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

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1. - E1A12

With your transceiver displaying the carrier frequency of CW signals, you hear a DX station's CQ on 3.500 MHz. Is it legal to return the call using CW on the same frequency?

Select	Answer
A	Yes, the displayed frequency is within the 80 meter CW band segment
B	No, U.S. stations are not permitted to use CW emissions below 3.525 MHz
C	No, one of the sidebands of the CW signal will be out of the band
D	Yes, the DX station initiated the contact

2. - E1B07

What is the highest modulation index permitted at the highest modulation frequency for angle modulation below 29.0 MHz?

Select	Answer
A	2.0
B	0.5
C	1.0
D	3.0

3. - E1C04

What is meant by IARP?

Select	Answer
A	An international amateur radio permit that allows U.S. amateurs to operate in certain countries of the Americas
B	A forecast of intermittent aurora radio propagation
C	An indication of increased antenna reflected power
D	The internal amateur radio practices policy of the FCC

4. - E1D02

What is the amateur satellite service?

Select	Answer
A	A radio communications service using amateur radio stations on satellites
B	A radio navigation service using satellites for the purpose of self training, intercommunication and technical studies carried out by amateurs
C	A spacecraft launching service for amateur-built satellites
D	A radio communications service using stations on Earth satellites for public service broadcast

5. - E1E08

To which of the following examinees may a VE not administer an examination?

Select	Answer
A	Friends of the VE
B	Relatives of the VE as listed in the FCC rules
C	Employees of the VE
D	All of these choices are correct

6. - E1F09

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

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

7. - E2A06

On what band would a satellite receive signals if it were operating in mode U/V?

Select	Answer
A	29.5 MHz - 29.7 MHz
B	50.0 MHz - 50.2 MHz
C	144 MHz - 146 MHz
D	435 MHz - 438 MHz

8. - E2B03

How is an interlaced scanning pattern generated in a fast-scan (NTSC) television system?

Select	Answer
A	By scanning two fields simultaneously
B	By scanning each field from bottom to top
C	By scanning odd numbered lines in one field and even numbered lines in the next
D	By scanning lines from left to right in one field and right to left in the next

9. - E2C06

During a VHF/UHF contest, in which band segment would you expect to find the highest level of activity?

Select	Answer
A	In the middle of the band, usually 25 kHz above the national calling frequency
B	In the weak signal segment of the band, with most of the activity near the calling frequency
C	In the middle of each band, usually on the national calling frequency
D	At the top of each band, usually in a segment reserved for contests

10. - E2D11

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

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

11. - E2E08

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

Select	Answer
A	AMTOR
B	RTTY
C	Hellschreiber
D	PACTOR

12. - E3A07

Atmospheric ducts capable of propagating microwave signals often form over what geographic feature?

Select	Answer
A	Urban areas
B	Mountain ranges
C	Forests
D	Bodies of water

13. - E3B09

At what time of year is Sporadic E propagation most likely to occur?

Select	Answer
A	Around the equinoxes, especially the spring equinox
B	Around the solstices, especially the summer solstice
C	Around the equinoxes, especially the fall equinox
D	Around the solstices, especially the winter solstice

14. - E3C04

What does the value of Bz (B sub Z) represent?

Select	Answer
A	Direction and strength of the interplanetary magnetic field
B	Geomagnetic field stability
C	Duration of long-delayed echoes
D	Critical frequency for vertical transmissions

15. - E4A10

Which of the following displays multiple digital signal states simultaneously?

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

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

17. - E4C11

Which of the following is a desirable amount of selectivity for an amateur SSB phone receiver?

Select	Answer
A	1 kHz
B	2.4 kHz
C	4.8 kHz
D	4.2 kHz

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

19. - E4E02

Which of the following types of receiver noise can often be reduced with a DSP noise filter?

Select	Answer
A	Power line noise
B	All of these choices are correct
C	Broadband white noise
D	Ignition noise

20. - E5A09

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

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

21. - E5B10

What is the relationship between the current through an inductor and the voltage across an inductor?

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

22. - E5C06

What does the impedance 50-j25 represent?

Select	Answer
A	50 ohms resistance in series with 25 ohms inductive reactance
B	25 ohms resistance in series with 50 ohms inductive reactance
C	25 ohms resistance in series with 50 ohms capacitive reactance
D	50 ohms resistance in series with 25 ohms capacitive reactance

23. - E5D17

How many watts are consumed in a circuit having a power factor of 0.6 if the input is 200VAC at 5 amperes?

Select	Answer
A	200 watts
B	600 watts
C	1600 watts
D	1000 watts

24. - E6A16

What are the majority charge carriers in N-type semiconductor material?

Select	Answer
A	Free protons
B	Holes
C	Free electrons
D	Free neutrons

25. - E6B01

What is the most useful characteristic of a Zener diode?

