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. - 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	Zinc oxide
B	Mica
C	Beryllium Oxide
D	Uranium Hexafluoride

2. - E1A06

Where must the carrier frequency of a CW signal be set to comply with FCC rules for 60 meter operation?

Select	Answer
A	At the highest frequency of the channel
B	At the lowest frequency of the channel
C	At the center frequency of the channel
D	On any frequency where the signal's sidebands are within the channel

3. - E1B06

Which of the following additional rules apply if you are installing an amateur station antenna at a site at or near a public use airport?

Select	Answer
A	You must file an Environmental Impact Statement with the EPA before construction begins
B	You must submit engineering drawings to the FAA
C	You must obtain a construction permit from the airport zoning authority
D	You may have to notify the Federal Aviation Administration and register it with the FCC as required by Part 17 of the FCC rules

4. - E1C03

How do the control operator responsibilities of a station under automatic control differ from one under local control?

Select	Answer
A	Under automatic control there is no control operator
B	Under local control there is no control operator
C	Under automatic control the control operator is not required to be present at the control point
D	Under local control a control operator is not required to be present at a control point

5. - E1D03

What is a space telecommand station?

Select	Answer
A	An amateur station that transmits communications to initiate, modify or terminate functions of a space station
B	An amateur station located on the surface of the Earth for communication with other Earth stations by means of Earth satellites
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. - E1E08

To which of the following examinees may a VE not administer an examination?

Select	Answer
A	Friends of the VE
B	Relatives of the VE as listed in the FCC rules
C	All these choices are correct
D	Employees of the VE

7. - E1F02

What privileges are authorized in the U.S. to persons holding an amateur service license granted by the government of Canada?

Select	Answer
A	All privileges of the Amateur Extra Class license
B	The operating terms and conditions of the Canadian amateur service license, not to exceed U.S. Amateur Extra Class license privileges
C	Full privileges, up to and including those of the Amateur Extra Class license, on the 80, 40, 20, 15, and 10 meter bands
D	None, they must obtain a U.S. license

8. - E2A02

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

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

9. - E2B11

What is the function of the Vertical Interval Signaling (VIS) code sent as part of an SSTV transmission?

Select	Answer
A	To identify the call sign of the station transmitting
B	To identify the SSTV mode being used
C	To lock the color burst oscillator in color SSTV images
D	To provide vertical synchronization

10. - E2C10

Why might a DX station state that they are listening on another frequency?

Select	Answer
A	To separate the calling stations from the DX station
B	All these choices are correct
C	Because the DX station may be transmitting on a frequency that is prohibited to some responding stations
D	To improve operating efficiency by reducing interference

11. - E2D08

What type of packet frame is used to transmit APRS beacon data?

Select	Answer
A	Acknowledgement
B	Connect
C	Unnumbered Information
D	Disconnect

12. - E2E02

What do the letters FEC mean as they relate to digital operation?

Select	Answer
A	Fatal Error Correction
B	Forward Error Correction
C	First Error Correction
D	Final Error Correction

13. - E3A01

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

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

14. - E3B01

What is transequatorial propagation?

Select	Answer
A	Propagation between two mid-latitude points at approximately the same distance north and south of the magnetic equator
B	Propagation between a point on the equator and its antipodal point
C	Propagation between points at the same latitude
D	Propagation between points located on the magnetic equator

15. - E3C03

Which of the following signal paths is most likely to experience high levels of absorption when the A index or K index is elevated?

Select	Answer
A	Transequatorial
B	Sporadic E
C	Polar
D	NVIS

16. - E4A05

What is the purpose of the prescaler function on a frequency counter?

Select	Answer
A	It amplifies low-level signals for more accurate counting
B	It multiplies a higher frequency signal so a low-frequency counter can display the operating frequency
C	It divides a higher frequency signal so a low-frequency counter can display the input frequency
D	It prevents oscillation in a low-frequency counter circuit

17. - E4B01

Which of the following factors most affects the accuracy of a frequency counter?

Select	Answer
A	Time base accuracy
B	Input attenuator accuracy
C	Temperature coefficient of the logic
D	Decade divider accuracy

18. - E4C15

What is reciprocal mixing?

Select	Answer
A	Local oscillator phase noise mixing with adjacent strong signals to create interference to desired signals
B	Two digital signals combining from alternate time slots
C	In-phase signals cancelling in a mixer resulting in loss of receiver sensitivity
D	Two out-of-band signals mixing to generate an in-band spurious signal

19. - E4D11

Why are odd-order intermodulation products, created within a receiver, of particular interest compared to other products?

Select	Answer
A	Odd-order intermodulation produces three products for every input signal within the band of interest
B	Odd-order products of two signals in the band of interest are also likely to be within the band
C	Odd-order products are an indication of poor image rejection
D	Odd-order products overload the IF filters

20. - E4E06

What is one type of electrical interference that might be caused by a nearby personal computer?

Select	Answer
A	A clicking noise at intervals of a few seconds
B	A loud AC hum in the audio output of your station receiver
C	The appearance of unstable modulated or unmodulated signals at specific frequencies
D	A whining type noise that continually pulses off and on

21. - E5A06

What is the magnitude of the circulating current within the components of a parallel LC circuit at resonance?

