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

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1. - E1A01

When using a transceiver that displays the carrier frequency of phone signals, which of the following displayed frequencies represents the highest frequency at which a properly adjusted USB emission will be totally within the band?

Select	Answer
A	The exact upper band edge
B	3 kHz below the upper band edge
C	300 Hz below the upper band edge
D	1 kHz below the upper band edge

2. - E1B10

What frequencies are authorized to an amateur station operating under RACES rules?

Select	Answer
A	Specific local government channels
B	All amateur service frequencies authorized to the control operator
C	Specific segments in the amateur service MF, HF, VHF and UHF bands
D	Military Auxiliary Radio System (MARS) channels

3. - E1C01

What is a remotely controlled station?

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

4. - E1D11

Which amateur stations are eligible to operate as Earth stations?

Select	Answer
A	Any amateur station, subject to the privileges of the class of operator license held by the control operator
B	Only those of General, Advanced or Amateur Extra Class operators
C	Any amateur station whose licensee has filed a pre-space notification with the FCC's International Bureau
D	Only those of Amateur Extra Class operators

5. - E1E13

Which of these choices is an acceptable method for monitoring the applicants if a VEC opts to conduct an exam session remotely?

Select	Answer
A	Have each applicant sign an affidavit stating that all session rules were followed
B	Use a real-time video link and the Internet to connect the exam session to the observing VEs
C	Record the exam session on video tape for later review by the VE team
D	The exam proctor observes the applicants and reports any violations

6. - E1F10

What is the maximum permitted transmitter peak envelope power for an amateur station transmitting spread spectrum communications?

Select	Answer
A	1.5 W
B	10 W
C	1 W
D	1.5 kW

7. - E2A08

Why should effective radiated power to a satellite which uses a linear transponder be limited?

Select	Answer
A	To avoid interfering with terrestrial QSOs
B	To avoid reducing the downlink power to all other users
C	To prevent the satellite from emitting out-of-band signals
D	To prevent creating errors in the satellite telemetry

8. - E2B14

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

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

9. - E2C08

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

Select	Answer
A	Contacts using tactical call signs
B	Repeater contacts between U.S. club members
C	Special event contacts between stations in the U.S.
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	Hellschreiber
B	APRS
C	FSK441
D	WSPR

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. - E3A10

Which type of atmospheric structure can create a path for microwave propagation?

Select	Answer
A	Wind shear
B	Temperature inversion
C	The jet stream
D	Dust devil

13. - E3B06

Which of the following amateur bands most frequently provides long-path propagation?

Select	Answer
A	10 meters
B	80 meters
C	20 meters
D	6 meters

14. - E3C05

What orientation of Bz (B sub z) increases the likelihood that incoming particles from the Sun will cause disturbed conditions?

Select	Answer
A	Southward
B	Northward
C	Eastward
D	Westward

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. - E4B16

Which S parameter represents return loss or SWR?

Select	Answer
A	S21
B	S12
C	S22
D	S11

17. - E4C15

What is usually the primary source of noise that is heard from an HF receiver with an antenna connected?

Select	Answer
A	Induction motor noise
B	Receiver front-end noise
C	Atmospheric noise
D	Detector noise

18. - E4D04

Which of the following may reduce or eliminate intermodulation interference in a repeater caused by another transmitter operating in close proximity?

Select	Answer
A	A properly terminated circulator at the output of the transmitter
B	A Class D final amplifier
C	A band-pass filter in the feed line between the transmitter and receiver
D	A Class C final amplifier

19. - E4E03

Which of the following signals might a receiver noise blanker be able to remove from desired signals?

Select	Answer
A	Signals which appear across a wide bandwidth
B	Signals which have a sharply peaked frequency distribution
C	Signals which appear at one IF but not another
D	Signals which are constant at all IF levels

20. - E5A11

What is the half-power bandwidth of a parallel resonant circuit that has a resonant frequency of 7.1 MHz and a Q of 150?

Select	Answer
A	157.8 Hz
B	315.6 Hz
C	23.67 kHz
D	47.3 kHz

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

22. - E5C05

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

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

23. - E5D10

How can the true power be determined in an AC circuit where the voltage and current are out of phase?

Select	Answer
A	By multiplying the apparent power times the power factor
B	By dividing the apparent power by the power factor
C	By dividing the reactive power by the power factor
D	By multiplying the reactive power times the power factor

24. - E6A03

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

Select	Answer
A	Only P-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 N-type semiconductor material can conduct current

25. - E6B05

What characteristic of a PIN diode makes it useful as an RF switch or attenuator?

Select	Answer
A	Reverse bias controls its forward voltage drop
B	A large region of intrinsic material
C	Extremely high reverse breakdown voltage
D	Ability to dissipate large amounts of power

26. - E6C12

What is BiCMOS logic?

Select	Answer
A	A logic device with two CMOS circuits per package
B	An integrated circuit logic family using both bipolar and CMOS transistors
C	A FET logic family based on bimetallic semiconductors
D	A logic family based on bismuth CMOS devices

27. - E6D09

What devices are commonly used as VHF and UHF parasitic suppressors at the input and output terminals of a transistor HF amplifier?

