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

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1. - E1A05

What is the maximum power output permitted on the 60 meter band?

Select	Answer
A	50 watts PEP effective radiated power relative to an isotropic radiator
B	100 watts PEP effective radiated power relative to the gain of a half-wave dipole
C	100 watts PEP effective radiated power relative to an isotropic radiator
D	50 watts PEP effective radiated power relative to a dipole

2. - E1B07

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

Select	Answer
A	3.0
B	2.0
C	1.0
D	0.5

3. - E1C10

What types of amateur stations may automatically retransmit the radio signals of other amateur stations?

Select	Answer
A	Only auxiliary, beacon or space stations
B	Only beacon, repeater or space stations
C	Only earth stations, repeater stations or model craft
D	Only auxiliary, repeater or space stations

4. - E1D07

Which amateur service HF bands have frequencies authorized for space stations?

Select	Answer
A	Only the 40 m, 20 m, 17 m, 15 m and 10 m bands
B	Only the 40 m, 30 m, 20 m, 15 m, 12 m and 10 m bands
C	All HF bands
D	Only the 40 m, 20 m, 17 m, 15 m, 12 m and 10 m bands

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 collect and send the documents to the NCVEC for grading
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 submit the application document to the coordinating VEC according to the coordinating VEC instructions

6. - E1F04

Which of the following geographic descriptions approximately describes "Line A"?

Select	Answer
A	A line roughly parallel to and west of the U.S. Atlantic coastline
B	A line roughly parallel to and east of the U.S. Pacific coastline
C	A line roughly parallel to and north of the U.S.-Mexican border and Gulf coastline
D	A line roughly parallel to and south of the U.S.-Canadian border

7. - E2A09

What do the terms L band and S band specify with regard to satellite communications?

Select	Answer
A	The 23 centimeter and 13 centimeter bands
B	Which sideband to use
C	The 2 meter and 70 centimeter bands
D	FM and Digital Store-and-Forward systems

8. - E2B16

Which is a video standard used by North American Fast Scan ATV stations?

Select	Answer
A	PAL
B	Scottie
C	NTSC
D	DRM

9. - E2C07

What is the Cabrillo format?

Select	Answer
A	The most common set of contest rules
B	A standard for submission of electronic contest logs
C	The rules of order for meetings between contest sponsors
D	A method of exchanging information during a contest QSO

10. - E2D08

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

Select	Answer
A	Disconnect
B	Acknowledgement
C	Unnumbered Information
D	Connect

11. - E2E03

How is the timing of JT65 contacts organized?

Select	Answer
A	Stations take turns on alternate days
B	It depends on the lunar phase
C	Alternating transmissions at 1 minute intervals
D	By exchanging ACK/NAK packets

12. - E3A17

What is meant by circularly polarized electromagnetic waves?

Select	Answer
A	Waves with an electric field bent into a circular shape
B	Waves with a rotating electric field
C	Waves produced by a loop antenna
D	Waves that circle the Earth

13. - E3B10

What is the cause of gray-line propagation?

Select	Answer
A	At mid-afternoon, the Sun heats the ionosphere decreasing radio wave refraction and the MUF
B	In darkness, solar absorption drops greatly while atmospheric ionization remains steady
C	At twilight and sunrise, D-layer absorption is low while E-layer and F-layer propagation remains high
D	At midday, the Sun super heats the ionosphere causing increased refraction of radio waves

14. - E3C06

By how much does the VHF/UHF radio horizon distance exceed the geometric horizon?

Select	Answer
A	By approximately twice the distance
B	By approximately 50 percent of the distance
C	By approximately 15 percent of the distance
D	By approximately four times the distance

15. - E4A05

What might be an advantage of a digital vs an analog oscilloscope?

Select	Answer
A	Automatic amplitude and frequency numerical readout
B	Storage of traces for future reference
C	Manipulation of time base after trace capture
D	All of these choices are correct

16. - E4B06

How much power is being absorbed by the load when a directional power meter connected between a transmitter and a terminating load reads 100 watts forward power and 25 watts reflected power?

