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. - E1A09

What action or actions should you take if your digital message forwarding station inadvertently forwards a communication that violates FCC rules?

Select	Answer
A	Notify the originating station that the communication does not comply with FCC rules
B	All these choices are correct
C	Discontinue forwarding the communication as soon as you become aware of it
D	Notify the nearest FCC Field Engineers office

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	3 kHz
C	20 kHz
D	10 kHz

4. - E1C09

What is the highest modulation index permitted at the highest modulation frequency for angle modulation below 29.0 MHz?

Select	Answer
A	0.5
B	2.0
C	3.0
D	1.0

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 located in a satellite or a balloon more than 50 kilometers above the surface of the Earth
C	An amateur station that transmits communications to initiate, modify or terminate functions of a space station
D	An amateur station that receives telemetry from a satellite or balloon more than 50 kilometers above the surface of the Earth

6. - E1E03

What is a Volunteer Examiner Coordinator?

Select	Answer
A	A person who has volunteered to prepare amateur operator license examinations
B	An organization that has entered into an agreement with the FCC to coordinate, prepare, and administer amateur operator license examinations
C	A person who has volunteered to administer amateur operator license examinations
D	The person who has entered into an agreement with the FCC to be the VE session manager

7. - E1F06

Under what circumstances might the FCC issue a Special Temporary Authority (STA) to an amateur station?

Select	Answer
A	To provide for experimental amateur communications
B	To provide temporary operation while awaiting normal licensing
C	To provide additional spectrum for personal use
D	To allow regular operation on Land Mobile channels

8. - E2A04

What is meant by the term mode? as applied to an amateur radio satellite?

Select	Answer
A	Whether the satellite is in a polar or equatorial orbit
B	The satellite's orientation with respect to the Earth
C	The satellite's uplink and downlink frequency bands
D	Whether the satellite is in a low earth or geostationary orbit

9. - E2B04

How is color information sent in analog SSTV?

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

10. - E2C01

What indicator is required to be used by U.S.-licensed operators when operating a station via remote control and the remote transmitter is located in the U.S.?

Select	Answer
A	/R# where # is the district of the remote station
B	No additional indicator is required
C	/ followed by the ARRL Section of the remote station
D	/ followed by the USPS two-letter abbreviation for the state in which the remote station is located

11. - E2D08

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

Select	Answer
A	Disconnect
B	Connect
C	Acknowledgement
D	Unnumbered Information

12. - E2E05

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

Select	Answer
A	PACTOR
B	RTTY
C	PSK31
D	MFSK

13. - E3A10

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

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

14. - E3B01

What is transequatorial propagation?

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

15. - E3C04

What does the value of Bz (B sub Z) represent?

Select	Answer
A	Direction and strength of the interplanetary magnetic field
B	Critical frequency for vertical transmissions
C	Geomagnetic field stability
D	Duration of long-delayed echoes

16. - E4A02

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

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

17. - E4B04

Which S parameter represents input port return loss or reflection coefficient (equivalent to VSWR)?

Select	Answer
A	S11
B	S12
C	S22
D	S21

18. - E4C15

What is reciprocal mixing?

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

19. - E4D06

What is the term for spurious signals generated by the combination of two or more signals in a non-linear device or circuit?

Select	Answer
A	Adjacent channel interference
B	Intermodulation
C	Amplifier desensitization
D	Neutralization

20. - E4E09

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

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

21. - E5A12

What is the half-power bandwidth of a resonant circuit that has a resonant frequency of 3.7 MHz and a Q of 118?

Select	Answer
A	436.6 kHz
B	15.7 kHz
C	31.4 kHz
D	218.3 kHz

22. - E5B02

What letter is commonly used to represent susceptance?

Select	Answer
A	G
B	Y
C	B
D	X

23. - E5C06

What does the impedance 50-j25 represent?

Select	Answer
A	25 ohms resistance in series with 50 ohms inductive reactance
B	50 ohms resistance in series with 25 ohms inductive reactance
C	25 ohms resistance in series with 50 ohms capacitive reactance
D	50 ohms resistance in series with 25 ohms capacitive reactance

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 reduce noise figure
D	To increase compensating capacitance

25. - E6A08

What term indicates the frequency at which the grounded-base current gain of a transistor has decreased to 0.7 of the gain obtainable at 1 kHz?

Select	Answer
A	Corner frequency
B	Alpha rejection frequency
C	Alpha cutoff frequency
D	Beta cutoff frequency

26. - E6B11

What is used to control the attenuation of RF signals by a PIN diode?

