US Amateur Radio - Amateur Extra (Element 4, 2016-2020) Practice Test

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1. - E1A07

Which amateur band requires transmission on specific channels rather than on a range of frequencies?

Select	Answer
A	60 meter band
B	17 meter band
C	12 meter band
D	30 meter band

2. - E1B09

Which amateur stations may be operated under RACES rules?

Select	Answer
A	Any FCC-licensed amateur station certified by the responsible civil defense organization for the area served
B	Any FCC-licensed amateur station except a Technician class
C	Any FCC-licensed amateur station participating in the Military Auxiliary Radio System (MARS)
D	Only those club stations licensed to Amateur Extra class operators

3. - E1C09

Which of these ranges of frequencies is available for an automatically controlled repeater operating below 30 MHz?

Select	Answer
A	29.500 MHz - 29.700 MHz
B	24.940 MHz - 24.990 MHz
C	18.110 MHz - 18.168 MHz
D	10.100 MHz - 10.150 MHz

4. - E1D05

What class of licensee is authorized to be the control operator of a space station?

Select	Answer
A	All except Technician Class
B	Only General, Advanced or Amateur Extra Class
C	Only Amateur Extra Class
D	Any class with appropriate operator privileges

5. - E1E14

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

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

6. - 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	It was purchased in used condition from an amateur operator and is sold to another amateur operator for use at that operator's station
D	The equipment dealer assembled it from a kit

7. - E2A03

What is the orbital period of an Earth satellite?

Select	Answer
A	The point of minimum height of a satellite's orbit
B	The point of maximum height of a satellite's orbit
C	The time it takes for a satellite to travel from perigee to apogee
D	The time it takes for a satellite to complete one revolution around the Earth

8. - E2B04

What is blanking in a video signal?

Select	Answer
A	Turning off the scanning beam at the conclusion of a transmission
B	Turning off the scanning beam while it is traveling from right to left or from bottom to top
C	Synchronization of the horizontal and vertical sync pulses
D	Transmitting a black and white test pattern

9. - E2C12

What might help to restore contact when DX signals become too weak to copy across an entire HF band a few hours after sunset?

Select	Answer
A	Switch to a higher frequency HF band
B	Wait 24 hours before attempting another communication on the band
C	Switch to a lower frequency HF band
D	Wait 90 minutes or so for the signal degradation to pass

10. - E2D09

Which of these digital modes has the fastest data throughput under clear communication conditions?

Select	Answer
A	170 Hz shift, 45 baud RTTY
B	300 baud packet
C	PSK31
D	AMTOR

11. - E2E04

What is indicated when one of the ellipses in an FSK crossed-ellipse display suddenly disappears?

Select	Answer
A	One of the signal filters is saturated
B	Selective fading has occurred
C	The receiver has drifted 5 kHz from the desired receive frequency
D	The mark and space signal have been inverted

12. - E3A14

From the contiguous 48 states, in which approximate direction should an antenna be pointed to take maximum advantage of aurora propagation?

Select	Answer
A	South
B	North
C	West
D	East

13. - E3B03

What is the best time of day for transequatorial propagation?

Select	Answer
A	Late at night
B	Afternoon or early evening
C	Morning
D	Noon

14. - E3C15

What might a sudden rise in radio background noise indicate?

Select	Answer
A	A solar flare has occurred
B	Long-path propagation is occurring
C	A meteor ping
D	Increased transequatorial propagation likely

15. - E4A13

How is the compensation of an oscilloscope probe typically adjusted?

Select	Answer
A	A square wave is displayed and the probe is adjusted until the horizontal portions of the displayed wave are as nearly flat as possible
B	A high frequency sine wave is displayed and the probe is adjusted for maximum amplitude
C	A DC voltage standard is displayed and the probe is adjusted until the displayed voltage is accurate
D	A frequency standard is displayed and the probe is adjusted until the deflection time is accurate

16. - E4B10

Which of the following describes a method to measure intermodulation distortion in an SSB transmitter?

Select	Answer
A	Modulate the transmitter with two harmonically related audio frequencies and observe the RF output with a peak reading wattmeter
B	Modulate the transmitter with two non-harmonically related audio frequencies and observe the RF output with a spectrum analyzer
C	Modulate the transmitter with two non-harmonically related radio frequencies and observe the RF output with a spectrum analyzer
D	Modulate the transmitter with two harmonically related audio frequencies and observe the RF output with a logic analyzer

17. - E4C16

Which of the following is caused by missing codes in an SDR receiver's analog-to-digital converter?

Select	Answer
A	Excess output level
B	Loss of sensitivity
C	Overload
D	Distortion

18. - E4D07

Which describes the most significant effect of an off-frequency signal when it is causing cross-modulation interference to a desired signal?

Select	Answer
A	The off-frequency unwanted signal is heard in addition to the desired signal
B	A large increase in background noise
C	A reduction in apparent signal strength
D	The desired signal can no longer be heard

19. - E4E06

What is a major cause of atmospheric static?

Select	Answer
A	Thunderstorms
B	Geomagnetic storms
C	Solar radio frequency emissions
D	Meteor showers

20. - E5A11

What is the half-power bandwidth of a parallel resonant circuit that has a resonant frequency of 7.1 MHz and a Q of 150?

