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

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1. - E0A11

Which of the following injuries can result from using high-power UHF or microwave transmitters?

Select	Answer
A	Localized heating of the body from RF exposure in excess of the MPE limits
B	Blood clotting from the intense magnetic field
C	Ingestion of ozone gas from the cooling system
D	Hearing loss caused by high voltage corona discharge

2. - E1A14

Except in some parts of Alaska, what is the maximum power permitted on the 630 meter band?

Select	Answer
A	5 watts EIRP
B	1 watt EIRP
C	100 watts PEP
D	50 watts PEP

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

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

5. - E1D10

Which amateur stations are eligible to be telecommand stations of space stations (subject to the privileges of the class of operator license held by the control operator of the station)?

Select	Answer
A	Any amateur station designated by NASA
B	Any amateur station so designated by the ITU
C	All these choices are correct
D	Any amateur station so designated by the space station licensee

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. - 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 imported from a manufacturer in a country that does not require certification of RF power amplifiers
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 purchased in used condition from an amateur operator and is sold to another amateur operator for use at that operator's station

8. - E2A10

What type of satellite appears to stay in one position in the sky?

Select	Answer
A	HEO
B	Geostationary
C	Geomagnetic
D	LEO

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

10. - E2C08

Which of the following contacts may be confirmed through the U.S. QSL bureau system?

Select	Answer
A	Contacts using tactical call signs
B	Special event contacts between stations in the U.S.
C	Repeater contacts between U.S. club members
D	Contacts between a U.S. station and a non-U.S. station

11. - E2D08

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

Select	Answer
A	Disconnect
B	Connect
C	Unnumbered Information
D	Acknowledgement

12. - E2E11

What is the difference between direct FSK and audio FSK?

Select	Answer
A	Only direct FSK can be decoded by computer
B	Direct FSK can transmit faster baud rates
C	Direct FSK occupies less bandwidth
D	Direct FSK applies the data signal to the transmitter VFO, while AFSK transmits tones via phone

13. - E3A11

What is a typical range for tropospheric propagation of microwave signals?

Select	Answer
A	2500 miles
B	100 miles to 300 miles
C	10 miles to 50 miles
D	1200 miles

14. - E3B10

Why is chordal hop propagation desirable?

Select	Answer
A	The signal experiences less loss compared to multi-hop using Earth as a reflector
B	The MUF for chordal hop propagation is much lower than for normal skip propagation
C	Atmospheric noise is lower in the direction of chordal hop propagation
D	Signals travel faster along ionospheric chords

15. - E3C10

What does the 304A solar parameter measure?

Select	Answer
A	The ratio of x-ray flux to radio flux, correlated to sunspot number
B	The solar emission at 304 GHz, correlated to x-ray flare levels
C	UV emissions at 304 angstroms, correlated to the solar flux index
D	The solar wind velocity at 304 degrees from the solar equator, correlated to solar activity

16. - E4A06

What is the effect of aliasing on a digital oscilloscope caused by setting the time base too slow?

Select	Answer
A	Excessive blanking occurs, which prevents display of the signal
B	Calibration of the vertical scale is no longer valid
C	All signals will have a DC offset
D	A false, jittery low-frequency version of the signal is displayed

17. - E4B02

What is the significance of voltmeter sensitivity expressed in ohms per volt?

Select	Answer
A	The full scale reading of the voltmeter multiplied by its ohms per volt rating will indicate the input impedance of the voltmeter
B	When used as an ohmmeter, the reading in ohms divided by the ohms per volt rating will determine the voltage applied to the circuit
C	When used as a galvanometer, the reading in volts multiplied by the ohms per volt rating will determine the power drawn by the device under test
D	When used as an ammeter, the full scale reading in amps divided by ohms per volt rating will determine the size of shunt needed

18. - E4C04

What is the noise figure of a receiver?

Select	Answer
A	The ratio of the noise bandwidth in hertz to the theoretical bandwidth of a resistive network
B	The ratio of atmospheric noise to phase noise
C	The ratio of thermal noise to atmospheric noise
D	The ratio in dB of the noise generated by the receiver to the theoretical minimum noise

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	A pair of 1 mW input signals will produce a third-order intermodulation product that is 40 dB stronger than the input signal
C	The receiver can tolerate signals up to 40 dB above the noise floor without producing third-order intermodulation products
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. - 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	Ringing in the DSP filter will completely remove the spaces between the CW characters
C	Any nearby signal passing through the DSP system will overwhelm the desired signal
D	Received CW signals will appear to be modulated at the DSP clock frequency

21. - E5A10

How is the Q of an RLC series resonant circuit calculated?

Select	Answer
A	Reactance of either the inductance or capacitance multiplied by the resistance
B	Reactance of either the inductance or capacitance divided by the resistance
C	Reactance of the inductance multiplied by the reactance of the capacitance
D	Resistance divided by the reactance of either the inductance or capacitance

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

23. - E5C10

Which point on Figure E5-1 best represents the impedance of a series circuit consisting of a 400-ohm resistor and a 38-picofarad capacitor at 14 MHz?

