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

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1. - E1A04

With your transceiver displaying the carrier frequency of phone signals, you hear a DX station calling CQ on 3.601 MHz LSB. Is it legal to return the call using lower sideband on the same frequency?

Select	Answer
A	Yes, because the displayed frequency is within the 75 meter phone band segment
B	Yes, because the DX station initiated the contact
C	No, the sideband will extend beyond the edge of the phone band segment
D	No, U.S. stations are not permitted to use phone emissions below 3.610 MHz

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

3. - E1C01

What is a remotely controlled station?

Select	Answer
A	A station operated away from its regular home location
B	A station controlled by someone other than the licensee
C	A station operating under automatic control
D	A station controlled indirectly through a control link

4. - E1D09

Which UHF amateur service bands have frequencies available for a space station?

Select	Answer
A	70 cm and 13 cm
B	70 cm and 33 cm
C	70 cm only
D	33 cm and 13 cm

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. - E1F09

Which of the following conditions apply when transmitting spread spectrum emission?

Select	Answer
A	The transmission must not be used to obscure the meaning of any communication
B	A station transmitting SS emission must not cause harmful interference to other stations employing other authorized emissions
C	All of these choices are correct
D	The transmitting station must be in an area regulated by the FCC or in a country that permits SS emissions

7. - E2A01

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

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

8. - E2B11

What is the function of the Vertical Interval Signaling (VIS) code sent as part of an SSTV transmission?

Select	Answer
A	To identify the SSTV mode being used
B	To identify the call sign of the station transmitting
C	To provide vertical synchronization
D	To lock the color burst oscillator in color SSTV images

9. - E2C08

Which of the following contacts may be confirmed through the U.S. QSL bureau system?

Select	Answer
A	Special event contacts between stations in the U.S.
B	Repeater contacts between U.S. club members
C	Contacts using tactical call signs
D	Contacts between a U.S. station and a non-U.S. station

10. - E2D01

Which of the following digital modes is especially designed for use for meteor scatter signals?

Select	Answer
A	APRS
B	WSPR
C	FSK441
D	Hellschreiber

11. - E2E06

What is the most common data rate used for HF packet?

Select	Answer
A	48 baud
B	1200 baud
C	110 baud
D	300 baud

12. - E3A15

What is an electromagnetic wave?

Select	Answer
A	A wave consisting of an electric field and a magnetic field oscillating at right angles to each other
B	A wave consisting of two electric fields at parallel right angles to each other
C	A wave of alternating current, in the core of an electromagnet
D	A wave consisting of two magnetic fields at right angles to each other

13. - E3B14

What happens to linearly polarized radio waves that split into ordinary and extraordinary waves in the ionosphere?

Select	Answer
A	They become elliptically polarized
B	They are bent toward the magnetic poles
C	Their polarization is randomly modified
D	They become phase-locked

14. - E3C13

What type of polarization is best for ground-wave propagation?

Select	Answer
A	Circular
B	Horizontal
C	Elliptical
D	Vertical

15. - E4A10

Which of the following displays multiple digital signal states simultaneously?

Select	Answer
A	Logic analyzer
B	Modulation monitor
C	Network analyzer
D	Bit error rate tester

16. - E4B15

Which of the following can be used as a relative measurement of the Q for a series-tuned circuit?

Select	Answer
A	The inductance to capacitance ratio
B	The bandwidth of the circuit's frequency response
C	The frequency shift
D	The resonant frequency of the circuit

17. - E4C07

What does the MDS of a receiver represent?

Select	Answer
A	The multiplex distortion stability
B	The minimum discernible signal
C	The maximum detectable spectrum
D	The meter display sensitivity

18. - E4D14

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

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

19. - E4E10

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

Select	Answer
A	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
B	The interfering signal can be several kHz in width and usually repeats at regular intervals across a HF band
C	All of these choices are correct
D	The interfering signal may drift slowly across the HF spectrum

20. - E5A09

How is the Q of an RLC parallel resonant circuit calculated?

Select	Answer
A	Reactance of either the inductance or capacitance divided by the resistance
B	Reactance of either the inductance or capacitance multiplied by the resistance
C	Reactance of the inductance multiplied by the reactance of the capacitance
D	Resistance divided by the reactance of either the inductance or capacitance

21. - E5B04

What is the time constant of a circuit having two 220 microfarad capacitors and two 1 megohm resistors, all in parallel?

Select	Answer
A	55 seconds
B	220 seconds
C	440 seconds
D	110 seconds

22. - E5C05

What is the name of the diagram used to show the phase relationship between impedances at a given frequency?

Select	Answer
A	Venn diagram
B	Phasor diagram
C	Near field diagram
D	Far field diagram

23. - E5D16

What is the power factor of an R-L circuit having a 30 degree phase angle between the voltage and the current?

Select	Answer
A	0.5
B	1.73
C	0.577
D	0.866

24. - E6A03

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

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

25. - E6B13

What type of bias is required for an LED to emit light?

Select	Answer
A	Inductive bias
B	Zero bias
C	Forward bias
D	Reverse bias

26. - E6C14

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

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

27. - E6D16

What is the common name for a capacitor connected across a transformer secondary that is used to absorb transient voltage spikes?

