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

Logging in (or registering) will help the system to select questions that you need to focus on.

1. - E1A07

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

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

2. - E1B05

What is the National Radio Quiet Zone?

Select	Answer
A	An area in Puerto Rico surrounding the Arecibo Radio Telescope
B	An area in New Mexico surrounding the White Sands Test Area
C	An area in Florida surrounding Cape Canaveral
D	An area surrounding the National Radio Astronomy Observatory

3. - E1C07

What is meant by local control?

Select	Answer
A	Automatically manipulating local station controls
B	Direct manipulation of the transmitter by a control operator
C	Controlling a station through a local auxiliary link
D	Controlling a repeater using a portable handheld transceiver

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 terminating transmissions by telecommand when directed by the FCC
C	All of these choices are correct
D	The space station must be capable of changing its orbit whenever such a change is ordered by NASA

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

6. - E1F01

On what frequencies are spread spectrum transmissions permitted?

Select	Answer
A	Only on amateur frequencies above 50 MHz
B	Only on amateur frequencies above 222 MHz
C	Only on amateur frequencies above 420 MHz
D	Only on amateur frequencies above 144 MHz

7. - E2A01

What is the direction of an ascending pass for an amateur satellite?

Select	Answer
A	From east to west
B	From north to south
C	From south to north
D	From west to east

8. - E2B06

What is vestigial sideband modulation?

Select	Answer
A	A type of modulation in which one sideband is inverted
B	Spread spectrum modulation achieved by applying FM modulation following single sideband amplitude modulation
C	Narrow-band FM modulation achieved by filtering one sideband from the audio before frequency modulating the carrier
D	Amplitude modulation in which one complete sideband and a portion of the other are transmitted

9. - E2C05

What is the function of a DX QSL Manager?

Select	Answer
A	To run a net to allow many stations to contact a rare DX station
B	To allocate frequencies for DXpeditions
C	To handle the receiving and sending of confirmation cards for a DX station
D	To relay calls to and from a DX station

10. - E2D06

Which of the following describes a method of establishing EME contacts?

Select	Answer
A	High speed CW identification to avoid fading
B	Time synchronous transmissions alternately from each station
C	Judging optimum transmission times by monitoring beacons reflected from the Moon
D	Storing and forwarding digital messages

11. - E2E08

Which of the following HF digital modes can be used to transfer binary files?

Select	Answer
A	AMTOR
B	PACTOR
C	Hellschreiber
D	RTTY

12. - E3A02

What characterizes libration fading of an EME signal?

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

13. - E3B07

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

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

14. - E3C07

Which of the following descriptors indicates the greatest solar flare intensity?

Select	Answer
A	Class A
B	Class M
C	Class B
D	Class X

15. - E4A15

What is an advantage of a period-measuring frequency counter over a direct-count type?

Select	Answer
A	It can directly measure the modulation index of an FM transmitter
B	It does not require an expensive high-precision time base
C	It provides improved resolution of low-frequency signals within a comparable time period
D	It can run on battery power for remote measurements

16. - E4B16

Which S parameter represents return loss or SWR?

Select	Answer
A	S22
B	S11
C	S12
D	S21

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	Loss of sensitivity
C	Overload
D	Excess output level

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	A large increase in background noise
C	The off-frequency unwanted signal is heard in addition to the desired signal
D	A reduction in apparent signal strength

19. - E4E16

What current flows equally on all conductors of an unshielded multi-conductor cable?

Select	Answer
A	Common-mode current
B	Differential-mode current
C	Reactive current only
D	Return current

20. - E5A06

What is the magnitude of the circulating current within the components of a parallel LC circuit at resonance?

Select	Answer
A	It is at a maximum
B	It equals 2 multiplied by Pi, multiplied by frequency, multiplied by inductance
C	It is at a minimum
D	It equals 1 divided by the quantity 2 times Pi, multiplied by the square root of inductance L multiplied by capacitance C

21. - E5B09

What is the relationship between the current through a capacitor and the voltage across a capacitor?

Select	Answer
A	Voltage and current are 180 degrees out of phase
B	Voltage and current are in phase
C	Current leads voltage by 90 degrees
D	Voltage leads current by 90 degrees

22. - E5C10

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

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

23. - E5D07

What determines the strength of the magnetic field around a conductor?

Select	Answer
A	The diameter of the conductor
B	The amount of current flowing through the conductor
C	The resistance divided by the current
D	The ratio of the current to the resistance

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

25. - E6B07

What is the failure mechanism when a junction diode fails due to excessive current?

Select	Answer
A	Excessive inverse voltage
B	Excessive junction temperature
C	Charge carrier depletion
D	Insufficient forward voltage

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	Many similar gates are less expensive than a mixture of gate types
C	All of these choices are correct
D	A PGA contains its own internal power supply

27. - E6D03

Which of the following is an aspect of the piezoelectric effect?