Select	Answer
A	It is at a minimum
B	It is at a maximum
C	It equals 2 multiplied by pi, multiplied by frequency, multiplied by inductance
D	It equals 1 divided by the quantity 2 times pi, multiplied by the square root of inductance L multiplied by capacitance C

22. - E5B08

What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 100 ohms, R is 100 ohms, and XL is 75 ohms?

Select	Answer
A	76 degrees with the voltage leading 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 lagging the current

23. - E5C11

Which point in Figure E5-1 best represents the impedance of a series circuit consisting of a 300-ohm resistor and an 18-microhenry inductor at 3.505 MHz?

Select	Answer
A	Point 3
B	Point 1
C	Point 7
D	Point 8

24. - E5D04

Why are short connections used at microwave frequencies?

Select	Answer
A	To increase neutralizing resistance
B	To reduce phase shift along the connection
C	To increase compensating capacitance
D	To reduce noise figure

25. - E6A01

In what application is gallium arsenide used as a semiconductor material?

Select	Answer
A	In high-power audio circuits
B	In very low-frequency RF circuits
C	In high-current rectifier circuits
D	In microwave circuits

26. - E6B02

What is an important characteristic of a Schottky diode as compared to an ordinary silicon diode when used as a power supply rectifier?

Select	Answer
A	Much higher reverse voltage breakdown
B	Less forward voltage drop
C	Longer carrier retention time
D	More constant reverse avalanche voltage

27. - E6C01

What is the function of hysteresis in a comparator?

Select	Answer
A	To cause the output to change states continually
B	To increase the sensitivity
C	To prevent input noise from causing unstable output signals
D	To allow the comparator to be used with AC input signals

28. - E6D05

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

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

29. - E6E02

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

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

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. - E7A02

What is the function of a decade counter?

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

32. - E7B10

In Figure E7-1, what is the purpose of R1 and R2?

Select	Answer
A	Self bias
B	Load resistors
C	Feedback
D	Voltage divider bias

33. - E7C02

Which of the following is a property of a T-network with series capacitors and a parallel shunt inductor?

Select	Answer
A	It is a high-pass filter
B	It is a low-pass filter
C	It is a band-pass filter
D	It is a notch filter

34. - E7D03

What device is typically used as a stable voltage reference in a linear voltage regulator?

Select	Answer
A	A tunnel diode
B	A Zener diode
C	An SCR
D	A varactor diode

35. - E7E09

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

Select	Answer
A	Automatic limiting occurs
B	A beat frequency is generated
C	Mixer blanking occurs
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. - E7G11

What absolute voltage gain can be expected from the circuit in Figure E7-3 when R1 is 3300 ohms and RF is 47 kilohms?

Select	Answer
A	0.07
B	14
C	7
D	28

38. - E7H07

How can an oscillator's microphonic responses be reduced?

Select	Answer
A	Reduce noise on the oscillator's power supply
B	Mechanically isolate the oscillator circuitry from its enclosure
C	Use NP0 capacitors
D	Increase the bias voltage

39. - E8A09

How many different input levels can be encoded by an analog-to-digital converter with 8-bit resolution?

Select	Answer
A	8
B	256 divided by the gain of the input amplifier
C	256
D	8 multiplied by the gain of the input amplifier

40. - E8B11

What is digital time division multiplexing?

Select	Answer
A	Two or more signals are quadrature modulated to increase bandwidth efficiency
B	Two or more signals are arranged to share discrete time slots of a data transmission
C	Two or more data streams share the same channel by transmitting time of transmission as the sub-carrier
D	Two or more data streams are assigned to discrete sub-carriers on an FM transmitter

41. - E8C11

What is the relationship between symbol rate and baud?

Select	Answer
A	Symbol rate is only used for packet-based modes
B	Baud is only used for RTTY
C	Baud is twice the symbol rate
D	They are the same

42. - E8D04

What is the primary effect of extremely short rise or fall time on a CW signal?

Select	Answer
A	The generation of RF harmonics
B	The generation of key clicks
C	More difficult to copy
D	Limits data speed

43. - E9A05

What is included in the total resistance of an antenna system?

Select	Answer
A	Radiation resistance plus transmission resistance
B	Radiation resistance plus loss resistance
C	Radiation resistance plus space impedance
D	Transmission-line resistance plus radiation resistance

44. - E9B01

In the antenna radiation pattern shown in Figure E9-1, what is the beamwidth?

Select	Answer
A	25 degrees
B	75 degrees
C	50 degrees
D	30 degrees

45. - E9C10

Which of the following describes a Zepp antenna?

Select	Answer
A	A vertical array capable of quickly changing the direction of maximum radiation by changing phasing lines
B	An omni-directional antenna commonly used for satellite communications
C	A dipole constructed from zip cord
D	An end-fed dipole antenna

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

47. - E9E09

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

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

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

49. - E9G09

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

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

50. - E9H11

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

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

Figure E5-1

Figure E7-1

Figure E7-3

Figure E9-1