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

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1. - E1A14

What is the maximum bandwidth for a data emission on 60 meters?

Select	Answer
A	1.5 kHz
B	170 Hz
C	2.8 kHz
D	60 Hz

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

3. - E1C09

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

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

4. - E1D04

What is an Earth station in the amateur satellite service?

Select	Answer
A	An amateur station that is not able to communicate using amateur satellites
B	Any amateur station on the surface of the Earth
C	An amateur station within 50 km of the Earth's surface intended for communications with amateur stations by means of objects in space
D	An amateur station that transmits telemetry consisting of measurement of upper atmosphere

5. - E1E09

What may be the penalty for a VE who fraudulently administers or certifies an examination?

Select	Answer
A	A sentence of up to one year in prison
B	Revocation of the VE's amateur station license grant and the suspension of the VE's amateur operator license grant
C	A fine of up to $1000 per occurrence
D	All of these choices are correct

6. - E1F07

When may an amateur station send a message to a business?

Select	Answer
A	When transmitting international third-party communications
B	When the control operator is employed by the FCC or another government agency
C	When neither the amateur nor his or her employer has a pecuniary interest in the communications
D	When the total money involved does not exceed $25

7. - E2A14

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

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

8. - E2B17

What is the approximate bandwidth of a slow-scan TV signal?

Select	Answer
A	3 kHz
B	600 Hz
C	2 MHz
D	6 MHz

9. - E2C10

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

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

10. - E2D03

Which of the following digital modes is especially useful for EME communications?

Select	Answer
A	FSK441
B	PACTOR III
C	Olivia
D	JT65

11. - E2E11

What is the difference between direct FSK and audio FSK?

Select	Answer
A	Audio FSK can be performed anywhere in the transmit chain
B	Audio FSK has a superior frequency response
C	Direct FSK uses a DC-coupled data connection
D	Direct FSK applies the data signal to the transmitter VFO

12. - E3A12

What is the cause of auroral activity?

Select	Answer
A	The interaction in the F2 layer between the solar wind and the Van Allen belt
B	A low sunspot level combined with tropospheric ducting
C	The interaction in the E layer of charged particles from the Sun with the Earth's magnetic field
D	Meteor showers concentrated in the extreme northern and southern latitudes

13. - E3B07

Which of the following could account for hearing an echo on the received signal of a distant station?

Select	Answer
A	Transmit frequency is higher than the MUF
B	Receipt of a signal by more than one path
C	Meteor scatter
D	High D layer absorption

14. - E3C09

How does the intensity of an X3 flare compare to that of an X2 flare?

Select	Answer
A	Twice as great
B	Four times as great
C	50 percent greater
D	10 percent greater

15. - E4A12

Which of the following procedures is an important precaution to follow when connecting a spectrum analyzer to a transmitter output?

Select	Answer
A	Attenuate the transmitter output going to the spectrum analyzer
B	Match the antenna to the load
C	Use high quality double shielded coaxial cables to reduce signal losses
D	All of these choices are correct

16. - E4B11

How should an antenna analyzer be connected when measuring antenna resonance and feed point impedance?

Select	Answer
A	Connect the antenna feed line directly to the analyzer's connector
B	Loosely couple the antenna and a dummy load to the analyzer
C	Loosely couple the analyzer near the antenna base
D	Connect the analyzer via a high-impedance transformer to the antenna

17. - E4C13

How does a narrow-band roofing filter affect receiver performance?

Select	Answer
A	It improves dynamic range by attenuating strong signals near the receive frequency
B	All of these choices are correct
C	It improves intelligibility by using low Q circuitry to reduce ringing
D	It improves sensitivity by reducing front end noise

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

19. - E4E14

What is one type of electrical interference that might be caused by the operation of 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	A whining type noise that continually pulses off and on
D	The appearance of unstable modulated or unmodulated signals at specific frequencies

20. - E5A03

What is the magnitude of the impedance of a series RLC circuit at resonance?

Select	Answer
A	Approximately equal to circuit resistance
B	Approximately equal to inductive reactance
C	High, as compared to the circuit resistance
D	Approximately equal to capacitive reactance

21. - E5B07

What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 500 ohms, R is 1 kilohm, and XL is 250 ohms?

Select	Answer
A	68.2 degrees with the voltage leading the current
B	68.2 degrees with the voltage lagging the current
C	14.0 degrees with the voltage lagging the current
D	14.0 degrees with the voltage leading the current

22. - E5C10

When using rectangular coordinates to graph the impedance of a circuit, what does the vertical axis represent?

Select	Answer
A	The sum of the reactive and resistive components
B	The difference between the resistive and reactive components
C	Resistive component
D	Reactive component

23. - E5D04

Why are short connections necessary at microwave frequencies?

Select	Answer
A	To reduce phase shift along the connection
B	To reduce noise figure
C	Because of ground reflections
D	To increase neutralizing resistance

24. - E6A15

Which semiconductor material contains excess holes in the outer shell of electrons?

Select	Answer
A	Bipolar-type
B	Superconductor-type
C	P-type
D	N-type

25. - E6B10

In Figure E6-3, what is the schematic symbol for a light-emitting diode?

Select	Answer
A	6
B	1
C	7
D	5

26. - E6C10

In Figure E6-5, what is the schematic symbol for a NOR gate?

