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

2. - E1B02

Which of the following factors might cause the physical location of an amateur station apparatus or antenna structure to be restricted?

Select	Answer
A	The location is of geographical or horticultural importance
B	The location is in an ITU Zone designated for coordination with one or more foreign governments
C	The location is of environmental importance or significant in American history, architecture, or culture
D	The location is near an area of political conflict

3. - E1C02

What is meant by automatic control of a station?

Select	Answer
A	A station operating with its output power controlled automatically
B	The use of devices and procedures for control so that the control operator does not have to be present at a control point
C	Remotely controlling a station's antenna pattern through a directional control link
D	The use of a control link between a control point and a locally controlled station

4. - E1D01

What is the definition of the term telemetry?

Select	Answer
A	One-way transmission of measurements at a distance from the measuring instrument
B	One-way transmission that initiates, modifies, or terminates the functions of a device at a distance
C	Two-way radiotelephone transmissions in excess of 1000 feet
D	Two-way single channel transmissions of data

5. - E1E10

What must the administering VEs do after the administration of a successful examination for an amateur operator license?

Select	Answer
A	They must submit the application document to the coordinating VEC according to the coordinating VEC instructions
B	They must collect and send the documents to the FCC according to instructions
C	They must collect and submit the documents to the coordinating VEC for grading
D	They must collect and send the documents to the NCVEC for grading

6. - E1F12

Who may be the control operator of an auxiliary station?

Select	Answer
A	Only General, Advanced or Amateur Extra Class operators
B	Only Amateur Extra Class operators
C	Only Technician, General, Advanced or Amateur Extra Class operators
D	Any licensed amateur operator

7. - E2A14

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

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

8. - E2B14

What aspect of an amateur slow-scan television signal encodes the brightness of the picture?

Select	Answer
A	Sync frequency
B	Sync amplitude
C	Tone frequency
D	Tone amplitude

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 only the last two letters of your call sign until you make contact
B	Send your full call sign and grid square
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 once or twice

10. - E2D08

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

Select	Answer
A	Unnumbered Information
B	Connect
C	Acknowledgement
D	Disconnect

11. - E2E02

What do the letters FEC mean as they relate to digital operation?

Select	Answer
A	First Error Correction
B	Fatal Error Correction
C	Final Error Correction
D	Forward Error Correction

12. - E3A03

When scheduling EME contacts, which of these conditions will generally result in the least path loss?

Select	Answer
A	When the Moon is at apogee
B	When the Moon is at perigee
C	When the MUF is above 30 MHz
D	When the Moon is full

13. - E3B03

What is the best time of day for transequatorial propagation?

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

14. - E3C02

What is indicated by a rising A or K index?

Select	Answer
A	Decreasing disruption of the geomagnetic field
B	Higher levels of solar UV radiation
C	Increasing disruption of the geomagnetic field
D	An increase in the critical frequency

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

16. - E4B09

What is indicated if the current reading on an RF ammeter placed in series with the antenna feed line of a transmitter increases as the transmitter is tuned to resonance?

Select	Answer
A	There is an impedance mismatch between the antenna and feed line
B	The transmitter is not properly neutralized
C	There is more power going into the antenna
D	There is possibly a short to ground in the feed line

17. - E4C02

Which of the following portions of a receiver can be effective in eliminating image signal interference?

Select	Answer
A	A properly adjusted product detector
B	A narrow IF filter
C	A front-end filter or pre-selector
D	A notch filter

18. - E4D14

Which of the following is a way to reduce the likelihood of receiver desensitization?

Select	Answer
A	Decrease the RF bandwidth of the receiver
B	Increase the receiver front end gain
C	Raise the receiver IF frequency
D	Switch from fast AGC to slow AGC

19. - E4E10

What is a common characteristic of interference caused by a touch controlled electrical device?

Select	Answer
A	The interfering signal may drift slowly across the HF spectrum
B	All of these choices are correct
C	The interfering signal sounds like AC hum on an AM receiver or a carrier modulated by 60 Hz hum on a SSB or CW receiver
D	The interfering signal can be several kHz in width and usually repeats at regular intervals across a HF band

20. - E5A02

What is resonance in an electrical circuit?

Select	Answer
A	The highest frequency that will pass current
B	The frequency at which the capacitive reactance equals the inductive reactance
C	The lowest frequency that will pass current
D	The frequency at which the reactive impedance equals the resistive impedance

21. - E5B06

What is susceptance?

Select	Answer
A	The ratio of magnetic field to electric field
B	A measure of the efficiency of a transformer
C	The inverse of reactance
D	The magnetic impedance of a circuit

22. - E5C03

Which of the following represents an inductive reactance in polar coordinates?

Select	Answer
A	A negative real part
B	A negative phase angle
C	A positive real part
D	A positive phase angle

23. - E5D13

How much power is consumed in a circuit consisting of a 100 ohm resistor in series with a 100 ohm inductive reactance drawing 1 ampere?

Select	Answer
A	70.7 Watts
B	100 Watts
C	200 Watts
D	141.4 Watts

24. - E6A03

Why does a PN-junction diode not conduct current when reverse biased?