Select	Answer
A	A constant voltage drop under conditions of varying current
B	An internal capacitance that varies with the applied voltage
C	A negative resistance region
D	A constant current drop under conditions of varying voltage

26. - E6C08

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

Select	Answer
A	1
B	3
C	4
D	2

27. - E6D05

What is one reason for using ferrite cores rather than powdered-iron in an inductor?

Select	Answer
A	Ferrite toroids are easier to use with surface mount technology
B	Ferrite toroids generally require fewer turns to produce a given inductance value
C	Ferrite toroids generally have lower initial permeability
D	Ferrite toroids generally have better temperature stability

28. - E6E05

Which of the following noise figure values is typical of a low-noise UHF preamplifier?

Select	Answer
A	2 dB
B	-10 dB
C	-20 dBm
D	44 dBm

29. - E6F08

Why are optoisolators often used in conjunction with solid state circuits when switching 120VAC?

Select	Answer
A	Optoisolators provide a low impedance link between a control circuit and a power circuit
B	Optoisolators eliminate the effects of reflected light in the control circuit
C	Optoisolators provide impedance matching between the control circuit and power circuit
D	Optoisolators provide a very high degree of electrical isolation between a control circuit and the circuit being switched

30. - E7A03

Which of the following can divide the frequency of a pulse train by 2?

Select	Answer
A	A multiplexer
B	An OR gate
C	An XOR gate
D	A flip-flop

31. - E7B08

How can an RF power amplifier be neutralized?

Select	Answer
A	By reducing the driving power
B	By feeding a 180-degree out-of-phase portion of the output back to the input
C	By increasing the driving power
D	By feeding an in-phase component of the output back to the input

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

33. - E7D06

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

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

34. - E7E05

What circuit is added to an FM transmitter to boost the higher audio frequencies?

Select	Answer
A	A heterodyne suppressor
B	An audio prescaler
C	A pre-emphasis network
D	A de-emphasis network

35. - E7F06

What is the minimum number of bits required for an analog-to-digital converter to sample a signal with a range of 1 volt at a resolution of 1 millivolt?

Select	Answer
A	8 bits
B	6 bits
C	4 bits
D	10 bits

36. - E7G02

What is the effect of ringing in a filter?

Select	Answer
A	Undesired oscillations added to the desired signal
B	A reduction in high frequency response
C	An echo caused by a long time delay
D	Partial cancellation of the signal over a range of frequencies

37. - E7H04

How is positive feedback supplied in a Colpitts oscillator?

Select	Answer
A	Through a capacitive divider
B	Through link coupling
C	Through a neutralizing capacitor
D	Through a tapped coil

38. - E8A02

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

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

39. - E8B04

What is the modulation index of an FM-phone signal having a maximum carrier deviation of plus or minus 6 kHz when modulated with a 2 kHz modulating frequency?

Select	Answer
A	2000
B	3
C	6000
D	1/3

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	5.76 kHz
D	4.8 kHz

41. - E8D02

What spread spectrum communications technique uses a high speed binary bit stream to shift the phase of an RF carrier?

Select	Answer
A	Direct sequence
B	Phase compandored spread spectrum
C	Frequency hopping
D	Binary phase-shift keying

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	632 watts
B	159 watts
C	63.2 watts
D	252 watts

43. - E9B07

How does the total amount of radiation emitted by a directional gain antenna compare with the total amount of radiation emitted from an isotropic antenna, assuming each is driven by the same amount of power?

Select	Answer
A	The total amount of radiation from the directional antenna is increased by the gain of the antenna
B	They are the same
C	The radiation from the isotropic antenna is 2.15 dB stronger than that from the directional antenna
D	The total amount of radiation from the directional antenna is stronger by its front-to-back ratio

44. - E9C07

What is the approximate feed point impedance at the center of a two-wire folded dipole antenna?

Select	Answer
A	50 ohms
B	450 ohms
C	300 ohms
D	72 ohms

45. - E9D04

Why should an HF mobile antenna loading coil have a high ratio of reactance to resistance?

Select	Answer
A	To minimize the Q
B	To minimize losses
C	To swamp out harmonics
D	To maximize losses

46. - E9E02

What is the name of an antenna matching system that matches an unbalanced feed line to an antenna by feeding the driven element both at the center of the element and at a fraction of a wavelength to one side of center?

Select	Answer
A	The epsilon match
B	The stub match
C	The gamma match
D	The delta match

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	Velocity factor
B	Standing wave ratio
C	Characteristic impedance
D	Surge impedance

48. - E9G10

What do the arcs on a Smith chart represent?

Select	Answer
A	Points with constant reactance
B	SWR
C	Frequency
D	Points with constant resistance

49. - E9H11

What characteristic of a cardioid pattern antenna is useful for direction finding?

Select	Answer
A	Broad band response
B	A very sharp peak
C	High-radiation angle
D	A very sharp single null

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

Figure E6-5

Figure E7-3