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

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1. - E1A10

If an amateur station is installed aboard a ship or aircraft, what condition must be met before the station is operated?

Select	Answer
A	The amateur station must have a power supply that is completely independent of the main ship or aircraft power supply
B	The amateur operator must have an FCC Marine or Aircraft endorsement on his or her amateur license
C	Its operation must be approved by the master of the ship or the pilot in command of the aircraft
D	The amateur station operator must agree not to transmit when the main radio of the ship or aircraft is in use

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. - E1C02

What is meant by automatic control of a station?

Select	Answer
A	The use of a control link between a control point and a locally controlled station
B	The use of devices and procedures for control so that the control operator does not have to be present at a control point
C	A station operating with its output power controlled automatically
D	Remotely controlling a station's antenna pattern through a directional control link

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. - E1E11

What must the VE team do if an examinee scores a passing grade on all examination elements needed for an upgrade or new license?

Select	Answer
A	All these choices are correct
B	Photocopy all examination documents and forward them to the FCC for processing
C	Three VEs must certify that the examinee is qualified for the license grant and that they have complied with the administering VE requirements
D	Issue the examinee the new or upgrade license

6. - E1F09

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

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

7. - E2A01

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

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

8. - E2B14

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

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

9. - E2C10

Why might a DX station state that they are listening on another frequency?

Select	Answer
A	To separate the calling stations from the DX station
B	To improve operating efficiency by reducing interference
C	Because the DX station may be transmitting on a frequency that is prohibited to some responding stations
D	All of these choices are correct

10. - E2D03

Which of the following digital modes is especially useful for EME communications?

Select	Answer
A	JT65
B	PACTOR III
C	Olivia
D	FSK441

11. - E2E03

How is the timing of JT65 contacts organized?

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

12. - E3A10

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

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

13. - E3B03

What is the best time of day for transequatorial propagation?

Select	Answer
A	Afternoon or early evening
B	Late at night
C	Morning
D	Noon

14. - E3C03

Which of the following signal paths is most likely to experience high levels of absorption when the A index or K index is elevated?

Select	Answer
A	Polar paths
B	NVIS
C	Sporadic-E
D	Transequatorial propagation

15. - E4A04

What determines the upper frequency limit for a computer soundcard-based oscilloscope program?

Select	Answer
A	Q of the interface of the interface circuit
B	Analog-to-digital conversion speed of the soundcard
C	All of these choices are correct
D	Amount of memory on the soundcard

16. - E4B07

What do the subscripts of S parameters represent?

Select	Answer
A	The port or ports at which measurements are made
B	The relative time between measurements
C	Relative quality of the data
D	Frequency order of the measurements

17. - E4C01

What is an effect of excessive phase noise in the local oscillator section of a receiver?

Select	Answer
A	It can cause strong signals on nearby frequencies to interfere with reception of weak signals
B	It reduces receiver sensitivity
C	It decreases receiver third-order intermodulation distortion dynamic range
D	It limits the receiver's ability to receive strong signals

18. - E4D10

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

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

19. - E4E08

What type of signal is picked up by electrical wiring near a radio antenna?

Select	Answer
A	A differential-mode signal at the AC power line frequency
B	A common-mode signal at the frequency of the radio transmitter
C	Harmonics of the AC power line frequency
D	An electrical-sparking signal

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

21. - E5B05

What happens to the magnitude of a reactance when it is converted to a susceptance?

Select	Answer
A	It is shifted by 90 degrees
B	The magnitude of the susceptance is the reciprocal of the magnitude of the reactance
C	It is unchanged
D	The sign is reversed

22. - E5C04

Which of the following represents a capacitive reactance in polar coordinates?

Select	Answer
A	A negative real part
B	A positive real part
C	A positive phase angle
D	A negative phase angle

23. - E5D15

What is the power factor of an R-L circuit having a 45 degree phase angle between the voltage and the current?

Select	Answer
A	0.866
B	1.0
C	0.707
D	0.5

24. - E6A08

What term indicates the frequency at which the grounded-base current gain of a transistor has decreased to 0.7 of the gain obtainable at 1 kHz?

Select	Answer
A	Alpha cutoff frequency
B	Corner frequency
C	Alpha rejection frequency
D	Beta cutoff frequency

25. - E6B11

What is used to control the attenuation of RF signals by a PIN diode?

Select	Answer
A	A sub-harmonic pump signal
B	Capacitance of an RF coupling capacitor
C	Forward DC bias current
D	Reverse voltage larger than the RF signal

26. - E6C04

What is the primary advantage of tri-state logic?

