.25-wavelength antenna (two 5/8-wave elements in phase)
C	A wideband vertical antenna constructed from precisely tapered aluminum tubing
D	A portable antenna erected using two push support poles

46. - E9D08

What happens as the Q of an antenna increases?

Select	Answer
A	SWR bandwidth increases
B	More common-mode current is present on the feed line
C	Gain is reduced
D	SWR bandwidth decreases

47. - E9E09

Which of the following is used to shunt-feed a grounded tower at its base?

Select	Answer
A	Double-bazooka match
B	Hairpin match
C	Gamma match
D	All these choices are correct

48. - E9F07

How does ladder line compare to small-diameter coaxial cable such as RG-58 at 50 MHz?

Select	Answer
A	Smaller reflection coefficient
B	Lower loss
C	Higher SWR
D	Lower velocity factor

49. - E9G09

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

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

50. - E9H11

What feature of a cardioid pattern antenna makes it useful for direction finding?

Select	Answer
A	High radiation angle
B	Broadband response
C	A very sharp single null
D	A very sharp peak

Figure E6-1

Figure E7-3

Figure E9-1