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

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1. - E1A09

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

Select	Answer
A	Notify the nearest FCC Field Engineer's office
B	Notify the originating station that the communication does not comply with FCC rules
C	Discontinue forwarding the communication as soon as you become aware of it
D	Discontinue forwarding all messages

2. - E1B01

Which of the following constitutes a spurious emission?

Select	Answer
A	Any transmitted signal that unintentionally interferes with another licensed radio station
B	An emission outside its necessary bandwidth that can be reduced or eliminated without affecting the information transmitted
C	A signal transmitted to prevent its detection by any station other than the intended recipient
D	An amateur station transmission made at random without the proper call sign identification

3. - E1C09

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

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

4. - E1D06

Which of the following is a requirement of a space station?

Select	Answer
A	The space station must cease all transmissions after 5 years
B	The space station must be capable of changing its orbit whenever such a change is ordered by NASA
C	The space station must be capable of terminating transmissions by telecommand when directed by the FCC
D	All of these choices are correct

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

6. - E1F11

Which of the following best describes one of the standards that must be met by an external RF power amplifier if it is to qualify for a grant of FCC certification?

Select	Answer
A	It must exhibit a gain of 0 dB or less over its full output range
B	It must satisfy the FCC's spurious emission standards when operated at the lesser of 1500 watts or its full output power
C	It must be capable of external RF switching between its input and output networks
D	It must produce full legal output when driven by not more than 5 watts of mean RF input power

7. - E2A05

What do the letters in a satellite's mode designator specify?

Select	Answer
A	The polarization of uplink and downlink signals
B	The location of the ground control station
C	Power limits for uplink and downlink transmissions
D	The uplink and downlink frequency ranges

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

9. - E2C11

How should you generally identify your station when attempting to contact a DX station during a contest or in a pileup?

Select	Answer
A	Send your full call sign once or twice
B	Send only the last two letters of your call sign until you make contact
C	Send the call sign of the DX station three times, the words "this is", then your call sign three times
D	Send your full call sign and grid square

10. - E2D11

Which of the following data are used by the APRS network to communicate your location?

Select	Answer
A	Polar coordinates
B	Time and frequency
C	Radio direction finding spectrum analysis
D	Latitude and longitude

11. - E2E11

What is the difference between direct FSK and audio FSK?

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

12. - E3A02

What characterizes libration fading of an EME signal?

Select	Answer
A	The returning echo is several Hertz lower in frequency than the transmitted signal
B	A gradual loss of signal as the Sun rises
C	A fluttery irregular fading
D	A slow change in the pitch of the CW signal

13. - E3B12

What is the primary characteristic of chordal hop propagation?

Select	Answer
A	Signals reflected back toward the transmitting station
B	Propagation away from the great circle bearing between stations
C	Successive ionospheric reflections without an intermediate reflection from the ground
D	Propagation across the geomagnetic equator

14. - E3C09

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

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

15. - E4A11

Which of the following is good practice when using an oscilloscope probe?

Select	Answer
A	Never use a DC-coupled probe to measure an AC circuit
B	Keep the signal ground connection of the probe as short as possible
C	All of these choices are correct
D	Never use a high impedance probe to measure a low impedance circuit

16. - E4B07

What do the subscripts of S parameters represent?

Select	Answer
A	Relative quality of the data
B	Frequency order of the measurements
C	The relative time between measurements
D	The port or ports at which measurements are made

17. - E4C16

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

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

18. - E4D01

What is meant by the blocking dynamic range of a receiver?

Select	Answer
A	The difference in dB between the noise floor and the third order intercept point
B	The minimum difference in dB between two signals which produce third order intermodulation products greater than the noise floor
C	The minimum difference in dB between the levels of two FM signals which will cause one signal to block the other
D	The difference in dB between the noise floor and the level of an incoming signal which will cause 1 dB of gain compression

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

20. - E5A12

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

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

21. - E5B12

What is admittance?

Select	Answer
A	The turns ratio of a transformer
B	The inverse of impedance
C	The term for the gain of a field effect transistor
D	The unit used for Q factor

22. - E5C14

Which point on Figure E5-2 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 2
B	Point 6
C	Point 5
D	Point 4

23. - E5D03

What is microstrip?

Select	Answer
A	Short lengths of coax mounted on printed circuit boards to minimize time delay between microwave circuits
B	Miniature coax used for low power applications
C	Lightweight transmission line made of common zip cord
D	Precision printed circuit conductors above a ground plane that provide constant impedance interconnects at microwave frequencies

24. - E6A07

Which of the following indicates that a silicon NPN junction transistor is biased on?

Select	Answer
A	Base-to-emitter voltage of approximately 0.6 to 0.7 volts
B	Base-to-emitter voltage of approximately 6 to 7 volts
C	Base-to-emitter resistance of approximately 6 to 7 ohms
D	Base-to-emitter resistance of approximately 0.6 to 0.7 ohms

25. - E6B08

Which of the following describes a type of semiconductor diode?

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

26. - E6C14

What is the primary advantage of using a Programmable Gate Array (PGA) in a logic circuit?

Select	Answer
A	Complex logic functions can be created in a single integrated circuit
B	All of these choices are correct
C	Many similar gates are less expensive than a mixture of gate types
D	A PGA contains its own internal power supply

27. - E6D02

What is the equivalent circuit of a quartz crystal?