Select	Answer
A	47.3 kHz
B	315.6 Hz
C	157.8 Hz
D	23.67 kHz

21. - 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	14 degrees with the voltage leading the current
B	76 degrees with the voltage lagging the current
C	76 degrees with the voltage leading the current
D	14 degrees with the voltage lagging the current

22. - E5C13

What coordinate system is often used to display the resistive, inductive, and/or capacitive reactance components of impedance?

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

23. - E5D01

What is the result of skin effect?

Select	Answer
A	As frequency decreases, RF current flows in a thinner layer of the conductor, closer to the surface
B	Thermal effects on the surface of the conductor decrease the impedance
C	Thermal effects on the surface of the conductor increase the impedance
D	As frequency increases, RF current flows in a thinner layer of the conductor, closer to the surface

24. - E6A05

What is the alpha of a bipolar junction transistor?

Select	Answer
A	The change of collector current with respect to emitter current
B	The change of base current with respect to collector current
C	The change of collector current with respect to base current
D	The change of collector current with respect to gate current

25. - E6B08

Which of the following describes a type of semiconductor diode?

Select	Answer
A	Metal-semiconductor junction
B	CMOS-field effect
C	Electrolytic rectifier
D	Thermionic emission diode

26. - E6C07

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

Select	Answer
A	A resistor that insures that an oscillator frequency does not drive lower over time
B	A resistor in a keying circuit used to reduce key clicks
C	A resistor connected to an op-amp output that only functions when the logic output is false
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

27. - E6D17

Why should core saturation of a conventional impedance matching transformer be avoided?

Select	Answer
A	Temporary changes of the core permeability could result
B	Magnetic flux would increase with frequency
C	RF susceptance would increase
D	Harmonics and distortion could result

28. - E6E06

What characteristics of the MMIC make it a popular choice for VHF through microwave circuits?

Select	Answer
A	Controlled gain, low noise figure, and constant input and output impedance over the specified frequency range
B	Plate current that is controlled by a control grid
C	Nearly infinite gain, very high input impedance, and very low output impedance
D	The ability to retrieve information from a single signal even in the presence of other strong signals

29. - E6F07

What is a solid state relay?

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

30. - E7A11

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

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

31. - 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 type of amplifier that uses switching technology to achieve high efficiency
D	A frequency doubling amplifier

32. - 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 notch filter
B	It is a low-pass filter
C	It is a high-pass filter
D	It is a band-pass filter

33. - E7D12

What is the drop-out voltage of an analog voltage regulator?

Select	Answer
A	Minimum input-to-output voltage required to maintain regulation
B	Minimum input voltage for rated power dissipation
C	Maximum amount that the output voltage drops when the input voltage is varied over its specified range
D	Maximum amount that the output voltage may decrease at rated load

34. - E7E04

What is one way a single-sideband phone signal can be generated?

Select	Answer
A	By using a reactance modulator followed by a mixer
B	By using a loop modulator followed by a mixer
C	By driving a product detector with a DSB signal
D	By using a balanced modulator followed by a filter

35. - E7F08

What is the function of decimation with regard to digital filters?

Select	Answer
A	Attenuating the signal
B	Reducing the effective sample rate by removing samples
C	Removing unnecessary significant digits
D	Converting data to binary code decimal form

36. - E7G05

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

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

37. - E7H13

Which of the following is a technique for providing highly accurate and stable oscillators needed for microwave transmission and reception?

Select	Answer
A	Use a temperature-controlled high Q dielectric resonator
B	Use a GPS signal reference
C	All of these choices are correct
D	Use a rubidium stabilized reference oscillator

38. - E8A05

What would be the most accurate way of measuring the RMS voltage of a complex waveform?

Select	Answer
A	By measuring the voltage with a D'Arsonval meter
B	By measuring the heating effect in a known resistor
C	By using a grid dip meter
D	By using an absorption wave meter

39. - E8B03

What is the modulation index of an FM-phone signal having a maximum frequency deviation of 3000 Hz either side of the carrier frequency when the modulating frequency is 1000 Hz?

Select	Answer
A	3
B	3000
C	1000
D	0.3

40. - E8C01

How is Forward Error Correction implemented?

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

41. - E8D09

What is considered a good minimum IMD level for an idling PSK signal?

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

42. - E9A16

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	2000 watts
C	300 watts
D	126 watts

43. - E9B09

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

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

44. - E9C10

Which of the following describes a Zepp antenna?

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

45. - E9D13

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

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

46. - E9E12

What is the primary purpose of a phasing line when used with an antenna having multiple driven elements?

Select	Answer
A	It prevents reflected power from traveling back down the feed line and causing harmonic radiation from the transmitter
B	It ensures that each driven element operates in concert with the others to create the desired antenna pattern
C	It allows single-band antennas to operate on other bands
D	It makes sure the antenna has a low-angle radiation pattern

47. - E9F15

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

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

48. - E9G11

How are the wavelength scales on a Smith chart calibrated?

Select	Answer
A	In fractions of transmission line electrical wavelength
B	In fractions of antenna electrical wavelength
C	In fractions of transmission line electrical frequency
D	In fractions of antenna electrical frequency

49. - E9H05

What is the main drawback of a wire-loop antenna for direction finding?

Select	Answer
A	It has a bidirectional pattern
B	It receives equally well in all directions
C	It is practical for use only on VHF bands
D	It is non-rotatable

50. - E0A07

How may dangerous levels of carbon monoxide from an emergency generator be detected?

Select	Answer
A	By the yellowish appearance of the gas
B	Any ordinary smoke detector can be used
C	Only with a carbon monoxide detector
D	By the odor