Select	Answer
A	Electrolytic capacitors
B	Ferrite beads
C	Steel-core toroids
D	Butterworth filters

28. - E6E12

Why are high-power RF amplifier ICs and transistors sometimes mounted in ceramic packages?

Select	Answer
A	Better dissipation of heat
B	Enhanced sensitivity to light
C	High-voltage insulating ability
D	To provide a low-pass frequency response

29. - E6F04

What is the photovoltaic effect?

Select	Answer
A	The conversion of electrical energy to mechanical energy
B	The conversion of light to electrical energy
C	The conversion of voltage to current when exposed to light
D	The tendency of a battery to discharge when used outside

30. - E7A06

What is a characteristic of a monostable multivibrator?

Select	Answer
A	It produces a continuous square wave oscillating between 1 and 0
B	It switches momentarily to the opposite binary state and then returns to its original state after a set time
C	It maintains a constant output voltage, regardless of variations in the input voltage
D	It stores one bit of data in either a 0 or 1 state

31. - E7B18

What is a characteristic of a grounded-grid amplifier?

Select	Answer
A	High power gain
B	Low bandwidth
C	Low input impedance
D	High filament voltage

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	L-networks cannot perform impedance transformation
C	The Q of Pi-networks can be varied depending on the component values chosen
D	Pi-networks have fewer components

33. - E7D12

What is the drop-out voltage of an analog voltage regulator?

Select	Answer
A	Maximum amount that the output voltage may decrease at rated load
B	Minimum input voltage for rated power dissipation
C	Minimum input-to-output voltage required to maintain regulation
D	Maximum amount that the output voltage drops when the input voltage is varied over its specified range

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. - E7F11

What sets the minimum detectable signal level for an SDR in the absence of atmospheric or thermal noise?

Select	Answer
A	Reference voltage level and sample width in bits
B	Sample clock phase noise
C	Missing codes and jitter
D	Data storage transfer rate

36. - E7G10

What absolute voltage gain can be expected from the circuit in Figure E7-4 when R1 is 1800 ohms and RF is 68 kilohms?

Select	Answer
A	1
B	0.03
C	76
D	38

37. - E7H11

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

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

38. - E8A04

What is "dither" with respect to analog to digital converters?

Select	Answer
A	An abnormal condition where the converter cannot settle on a value to represent the signal
B	A small amount of noise added to the input signal to allow more precise representation of a signal over time
C	An error caused by irregular quantization step size
D	A method of decimation by randomly skipping samples

39. - E8B03

What is the modulation index of an FM-phone signal having a maximum frequency deviation of 3000 Hz either side of the carrier frequency when the modulating frequency is 1000 Hz?

Select	Answer
A	0.3
B	3
C	1000
D	3000

40. - E8C07

What is the necessary bandwidth of a 4800-Hz frequency shift, 9600-baud ASCII FM transmission?

Select	Answer
A	9.6 kHz
B	15.36 kHz
C	4.8 kHz
D	5.76 kHz

41. - E8D07

What is a common cause of overmodulation of AFSK signals?

Select	Answer
A	Bit errors in the modem
B	Ground loops
C	Excessive numbers of retries
D	Excessive transmit audio levels

42. - E9A18

What term describes station output, taking into account all gains and losses?

Select	Answer
A	Power factor
B	Apparent power
C	Effective radiated power
D	Half-power bandwidth

43. - E9B15

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

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

44. - E9C08

What is a folded dipole antenna?

Select	Answer
A	A type of ground-plane antenna
B	A dipole consisting of one wavelength of wire forming a very thin loop
C	A dipole configured to provide forward gain
D	A dipole one-quarter wavelength long

45. - E9D08

What happens as the Q of an antenna increases?

Select	Answer
A	More common-mode current is present on the feed line
B	Gain is reduced
C	SWR bandwidth increases
D	SWR bandwidth decreases

46. - E9E13

What is a use for a Wilkinson divider?

Select	Answer
A	It is used to feed low-impedance loads from a high-impedance source
B	It is used to divide power equally between two 50 ohm loads while maintaining 50 ohm input impedance
C	It is used to feed high-impedance antennas from a low-impedance source
D	It divides the operating frequency of a transmitter signal so it can be used on a lower frequency band

47. - E9F14

What impedance does a 1/2 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 characteristic impedance of the line
D	The same as the output impedance of the generator

48. - E9G03

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

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

49. - E9H04

What is an advantage of using a shielded loop antenna for direction finding?

Select	Answer
A	It eliminates tracking errors caused by strong out-of-band signals
B	It automatically cancels ignition noise in mobile installations
C	It is electro statically balanced against ground, giving better nulls
D	It allows stations to communicate without giving away their position

50. - E0A10

What toxic material may be present in some electronic components such as high voltage capacitors and transformers?

Select	Answer
A	Polyethylene
B	Polytetrafluroethylene
C	Polymorphic silicon
D	Polychlorinated Biphenyls

Figure E7-4

Figure E9-2