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

2. - E1B01

Which of the following constitutes a spurious emission?

Select	Answer
A	An emission outside its necessary bandwidth that can be reduced or eliminated without affecting the information transmitted
B	An amateur station transmission made at random without the proper call sign identification
C	Any transmitted signal that unintentionally interferes with another licensed radio station
D	A signal transmitted to prevent its detection by any station other than the intended recipient

3. - E1C12

What types of communications may be transmitted to amateur stations in foreign countries?

Select	Answer
A	Business-related messages for non-profit organizations
B	Communications incidental to the purpose of the amateur service and remarks of a personal nature
C	Messages intended for connection to users of the maritime satellite service
D	All of these choices are correct

4. - E1D06

Which of the following is a requirement of a space station?

Select	Answer
A	The space station must be capable of terminating transmissions by telecommand when directed by the FCC
B	The space station must cease all transmissions after 5 years
C	The space station must be capable of changing its orbit whenever such a change is ordered by NASA
D	All of these choices are correct

5. - E1E05

What is the minimum passing score on amateur operator license examinations?

Select	Answer
A	Minimum passing score of 77%
B	Minimum passing score of 70%
C	Minimum passing score of 74%
D	Minimum passing score of 80%

6. - E1F01

On what frequencies are spread spectrum transmissions permitted?

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

7. - E2A14

What technology is used to track, in real time, balloons carrying amateur radio transmitters?

Select	Answer
A	Doppler shift of beacon signals
B	APRS
C	Bandwidth compressed LORAN
D	Radar

8. - E2B17

What is the approximate bandwidth of a slow-scan TV signal?

Select	Answer
A	2 MHz
B	3 kHz
C	600 Hz
D	6 MHz

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 relay calls to and from a DX station
C	To handle the receiving and sending of confirmation cards for a DX station
D	To allocate frequencies for DXpeditions

10. - E2D04

What is the purpose of digital store-and-forward functions on an Amateur Radio satellite?

Select	Answer
A	To upload operational software for the transponder
B	To delay download of telemetry between satellites
C	To store digital messages in the satellite for later download by other stations
D	To relay messages between satellites

11. - E2E12

Which type of control is used by stations using the Automatic Link Enable (ALE) protocol?

Select	Answer
A	Automatic
B	Remote
C	ALE can use any type of control
D	Local

12. - E3A12

What is the cause of auroral activity?

Select	Answer
A	Meteor showers concentrated in the extreme northern and southern latitudes
B	The interaction in the F2 layer between the solar wind and the Van Allen belt
C	The interaction in the E layer of charged particles from the Sun with the Earth's magnetic field
D	A low sunspot level combined with tropospheric ducting

13. - E3B04

What is meant by the terms extraordinary and ordinary waves?

Select	Answer
A	Refracted rays and reflected waves
B	Independent waves created in the ionosphere that are elliptically polarized
C	Long path and short path waves
D	Extraordinary waves describe rare long skip propagation compared to ordinary waves which travel shorter distances

14. - E3C14

Why does the radio-path horizon distance exceed the geometric horizon?

Select	Answer
A	E-region skip
B	Downward bending due to density variations in the atmosphere
C	Downward bending due to aurora refraction
D	D-region skip

15. - E4A11

Which of the following is good practice when using an oscilloscope probe?

Select	Answer
A	Never use a high impedance probe to measure a low impedance circuit
B	Never use a DC-coupled probe to measure an AC circuit
C	All of these choices are correct
D	Keep the signal ground connection of the probe as short as possible

16. - E4B11

How should an antenna analyzer be connected when measuring antenna resonance and feed point impedance?

Select	Answer
A	Connect the analyzer via a high-impedance transformer to the antenna
B	Loosely couple the analyzer near the antenna base
C	Loosely couple the antenna and a dummy load to the analyzer
D	Connect the antenna feed line directly to the analyzer's connector

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. - E4D11

Why are third-order intermodulation products created within a receiver of particular interest compared to other products?

Select	Answer
A	Third-order intermodulation produces three products for every input signal within the band of interest
B	The third-order product of two signals which are in the band of interest is also likely to be within the band
C	The third-order intercept is much higher than other orders
D	Third-order products are an indication of poor image rejection

19. - E4E01

Which of the following types of receiver noise can often be reduced by use of a receiver noise blanker?

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

20. - E5A17

What is the result of increasing the Q of an impedance-matching circuit?

Select	Answer
A	Matching bandwidth is decreased
B	Matching bandwidth is increased
C	It has no effect on impedance matching
D	Matching range is increased

21. - E5B01

What is the term for the time required for the capacitor in an RC circuit to be charged to 63.2% of the applied voltage?

Select	Answer
A	One time constant
B	An exponential rate of one
C	One exponential period
D	A time factor of one

22. - E5C15

Which point in Figure E5-2 best represents the impedance of a series circuit consisting of a 300 ohm resistor and an 18 microhenry inductor at 3.505 MHz?