Select	Answer
A	25 watts
B	75 watts
C	100 watts
D	125 watts

17. - E4C16

Which of the following is caused by missing codes in an SDR receiver's analog-to-digital converter?

Select	Answer
A	Excess output level
B	Distortion
C	Loss of sensitivity
D	Overload

18. - E4D10

What does a third-order intercept level of 40 dBm mean with respect to receiver performance?

Select	Answer
A	A pair of 40 dBm signals will theoretically generate a third-order intermodulation product with the same level as the input signals
B	A pair of 1 mW input signals will produce a third-order intermodulation product which is 40 dB stronger than the input signal
C	Signals less than 40 dBm will not generate audible third-order intermodulation products
D	The receiver can tolerate signals up to 40 dB above the noise floor without producing third-order intermodulation products

19. - E4E07

How can you determine if line noise interference is being generated within your home?

Select	Answer
A	By observing the AC power line waveform with an oscilloscope
B	By turning off the AC power line main circuit breaker and listening on a battery operated radio
C	By checking the power line voltage with a time domain reflectometer
D	By observing the AC power line voltage with a spectrum analyzer

20. - E5A08

What is the phase relationship between the current through and the voltage across a series resonant circuit at resonance?

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

21. - E5B12

What is admittance?

Select	Answer
A	The inverse of impedance
B	The unit used for Q factor
C	The turns ratio of a transformer
D	The term for the gain of a field effect transistor

22. - E5C05

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

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

23. - E5D04

Why are short connections necessary at microwave frequencies?

Select	Answer
A	Because of ground reflections
B	To increase neutralizing resistance
C	To reduce phase shift along the connection
D	To reduce noise figure

24. - E6A11

In Figure E6-2, what is the schematic symbol for a P-channel junction FET?

Select	Answer
A	3
B	1
C	6
D	2

25. - E6B02

What is an important characteristic of a Schottky diode as compared to an ordinary silicon diode when used as a power supply rectifier?

Select	Answer
A	Controlled reverse avalanche voltage
B	Much higher reverse voltage breakdown
C	Less forward voltage drop
D	Enhanced carrier retention time

26. - E6C13

Which of the following is an advantage of BiCMOS logic?

Select	Answer
A	Its simplicity results in much less expensive devices than standard CMOS
B	All of these choices are correct
C	It is totally immune to electrostatic damage
D	It has the high input impedance of CMOS and the low output impedance of bipolar transistors

27. - E6D11

How many turns will be required to produce a 1-mH inductor using a core that has an inductance index (A L) value of 523 millihenrys/1000 turns?

Select	Answer
A	2 turns
B	43 turns
C	229 turns
D	4 turns

28. - E6E01

Which of the following is true of a charge-coupled device (CCD)?

Select	Answer
A	It samples an analog signal and passes it in stages from the input to the output
B	It is used in a battery charger circuit
C	It is a CMOS analog-to-digital converter
D	Its phase shift changes rapidly with frequency

29. - E6F14

Which of the following is true of LCD displays?

Select	Answer
A	They are hard to view in high ambient light conditions
B	They only display alphanumeric symbols
C	They may be hard view through polarized lenses
D	All of these choices are correct

30. - E7A11

What type of logic defines "1" as a high voltage?

Select	Answer
A	Positive Logic
B	Reverse Logic
C	Negative logic
D	Assertive Logic

31. - E7B16

What is the effect of intermodulation products in a linear power amplifier?

Select	Answer
A	All of these choices are correct
B	Transmission of spurious signals
C	Low efficiency
D	Creation of parasitic oscillations

32. - E7C04

How does an impedance-matching circuit transform a complex impedance to a resistive impedance?

Select	Answer
A	It introduces transconductance to cancel the reactive part of impedance
B	It introduces negative resistance to cancel the resistive part of impedance
C	It cancels the reactive part of the impedance and changes the resistive part to a desired value
D	Network resistances are substituted for load resistances and reactances are matched to the resistances

33. - E7D11

What circuit element is controlled by a series analog voltage regulator to maintain a constant output voltage?