Select	Answer
A	Capacitance of an RF coupling capacitor
B	A sub-harmonic pump signal
C	Forward DC bias current
D	Reverse voltage larger than the RF signal

27. - E6C07

What best describes a pull-up or pull-down resistor?

Select	Answer
A	A resistor connected to an op-amp output that prevents signals from exceeding the power supply voltage
B	A resistor in a keying circuit used to reduce key clicks
C	A resistor that ensures that an oscillator frequency does not drift
D	A resistor connected to the positive or negative supply line used to establish a voltage when an input or output is an open circuit

28. - E6D11

Which type of core material decreases inductance when inserted into a coil?

Select	Answer
A	Ceramic
B	Ferrite
C	Powdered iron
D	Brass

29. - E6E05

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

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

30. - E6F06

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

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

31. - E7A04

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

Select	Answer
A	2
B	1
C	8
D	4

32. - E7B02

What is a Class D amplifier?

Select	Answer
A	An amplifier that uses drift-mode FETs for high efficiency
B	A low power amplifier that uses a differential amplifier for improved linearity
C	A frequency doubling amplifier
D	A type of amplifier that uses switching technology to achieve high efficiency

33. - E7C11

Which of the following describes a receiving filter's ability to reject signals occupying an adjacent channel?

Select	Answer
A	Shape factor
B	Noise factor
C	Passband ripple
D	Phase response

34. - E7D03

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

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

35. - E7E09

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

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

36. - E7F01

What is meant by direct digital conversion as applied to software defined radios?

Select	Answer
A	Incoming RF is digitized by an analog-to-digital converter without being mixed with a local oscillator signal
B	Software is converted from source code to object code during operation of the receiver
C	Incoming RF is converted to a control voltage for a voltage controlled oscillator
D	A switching mixer is used to generate I and Q signals directly from the RF input

37. - E7G09

What will be the output voltage of the circuit shown in Figure E7-3 if R1 is 1000 ohms, RF is 10,000 ohms, and 0.23 volts DC is applied to the input?

Select	Answer
A	0.23 volts
B	-0.23 volts
C	2.3 volts
D	-2.3 volts

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 circuit also known as a monostable multivibrator
D	An electronic servo loop consisting of a ratio detector, reactance modulator, and voltage-controlled oscillator

39. - E8A08

Why would a direct or flash conversion analog-to-digital converter be useful for a software defined radio?

Select	Answer
A	All these choices are correct
B	Very low power consumption decreases frequency drift
C	Immunity to out-of-sequence coding reduces spurious responses
D	Very high speed allows digitizing high frequencies

40. - E8B08

What describes Orthogonal Frequency Division Multiplexing?

Select	Answer
A	A digital mode for narrow-band, slow-speed transmissions
B	A frequency modulation technique that uses non-harmonically related frequencies
C	A digital modulation technique using subcarriers at frequencies chosen to avoid intersymbol interference
D	A bandwidth compression technique using Fourier transforms

41. - E8C05

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

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

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	Limits data speed
C	More difficult to copy
D	The generation of key clicks

43. - E9A09

What is antenna efficiency?

Select	Answer
A	Total resistance divided by radiation resistance
B	Radiation resistance divided by transmission resistance
C	Effective radiated power divided by transmitter output
D	Radiation resistance divided by total resistance

44. - E9B11

What is a disadvantage of decreasing the number of wire segments in an antenna model below 10 segments per half-wavelength?

Select	Answer
A	The computed feed point impedance may be incorrect
B	The antenna will become mechanically unstable
C	Ground conductivity will not be accurately modeled
D	The resulting design will favor radiation of harmonic energy

45. - E9C07

What is the approximate feed point impedance at the center of a two-wire folded dipole antenna?

Select	Answer
A	300 ohms
B	450 ohms
C	50 ohms
D	72 ohms

46. - E9D05

What usually occurs if a Yagi antenna is designed solely for maximum forward gain?

Select	Answer
A	The frequency response is widened over the whole frequency band
B	The SWR is reduced
C	The front-to-back ratio increases
D	The front-to-back ratio decreases

47. - E9E07

What parameter describes the interactions at the load end of a mismatched transmission line?

Select	Answer
A	Reflection coefficient
B	Velocity factor
C	Dielectric constant
D	Characteristic impedance

48. - E9F04

What impedance does a 1/2-wavelength transmission line present to a generator when the line is shorted at the far end?

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

49. - E9G02

What type of coordinate system is used in a Smith chart?

Select	Answer
A	Resistance lines and reactance chords
B	Voltage lines and current chords
C	Voltage circles and current arcs
D	Resistance circles and reactance arcs

50. - E9H09

What is a Pennant antenna?

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

Figure E7-3