Select	Answer
A	Only N-type semiconductor material can conduct current
B	Holes in P-type material and electrons in the N-type material are separated by the applied voltage, widening the depletion region
C	Excess holes in P-type material combine with the electrons in N-type material, converting the entire diode into an insulator
D	Only P-type semiconductor material can conduct current

25. - E6B06

Which of the following is a common use of a hot-carrier diode?

Select	Answer
A	As a VHF/UHF mixer or detector
B	As balanced mixers in FM generation
C	As a variable capacitance in an automatic frequency control circuit
D	As a constant voltage reference in a power supply

26. - E6C08

In Figure E6-5, what is the schematic symbol for a NAND gate?

Select	Answer
A	2
B	4
C	1
D	3

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

28. - E6E07

Which of the following is typically used to construct a MMIC-based microwave amplifier?

Select	Answer
A	Microstrip construction
B	Wave-soldering construction
C	Point-to-point construction
D	Ground-plane construction

29. - E6F01

What is photoconductivity?

Select	Answer
A	The decreased conductivity of an illuminated semiconductor
B	The increased conductivity of an illuminated semiconductor
C	The conversion of electromotive energy to photon energy
D	The conversion of photon energy to electromotive energy

30. - E7A01

Which is a bi-stable circuit?

Select	Answer
A	A clock
B	An "AND" gate
C	An "OR" gate
D	A flip-flop

31. - E7B14

Why are switching amplifiers more efficient than linear amplifiers?

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

32. - E7C13

What is one advantage of a Pi-matching network over an L-matching network consisting of a single inductor and a single capacitor?

Select	Answer
A	Pi-networks are designed for balanced input and output
B	Pi-networks have fewer components
C	L-networks cannot perform impedance transformation
D	The Q of Pi-networks can be varied depending on the component values chosen

33. - E7D02

What is one characteristic of a switching electronic voltage regulator?

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

34. - E7E10

How does a diode detector function?

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

35. - 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	A switching mixer is used to generate I and Q signals directly from the RF input
C	Software is converted from source code to object code during operation of the receiver
D	Incoming RF is converted to a control voltage for a voltage controlled oscillator

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 a low-pass filter used between a transmitter and a transmission line
C	As a high-pass filter used to block RFI at the input to receivers
D	As an audio filter in a receiver

37. - E7H11

What are the major spectral impurity components of direct digital synthesizers?

Select	Answer
A	Nyquist limit noise
B	Spurious signals at discrete frequencies
C	Digital conversion noise
D	Broadband noise

38. - E8A02

What type of wave has a rise time significantly faster than its fall time (or vice versa)?

Select	Answer
A	A square wave
B	A cosine wave
C	A sine wave
D	A sawtooth wave

39. - E8B11

What is digital time division multiplexing?

Select	Answer
A	Two or more data streams are assigned to discrete sub-carriers on an FM transmitter
B	Two or more signals are arranged to share discrete time slots of a data transmission
C	Two or more data streams share the same channel by transmitting time of transmission as the sub-carrier
D	Two or more signals are quadrature modulated to increase bandwidth efficiency

40. - E8C08

How does ARQ accomplish error correction?

Select	Answer
A	If errors are detected, redundant data is substituted
B	Special binary codes provide automatic correction
C	Special polynomial codes provide automatic correction
D	If errors are detected, a retransmission is requested

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	Rapid signal fading
C	Harmonics on higher bands
D	High reflected power

42. - E9A10

Which of the following choices is a way to improve the efficiency of a ground-mounted quarter-wave vertical antenna?

Select	Answer
A	Isolate the coax shield from ground
B	Shorten the radiating element
C	Reduce the diameter of the radiating element
D	Install a good radial system

43. - E9B15

What is the front-to-back ratio of the radiation pattern shown in Figure E9-2?

Select	Answer
A	15 dB
B	24 dB
C	3 dB
D	28 dB

44. - 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	Cardioid
B	A figure-8 oriented along the axis of the array
C	A figure-8 broadside to the axis of the array
D	Omni-directional

45. - E9D11

Which of the following types of conductors would be best for minimizing losses in a station's RF ground system?

Select	Answer
A	A cable with six or seven 18 gauge conductors in parallel
B	A wide flat copper strap
C	A resistive wire, such as spark plug wire
D	A single 12 gauge or 10 gauge stainless steel wire

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

47. - E9F08

What is the term for the ratio of the actual speed at which a signal travels through a transmission line to the speed of light in a vacuum?

Select	Answer
A	Characteristic impedance
B	Surge impedance
C	Velocity factor
D	Standing wave ratio

48. - E9G03

Which of the following is often determined using a Smith chart?

Select	Answer
A	Beam headings and radiation patterns
B	Impedance and SWR values in transmission lines
C	Trigonometric functions
D	Satellite azimuth and elevation bearings

49. - E9H09

Which of the following describes the construction of a receiving loop antenna?

Select	Answer
A	One or more turns of wire wound in the shape of a large open coil
B	A vertical antenna coupled to a feed line through an inductive loop of wire
C	A large circularly polarized antenna
D	A small coil of wire tightly wound around a toroidal ferrite core

50. - E0A05

What is one of the potential hazards of using microwaves in the amateur radio bands?

Select	Answer
A	The extremely high frequency energy can damage the joints of antenna structures
B	The high gain antennas commonly used can result in high exposure levels
C	Microwaves often travel long distances by ionospheric reflection
D	Microwaves are ionizing radiation

Figure E6-5

Figure E9-2