Select	Answer
A	Switching inductance
B	Error amplifier
C	Reference voltage
D	Pass transistor

34. - E7E10

How does a diode detector function?

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

35. - E7F09

Why is an anti-aliasing digital filter required in a digital decimator?

Select	Answer
A	It removes high-frequency signal components which would otherwise be reproduced as lower frequency components
B	It removes low frequency signal components to eliminate the need for DC restoration
C	It notches out the sampling frequency to avoid sampling errors
D	It peaks the response of the decimator, improving bandwidth

36. - E7G03

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

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

37. - E7H07

How can an oscillator's microphonic responses be reduced?

Select	Answer
A	Using the oscillator only for CW and digital signals
B	Eliminating noise on the oscillator's power supply
C	Mechanically isolating the oscillator circuitry from its enclosure
D	Use of NP0 capacitors

38. - E8A13

Which of these methods is commonly used to convert analog signals to digital signals?

Select	Answer
A	Harmonic regeneration
B	Level shifting
C	Phase reversal
D	Sequential sampling

39. - E8B01

What is the term for the ratio between the frequency deviation of an RF carrier wave and the modulating frequency of its corresponding FM-phone signal?

Select	Answer
A	Quieting index
B	Modulation index
C	Percentage of modulation
D	FM compressibility

40. - E8C03

When performing phase shift keying, why is it advantageous to shift phase precisely at the zero crossing of the RF carrier?

Select	Answer
A	It improves carrier suppression
B	This results in the least possible transmitted bandwidth for the particular mode
C	All of these choices are correct
D	It is easier to demodulate with a conventional, non-synchronous detector

41. - E8D11

What is one advantage of using ASCII code for data communications?

Select	Answer
A	It is possible to transmit both upper and lower case text
B	It uses one character as a shift code to send numeric and special characters
C	It contains fewer information bits per character than any other code
D	It includes built in error correction features

42. - E9A07

What is meant by antenna gain?

Select	Answer
A	The ratio of the radiated signal strength of an antenna in the direction of maximum radiation to that of a reference antenna
B	The final amplifier gain minus the transmission line losses
C	The ratio of the signal in the forward direction to that in the opposite direction
D	The ratio of the amount of power radiated by an antenna compared to the transmitter output power

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. - E9C02

What is the radiation pattern of two 1/4 wavelength vertical antennas spaced 1/4 wavelength apart and fed 90 degrees out of phase?

Select	Answer
A	A figure-8 end-fire along the axis of the array
B	A figure-8 broadside to the axis of the array
C	Cardioid
D	Omni-directional

45. - E9D06

What happens to the bandwidth of an antenna as it is shortened through the use of loading coils?

Select	Answer
A	No change occurs
B	It is decreased
C	It is increased
D	It becomes flat

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. - E9F07

How does ladder line compare to small-diameter coaxial cable such as RG-58 at 50 MHz?

Select	Answer
A	Lower velocity factor
B	Lower loss
C	Higher SWR
D	Smaller reflection coefficient

48. - E9G01

Which of the following can be calculated using a Smith chart?

Select	Answer
A	Impedance along transmission lines
B	Radio propagation
C	Antenna radiation pattern
D	Radiation resistance

49. - E9H10

How can the output voltage of a multiple turn receiving loop antenna be increased?

Select	Answer
A	By winding adjacent turns in opposing directions
B	By reducing the permeability of the loop shield
C	By increasing the number of wire turns in the loop and reducing the area of the loop structure
D	By increasing either the number of wire turns in the loop or the area of the loop structure or both

50. - E0A02

When evaluating RF exposure levels from your station at a neighbor's home, what must you do?

Select	Answer
A	You need only evaluate exposure levels on your own property
B	Advise your neighbors of the results of your tests
C	Make sure signals from your station are less than the uncontrolled MPE limits
D	Make sure signals from your station are less than the controlled MPE limits

Figure E6-2

Figure E9-2