Select	Answer
A	Point 3
B	Point 1
C	Point 7
D	Point 8

23. - E5D08

What type of energy is stored in an electromagnetic or electrostatic field?

Select	Answer
A	Kinetic energy
B	Thermodynamic energy
C	Electromechanical energy
D	Potential energy

24. - E6A17

What are the names of the three terminals of a field-effect transistor?

Select	Answer
A	Gate 1, gate 2, drain
B	Gate, drain, source
C	Emitter, base 1, base 2
D	Emitter, base, collector

25. - E6B06

Which of the following is a common use of a hot-carrier diode?

Select	Answer
A	As a VHF/UHF mixer or detector
B	As balanced mixers in FM generation
C	As a variable capacitance in an automatic frequency control circuit
D	As a constant voltage reference in a power supply

26. - E6C01

What is the function of hysteresis in a comparator?

Select	Answer
A	To cause the output to change states continually
B	To allow the comparator to be used with AC input signal
C	To increase the sensitivity
D	To prevent input noise from causing unstable output signals

27. - E6D12

What is the definition of saturation in a ferrite core inductor?

Select	Answer
A	The ability of the inductor's core to store magnetic energy has been exceeded
B	The inductor windings are over coupled
C	Adjacent inductors become over-coupled
D	The inductor's voltage rating is exceeded causing a flashover

28. - E6E12

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

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

29. - E6F05

Which describes an optical shaft encoder?

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

30. - E7A12

What type of logic defines "0" as a high voltage?

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

31. - E7B10

In Figure E7-1, what is the purpose of R1 and R2?

Select	Answer
A	Self bias
B	Load resistors
C	Fixed bias
D	Feedback

32. - E7C14

Which mode is most affected by non-linear phase response in a receiver IF filter?

Select	Answer
A	Video
B	Single-Sideband voice
C	Digital
D	Meteor scatter

33. - E7D05

Which of the following types of linear voltage regulator places a constant load on the unregulated voltage source?

Select	Answer
A	A constant current source
B	A shunt current source
C	A shunt regulator
D	A series regulator

34. - E7E08

What are the principal frequencies that appear at the output of a mixer circuit?

Select	Answer
A	Two and four times the original frequency
B	The sum, difference and square root of the input frequencies
C	1.414 and 0.707 times the input frequency
D	The two input frequencies along with their sum and difference frequencies

35. - E7F14

Which of the following would allow a digital signal processing filter to create a sharper filter response?

Select	Answer
A	More taps
B	Double-precision math routines
C	Higher data rate
D	Complex phasor representations

36. - E7G06

Which of the following is the most appropriate use of an op-amp active filter?

Select	Answer
A	As a high-pass filter used to block RFI at the input to receivers
B	For smoothing power supply output
C	As a low-pass filter used between a transmitter and a transmission line
D	As an audio filter in a receiver

37. - E7H06

Which of the following oscillator circuits are commonly used in VFOs?

Select	Answer
A	Negative feedback and balanced feedback
B	Armstrong and deForest
C	Pierce and Zener
D	Colpitts and Hartley

38. - E8A02

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

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

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	3000
B	1000
C	0.3
D	3

40. - E8C04

What technique is used to minimize the bandwidth requirements of a PSK31 signal?

Select	Answer
A	Use of trapezoidal data pulses
B	Zero-sum character encoding
C	Use of sinusoidal data pulses
D	Reed-Solomon character encoding

41. - E8D03

How does the spread spectrum technique of frequency hopping work?

Select	Answer
A	A pseudo-random binary bit stream is used to shift the phase of an RF carrier very rapidly in a particular sequence
B	The frequency of the transmitted signal is changed very rapidly according to a particular sequence also used by the receiving station
C	If interference is detected by the receiver it will signal the transmitter to change frequencies
D	If interference is detected by the receiver it will signal the transmitter to wait until the frequency is clear

42. - E9A18

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

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

43. - E9B03

In the antenna radiation pattern shown in Figure E9-1, what is the front-to-side ratio?

Select	Answer
A	24 dB
B	14 dB
C	18 dB
D	12 dB

44. - E9C07

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

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

45. - E9D08

What happens as the Q of an antenna increases?

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

46. - E9E07

What term best describes the interactions at the load end of a mismatched transmission line?

Select	Answer
A	Characteristic impedance
B	Velocity factor
C	Dielectric constant
D	Reflection coefficient

47. - E9F10

What impedance does a 1/8 wavelength transmission line present to a generator when the line is shorted at the far end?

Select	Answer
A	The same as the characteristic impedance of the line
B	An inductive reactance
C	A capacitive reactance
D	The same as the input impedance to the final generator stage

48. - E9G10

What do the arcs on a Smith chart represent?

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

49. - E9H04

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

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

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	Make sure signals from your station are less than the controlled MPE limits
C	Make sure signals from your station are less than the uncontrolled MPE limits
D	Advise your neighbors of the results of your tests

Figure E5-2

Figure E7-1

Figure E9-1