Select	Answer
A	Point 5
B	Point 6
C	Point 4
D	Point 2

24. - E5D06

In what direction is the magnetic field oriented about a conductor in relation to the direction of electron flow?

Select	Answer
A	In a direction opposite to the current
B	In the same direction as the current
C	In a circle around the conductor
D	In all directions; omni-directional

25. - E6A01

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

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

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	Tunnel diode
D	Varactor diode

27. - E6C05

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

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

28. - E6D09

What devices are commonly used as VHF and UHF parasitic suppressors at the input and output terminals of a transistor HF amplifier?

Select	Answer
A	Electrolytic capacitors
B	Steel-core toroids
C	Butterworth filters
D	Ferrite beads

29. - E6E07

What type of transmission line is used for connections to MMICs?

Select	Answer
A	Parallel wire
B	Microstrip
C	Circular waveguide
D	Miniature coax

30. - E6F07

What is a solid-state relay?

Select	Answer
A	A mechanical relay that latches in the on or off state each time it is pulsed
B	A relay using transistors to drive the relay coil
C	A device that uses semiconductors to implement the functions of an electromechanical relay
D	A semiconductor passive delay line

31. - E7A11

What type of logic defines "1" as a high voltage?

Select	Answer
A	Assertive Logic
B	Positive Logic
C	Negative logic
D	Reverse Logic

32. - E7B12

What type of amplifier circuit is shown in Figure E7-1?

Select	Answer
A	Common emitter
B	Emitter follower
C	Common base
D	Common collector

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

34. - E7D01

How does a linear electronic voltage regulator work?

Select	Answer
A	It has a ramp voltage as its output
B	It eliminates the need for a pass transistor
C	The conduction of a control element is varied to maintain a constant output voltage
D	The control element duty cycle is proportional to the line or load conditions

35. - E7E10

How does a diode envelope detector function?

Select	Answer
A	By rectification and filtering of RF signals
B	By mixing signals with noise in the transition region of the diode
C	By sensing the change of reactance in the diode with respect to frequency
D	By breakdown of the Zener voltage

36. - E7F06

What is the minimum number of bits required for an analog-to-digital converter to sample a signal with a range of 1 volt at a resolution of 1 millivolt?

Select	Answer
A	10 bits
B	4 bits
C	8 bits
D	6 bits

37. - E7G05

How can unwanted ringing and audio instability be prevented in an op-amp RC audio filter circuit?

Select	Answer
A	Restrict gain but increase Q
B	Increase both gain and Q
C	Restrict Q but increase gain
D	Restrict both gain and Q

38. - E7H01

What are three oscillator circuits used in amateur radio equipment?

Select	Answer
A	Taft, Hartley and Pierce
B	Taft, Pierce and negative feedback
C	Colpitts, Hartley and Pierce
D	Pierce, Fenner and Beane

39. - E8A02

Which of the following is a type of analog-to-digital conversion?

Select	Answer
A	Phase reversal
B	Harmonic regeneration
C	Level shifting
D	Successive approximation

40. - E8B02

How does the modulation index of a phase-modulated emission vary with RF carrier frequency?

Select	Answer
A	It increases as the RF carrier frequency increases
B	It decreases as the RF carrier frequency increases
C	It varies with the square root of the RF carrier frequency
D	It does not depend on the RF carrier frequency

41. - E8C12

What factors affect the bandwidth of a transmitted CW signal?

Select	Answer
A	All these choices are correct
B	IF bandwidth and Q
C	Keying speed and shape factor (rise and fall time)
D	Modulation index and output power

42. - E8D09

What is considered an acceptable maximum IMD level for an idling PSK signal?

Select	Answer
A	-20 dB
B	+15 dB
C	-30 dB
D	+10 dB

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	317 watts
B	126 watts
C	300 watts
D	2000 watts

44. - E9B09

What type of computer program technique is commonly used for modeling antennas?

Select	Answer
A	Method of Moments
B	Mutual impedance analysis
C	Graphical analysis
D	Calculus differentiation with respect to physical properties

45. - E9C01

What is the radiation pattern of two 1/4-wavelength vertical antennas spaced 1/2-wavelength apart and fed 180 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 oriented along the axis of the array

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

47. - E9E07

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

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

48. - E9F12

What impedance does a 1/4-wavelength transmission line present to a generator when the line is open at the far end?

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

49. - E9G01

Which of the following can be calculated using a Smith chart?

Select	Answer
A	Impedance along transmission lines
B	Radiation resistance
C	Antenna radiation pattern
D	Radio propagation

50. - E9H10

How can the output voltage of a multiple-turn receiving loop antenna be increased?

Select	Answer
A	By utilizing high impedance wire for the coupling loop
B	By increasing the number of turns and/or the area
C	By reducing the permeability of the loop shield
D	By winding adjacent turns in opposing directions

Figure E5-1

Figure E7-1