Select	Answer
A	Generation of electrical energy in the presence of light
B	Mechanical deformation of material by the application of a magnetic field
C	Increased conductivity in the presence of light
D	Mechanical deformation of material by the application of a voltage

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	MMICs require no operating bias
C	Through a resistor and/or RF choke connected to the amplifier output lead
D	Through a capacitor and RF choke connected to the amplifier input lead

29. - E6F05

Which describes an optical shaft encoder?

Select	Answer
A	A digital encryption device often used to encrypt spacecraft control signals
B	A device which detects rotation of a control by interrupting a light source with a patterned wheel
C	A device which measures the strength of a beam of light using analog to digital conversion
D	A device for generating RTTY signals by means of a rotating light source

30. - E7A08

What logical operation does an OR gate perform?

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

31. - E7B15

What is one way to prevent thermal runaway in a bipolar transistor amplifier?

Select	Answer
A	All of these choices are correct
B	Use a resistor in series with the emitter
C	Neutralization
D	Select transistors with high beta

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. - E7D16

When several electrolytic filter capacitors are connected in series to increase the operating voltage of a power supply filter circuit, why should resistors be connected across each capacitor?

Select	Answer
A	All of these choices are correct
B	To provide a minimum load current to reduce voltage excursions at light loads
C	To provide a safety bleeder to discharge the capacitors when the supply is off
D	To equalize, as much as possible, the voltage drop across each capacitor

34. - E7E02

What is the function of a reactance modulator?

Select	Answer
A	To produce PM signals by using an electrically variable resistance
B	To produce AM signals by using an electrically variable resistance
C	To produce AM signals by using an electrically variable inductance or capacitance
D	To produce PM signals by using an electrically variable inductance or capacitance

35. - E7F07

What function can a Fast Fourier Transform perform?

Select	Answer
A	Converting digital signals to analog form
B	Converting analog signals to digital form
C	Converting 8-bit data to 16 bit data
D	Converting digital signals from the time domain to the frequency domain

36. - E7G01

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

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

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	All of these choices are correct
C	Use a rubidium stabilized reference oscillator
D	Use a GPS signal reference

38. - E8A08

Why would a direct or flash conversion analog-to-digital converter be useful for a software defined radio?

Select	Answer
A	Very high speed allows digitizing high frequencies
B	Very low power consumption decreases frequency drift
C	All of these choices are correct
D	Immunity to out of sequence coding reduces spurious responses

39. - E8B11

What is digital time division multiplexing?

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

40. - E8C08

How does ARQ accomplish error correction?

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

41. - E8D12

What is the advantage of including a parity bit with an ASCII character stream?

Select	Answer
A	Some types of errors can be detected SUBELEMENT E9 - ANTENNAS AND TRANSMISSION LINES [8 Exam Questions - 8 Groups] E9A Basic Antenna parameters: radiation resistance, gain, beamwidth, efficiency, beamwidth; effective radiated power, polarization E9A01 (C) What describes an isotropic antenna? A. A grounded antenna used to measure earth conductivity B. A horizontally polarized antenna used to compare Yagi antennas C. A theoretical antenna used as a reference for antenna gain D. A spacecraft antenna used to direct signals toward the earth
B	Faster transmission rate
C	The signal can overpower interfering signals
D	Foreign language characters can be sent

42. - E9A09

How is antenna efficiency calculated?

Select	Answer
A	(total resistance / radiation resistance) x 100 per cent
B	(effective radiated power / transmitter output) x 100 percent
C	(radiation resistance / total resistance) x 100 per cent
D	(radiation resistance / transmission resistance) x 100 per cent

43. - E9B06

What is the elevation angle of peak response in the antenna radiation pattern shown in Figure E9-2?

Select	Answer
A	75 degrees
B	45 degrees
C	25 degrees
D	7.5 degrees

44. - E9C04

What happens to the radiation pattern of an unterminated long wire antenna as the wire length is increased?

Select	Answer
A	The front-to-back ratio decreases
B	The lobes become more perpendicular to the wire
C	The vertical angle increases
D	The lobes align more in the direction of the wire

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 single 12 gauge or 10 gauge stainless steel wire
D	A resistive wire, such as spark plug wire

46. - E9E08

Which of the following measurements is characteristic of a mismatched transmission line?

Select	Answer
A	An SWR greater than 1:1
B	A reflection coefficient greater than 1
C	A dielectric constant greater than 1
D	An SWR less than 1:1

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

48. - E9G03

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

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

49. - E9H06

What is the triangulation method of direction finding?

Select	Answer
A	The geometric angles of sky waves from the source are used to determine its position
B	Antenna headings from several different receiving locations are used to locate the signal source
C	A fixed receiving station uses three different antennas to plot the location of the signal source
D	A fixed receiving station plots three headings to the signal source

50. - E0A08

What does SAR measure?

Select	Answer
A	Synthetic Aperture Ratio of the human body
B	The rate of RF energy reflected from stationary terrain
C	The rate at which RF energy is absorbed by the body
D	Signal Amplification Rating

Figure E9-2