Select	Answer
A	Clipper capacitor
B	Feedback capacitor
C	Trimmer capacitor
D	Snubber capacitor

28. - E6E06

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

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

29. - E6F13

What is a liquid crystal display (LCD)?

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

30. - E7A01

Which is a bi-stable circuit?

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

31. - E7B01

For what portion of a signal cycle does a Class AB amplifier operate?

Select	Answer
A	Less than 180 degrees
B	Exactly 180 degrees
C	The entire cycle
D	More than 180 degrees but less than 360 degrees

32. - E7C08

Which of the following factors has the greatest effect in helping determine the bandwidth and response shape of a crystal ladder filter?

Select	Answer
A	The DC voltage applied to the quartz crystal
B	The relative frequencies of the individual crystals
C	The gain of the RF stage preceding the filter
D	The amplitude of the signals passing through the filter

33. - E7D06

What is the purpose of Q1 in the circuit shown in Figure E7-3?

Select	Answer
A	It provides negative feedback to improve regulation
B	It increases the current-handling capability of the regulator
C	It provides D1 with current
D	It provides a constant load for the voltage source

34. - E7E12

What is a frequency discriminator stage in a FM receiver?

Select	Answer
A	A circuit for filtering two closely adjacent signals
B	A circuit for detecting FM signals
C	An automatic band-switching circuit
D	An FM generator circuit

35. - E7F08

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

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

36. - E7G11

What absolute voltage gain can be expected from the circuit in Figure E7-4 when R1 is 3300 ohms and RF is 47 kilohms?

Select	Answer
A	0.07
B	28
C	14
D	7

37. - E7H09

What type of frequency synthesizer circuit uses a phase accumulator, lookup table, digital to analog converter, and a low-pass anti-alias filter?

Select	Answer
A	A direct digital synthesizer
B	A hybrid synthesizer
C	A phase locked loop synthesizer
D	A diode-switching matrix synthesizer

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 voltage with a D'Arsonval meter
C	By using an absorption wave meter
D	By measuring the heating effect in a known resistor

39. - E8B05

What is the deviation ratio of an FM-phone signal having a maximum frequency swing of plus-or-minus 5 kHz when the maximum modulation frequency is 3 kHz?

Select	Answer
A	0.6
B	60
C	0.167
D	1.67

40. - E8C09

Which is the name of a digital code where each preceding or following character changes by only one bit?

Select	Answer
A	Binary Coded Decimal Code
B	Gray code
C	Excess 3 code
D	Extended Binary Coded Decimal Interchange Code

41. - E8D04

What is the primary effect of extremely short rise or fall time on a CW signal?

Select	Answer
A	Limits data speed
B	The generation of key clicks
C	More difficult to copy
D	The generation of RF harmonics

42. - E9A17

What is the effective radiated power of a repeater station with 200 watts transmitter power output, 2 dB feed line loss, 2.8 dB duplexer loss, 1.2 dB circulator loss, and 7 dBi antenna gain?

Select	Answer
A	159 watts
B	63.2 watts
C	632 watts
D	252 watts

43. - E9B08

How can the approximate beam-width in a given plane of a directional antenna be determined?

Select	Answer
A	Measure the ratio of the signal strengths of the radiated power lobes from the front and side of the antenna
B	Draw two imaginary lines through the ends of the elements and measure the angle between the lines
C	Note the two points where the signal strength of the antenna is 3 dB less than maximum and compute the angular difference
D	Measure the ratio of the signal strengths of the radiated power lobes from the front and rear of the antenna

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 reduces low-angle radiation
C	It causes increased SWR
D	It changes the impedance angle of the matching network

45. - E9D09

What is the function of a loading coil used as part of an HF mobile antenna?

Select	Answer
A	To lower the losses
B	To increase the SWR bandwidth
C	To cancel capacitive reactance
D	To lower the Q

46. - E9E06

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

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

47. - E9F01

What is the velocity factor of a transmission line?

Select	Answer
A	The velocity of the wave in the transmission line divided by the velocity of light in a vacuum
B	The ratio of the characteristic impedance of the line to the terminating impedance
C	The index of shielding for coaxial cable
D	The velocity of the wave in the transmission line multiplied by the velocity of light in a vacuum

48. - E9G05

What type of chart is shown in Figure E9-3?

Select	Answer
A	Free space radiation directivity chart
B	Azimuth angle radiation pattern chart
C	Smith chart
D	Elevation angle radiation pattern chart

49. - E9H08

What is the function of a sense antenna?

Select	Answer
A	It increases the sensitivity of a DF antenna array
B	It modifies the pattern of a DF antenna array to provide a null in one direction
C	It allows DF antennas to receive signals at different vertical angles
D	It provides diversity reception that cancels multipath signals

50. - E0A09

Which insulating material commonly used as a thermal conductor for some types of electronic devices is extremely toxic if broken or crushed and the particles are accidentally inhaled?

Select	Answer
A	Beryllium Oxide
B	Zinc oxide
C	Uranium Hexafluoride
D	Mica

Figure E7-3

Figure E7-4

Figure E9-3