Select	Answer
A	More efficient arithmetic operations
B	Low power consumption
C	Ability to connect many device outputs to a common bus
D	High speed operation

27. - E6D13

What is the primary cause of inductor self-resonance?

Select	Answer
A	Inter-turn capacitance
B	The skin effect
C	Inductive kickback
D	Non-linear core hysteresis

28. - E6E11

What is a characteristic of DIP packaging used for integrated circuits?

Select	Answer
A	A total of two rows of connecting pins placed on opposite sides of the package (Dual In-line Package)
B	Low leakage doubly insulated package
C	Two chips in each package (Dual In Package)
D	Package mounts in a direct inverted position

29. - E6F05

Which describes an optical shaft encoder?

Select	Answer
A	A device which measures the strength of a beam of light using analog to digital conversion
B	A device which detects rotation of a control by interrupting a light source with a patterned wheel
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. - E7A04

How many flip-flops are required to divide a signal frequency by 4?

Select	Answer
A	2
B	8
C	4
D	1

31. - E7B17

Why are odd-order rather than even-order intermodulation distortion products of concern in linear power amplifiers?

Select	Answer
A	Because they maintain the sidebands, thus causing multiple duplicate signals
B	Because they invert the sidebands causing distortion
C	Because they are relatively far in frequency from the desired signal
D	Because they are relatively close in frequency to the desired signal

32. - E7C14

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

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

33. - E7D03

What device is typically used as a stable reference voltage in a linear voltage regulator?

Select	Answer
A	A Zener diode
B	An SCR
C	A tunnel diode
D	A varactor diode

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 two input frequencies along with their sum and difference frequencies
C	The sum, difference and square root of the input frequencies
D	1.414 and 0.707 times the input frequency

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. - 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	38
C	76
D	0.03

37. - E7H15

Which of these functions can be performed by a phase-locked loop?

Select	Answer
A	Comparison of two digital input signals, digital pulse counter
B	Photovoltaic conversion, optical coupling
C	Frequency synthesis, FM demodulation
D	Wide-band AF and RF power amplification

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. - 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	FM compressibility
B	Modulation index
C	Percentage of modulation
D	Quieting index

40. - E8C10

What is an advantage of Gray code in digital communications where symbols are transmitted as multiple bits

Select	Answer
A	It has more possible states than simple binary
B	It increases security
C	It has more resolution than simple binary
D	It facilitates error detection

41. - E8D01

Why are received spread spectrum signals resistant to interference?

Select	Answer
A	The high power used by a spread spectrum transmitter keeps its signal from being easily overpowered
B	The receiver is always equipped with a digital blanker
C	Signals not using the spread spectrum algorithm are suppressed in the receiver
D	If interference is detected by the receiver it will signal the transmitter to change frequencies

42. - E9A09

How is antenna efficiency calculated?

Select	Answer
A	(radiation resistance / transmission resistance) x 100 per cent
B	(total resistance / radiation resistance) x 100 per cent
C	(effective radiated power / transmitter output) x 100 percent
D	(radiation resistance / total resistance) x 100 per cent

43. - E9B01

In the antenna radiation pattern shown in Figure E9-1, what is the 3 dB beam-width?

Select	Answer
A	75 degrees
B	25 degrees
C	50 degrees
D	30 degrees

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

45. - E9D13

What usually occurs if a Yagi antenna is designed solely for maximum forward gain?

Select	Answer
A	The frequency response is widened over the whole frequency band
B	The SWR is reduced
C	The front-to-back ratio decreases
D	The front-to-back ratio increases

46. - E9E03

What is the name of the matching system that uses a section of transmission line connected in parallel with the feed line at or near the feed point?

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

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	The same as the characteristic impedance of the line
C	Very low impedance
D	The same as the output impedance of the generator

48. - E9G04

What are the two families of circles and arcs that make up a Smith chart?

Select	Answer
A	Voltage and impedance
B	Resistance and voltage
C	Resistance and reactance
D	Reactance and voltage

49. - E9H08

What is the function of a sense antenna?

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

50. - E0A04

When evaluating a site with multiple transmitters operating at the same time, the operators and licensees of which transmitters are responsible for mitigating over-exposure situations?

Select	Answer
A	Each transmitter operating with a duty-cycle greater than 50 percent
B	Each transmitter that produces 5 percent or more of its MPE limit at accessible locations
C	Only the most powerful transmitter
D	Only commercial transmitters

Figure E7-4

Figure E9-1