Select	Answer
A	Motional inductance and loss resistance in series, paralleled with motional capacitance and a capacitor representing electrode and stray capacitance
B	Motional capacitance, motional inductance, loss resistance, and a capacitor representing electrode and stray capacitance all in series
C	Motional capacitance, motional inductance, loss resistance, and a capacitor representing electrode and stray capacitance all in parallel
D	Motional capacitance, motional inductance, and loss resistance in series, all in parallel with a shunt capacitor representing electrode and stray capacitance

28. - E6E10

What is the packaging technique in which leadless components are soldered directly to circuit boards?

Select	Answer
A	Direct soldering
B	Virtual lead mounting
C	Surface mount
D	Stripped lead

29. - E6F13

What is a liquid crystal display (LCD)?

Select	Answer
A	A modern replacement for a quartz crystal oscillator which displays its fundamental frequency
B	A frequency-determining unit for a transmitter or receiver
C	A display that uses a glowing liquid to remain brightly lit in dim light
D	A display utilizing a crystalline liquid and polarizing filters which becomes opaque when voltage is applied

30. - E7A09

What logical operation is performed by an exclusive NOR gate?

Select	Answer
A	It produces logic "1" at its output if any single input is logic "1"
B	It produces logic "0" at its output only if all inputs are logic "0"
C	It produces logic "1" at its output only if all inputs are logic "1"
D	It produces logic "0" at its output if any single input is logic "1"

31. - E7B02

What is a Class D amplifier?

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

32. - E7C03

What advantage does a Pi-L-network have over a regular Pi-network for impedance matching between the final amplifier of a vacuum-tube transmitter and an antenna?

Select	Answer
A	Greater transformation range
B	Greater harmonic suppression
C	Lower losses
D	Higher efficiency

33. - E7D02

What is one characteristic of a switching electronic voltage regulator?

Select	Answer
A	The controlled device's duty cycle is changed to produce a constant average output voltage
B	It gives a ramp voltage at its output
C	The resistance of a control element is varied in direct proportion to the line voltage or load current
D	It is generally less efficient than a linear regulator

34. - E7E11

Which type of detector is used for demodulating SSB signals?

Select	Answer
A	Phase comparator
B	Product detector
C	Discriminator
D	Phase detector

35. - E7F03

What type of digital signal processing filter is used to generate an SSB signal?

Select	Answer
A	A Hilbert-transform filter
B	An elliptical filter
C	A notch filter
D	An adaptive filter

36. - E7G01

What is the typical output impedance of an integrated circuit op-amp?

Select	Answer
A	1000 ohms
B	100 ohms
C	Very high
D	Very low

37. - 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 also known as a monostable multivibrator
C	An electronic circuit consisting of a precision push-pull amplifier with a differential input
D	An electronic servo loop consisting of a ratio detector, reactance modulator, and voltage-controlled oscillator

38. - E8A05

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

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

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	FM compressibility
C	Modulation index
D	Quieting index

40. - E8C11

What is the relationship between symbol rate and baud?

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

41. - E8D06

Which of the following indicates likely overmodulation of an AFSK signal such as PSK or MFSK?

Select	Answer
A	Strong ALC action
B	High reflected power
C	Rapid signal fading
D	Harmonics on higher bands

42. - E9A02

What antenna has no gain in any direction?

Select	Answer
A	Isotropic antenna
B	Yagi
C	Half-wave dipole
D	Quarter-wave vertical

43. - E9B10

What is the principle of a Method of Moments analysis?

Select	Answer
A	A wire is modeled as a series of segments, each having a uniform value of current
B	A wire is modeled as a single sine-wave current generator
C	A wire is modeled as a series of points, each having a distinct location in space
D	A wire is modeled as a series of segments, each having a distinct value of voltage across it

44. - E9C13

What is the main effect of placing a vertical antenna over an imperfect ground?

Select	Answer
A	It reduces losses in the radiating portion of the antenna
B	It causes increased SWR
C	It reduces low-angle radiation
D	It changes the impedance angle of the matching network

45. - E9D06

What happens to the bandwidth of an antenna as it is shortened through the use of loading coils?

Select	Answer
A	No change occurs
B	It is increased
C	It becomes flat
D	It is decreased

46. - E9E06

What is the equivalent lumped-constant network for a hairpin matching system of a 3-element Yagi?

Select	Answer
A	Pi-L-network
B	A series capacitor
C	A shunt inductor
D	Pi-network

47. - E9F16

Which of the following is a significant difference between foam dielectric coaxial cable and solid dielectric cable, assuming all other parameters are the same?

Select	Answer
A	Foam dielectric has lower loss per unit of length
B	All of these choices are correct
C	Foam dielectric has higher velocity factor
D	Foam dielectric has lower safe operating voltage limits

48. - E9G07

On the Smith chart shown in Figure E9-3, what is the only straight line shown?

Select	Answer
A	The resistance axis
B	The current axis
C	The voltage axis
D	The reactance axis

49. - E9H10

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

Select	Answer
A	By increasing either the number of wire turns in the loop or the area of the loop structure or both
B	By winding adjacent turns in opposing directions
C	By reducing the permeability of the loop shield
D	By increasing the number of wire turns in the loop and reducing the area of the loop structure

50. - E0A03

Which of the following would be a practical way to estimate whether the RF fields produced by an amateur radio station are within permissible MPE limits?

Select	Answer
A	Use a hand calculator plus Smith-chart equations to calculate the fields
B	Use an antenna modeling program to calculate field strength at accessible locations
C	All of the choices are correct
D	Use a calibrated antenna analyzer

Figure E5-2

Figure E9-3