Select	Answer
A	3
B	2
C	4
D	1

27. - E6D01

How many turns will be required to produce a 5-microhenry inductor using a powdered-iron toroidal core that has an inductance index (A L) value of 40 microhenrys/100 turns?

Select	Answer
A	141 turns
B	35 turns
C	79 turns
D	13 turns

28. - E6E08

How is voltage from a power supply normally furnished to the most common type of monolithic microwave integrated circuit (MMIC)?

Select	Answer
A	Directly to the bias voltage (VCC IN) lead
B	Through a capacitor and RF choke connected to the amplifier input lead
C	Through a resistor and/or RF choke connected to the amplifier output lead
D	MMICs require no operating bias

29. - E6F14

Which of the following is true of LCD displays?

Select	Answer
A	All of these choices are correct
B	They may be hard view through polarized lenses
C	They only display alphanumeric symbols
D	They are hard to view in high ambient light conditions

30. - E7A02

What is the function of a decade counter digital IC?

Select	Answer
A	It produces one output pulse for every ten input pulses
B	It adds two decimal numbers together
C	It produces ten output pulses for every input pulse
D	It decodes a decimal number for display on a seven segment LED display

31. - E7B14

Why are switching amplifiers more efficient than linear amplifiers?

Select	Answer
A	The power transistor is at saturation or cut off most of the time, resulting in low power dissipation
B	Switching amplifiers use push-pull circuits
C	Linear amplifiers have high gain resulting in higher harmonic content
D	Switching amplifiers operate at higher voltages

32. - E7C14

Which mode is most affected by non-linear phase response in a receiver IF filter?

Select	Answer
A	Digital
B	Meteor scatter
C	Single-Sideband voice
D	Video

33. - E7D10

What is the primary reason that a high-frequency switching type high voltage power supply can be both less expensive and lighter in weight than a conventional power supply?

Select	Answer
A	It uses a large power factor compensation capacitor to create free power from the unused portion of the AC cycle
B	It uses a diode bridge rectifier for increased output
C	The high frequency inverter design uses much smaller transformers and filter components for an equivalent power output
D	The inverter design does not require any output filtering

34. - E7E09

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

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

35. - 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	6 bits
B	4 bits
C	8 bits
D	10 bits

36. - E7G06

Which of the following is the most appropriate use of an op-amp active filter?

Select	Answer
A	For smoothing power supply output
B	As an audio filter in a receiver
C	As a low-pass filter used between a transmitter and a transmission line
D	As a high-pass filter used to block RFI at the input to receivers

37. - E7H12

Which of the following must be done to insure that a crystal oscillator provides the frequency specified by the crystal manufacturer?

Select	Answer
A	Bias the crystal at a specified current
B	Provide the crystal with a specified parallel capacitance
C	Bias the crystal at a specified voltage
D	Provide the crystal with a specified parallel inductance

38. - E8A12

What is an advantage of using digital signals instead of analog signals to convey the same information?

Select	Answer
A	Less complex circuitry is required for digital signal generation and detection
B	Digital signals can be regenerated multiple times without error
C	Digital signals always occupy a narrower bandwidth
D	All of these choices are correct

39. - E8B01

What is the term for the ratio between the frequency deviation of an RF carrier wave and the modulating frequency of its corresponding FM-phone signal?

Select	Answer
A	Percentage of modulation
B	Modulation index
C	Quieting index
D	FM compressibility

40. - E8C04

What technique is used to minimize the bandwidth requirements of a PSK31 signal?

Select	Answer
A	Use of trapezoidal data pulses
B	Zero-sum character encoding
C	Use of sinusoidal data pulses
D	Reed-Solomon character encoding

41. - E8D02

What spread spectrum communications technique uses a high speed binary bit stream to shift the phase of an RF carrier?

Select	Answer
A	Phase compandored spread spectrum
B	Binary phase-shift keying
C	Frequency hopping
D	Direct sequence

42. - E9A06

How does the beamwidth of an antenna vary as the gain is increased?

Select	Answer
A	It is essentially unaffected
B	It increases arithmetically
C	It decreases
D	It increases geometrically

43. - E9B16

How many elevation lobes appear in the forward direction of the antenna radiation pattern shown in Figure E9-2?

Select	Answer
A	3
B	7
C	4
D	1

44. - E9C10

Which of the following describes a Zepp antenna?

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

45. - E9D07

What is an advantage of using top loading in a shortened HF vertical antenna?

Select	Answer
A	Higher losses
B	Lower Q
C	Greater structural strength
D	Improved radiation efficiency

46. - E9E09

Which of these matching systems is an effective method of connecting a 50 ohm coaxial cable feed line to a grounded tower so it can be used as a vertical antenna?

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

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

48. - E9G04

What are the two families of circles and arcs that make up a Smith chart?

Select	Answer
A	Resistance and reactance
B	Resistance and voltage
C	Voltage and impedance
D	Reactance and voltage

49. - E9H02

Which is generally true for low band (160 meter and 80 meter) receiving antennas?

Select	Answer
A	Atmospheric noise is so high that gain over a dipole is not important
B	Low loss coax transmission line is essential for good performance
C	All of these choices are correct
D	They must be erected at least 1/2 wavelength above the ground to attain good directivity

50. - E0A11

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

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

Figure E6-3

Figure E6-5

Figure E9-2