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

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1. - E1A02

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

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

2. - E1B01

Which of the following constitutes a spurious emission?

Select	Answer
A	A signal transmitted to prevent its detection by any station other than the intended recipient
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	An emission outside its necessary bandwidth that can be reduced or eliminated without affecting the information transmitted

3. - E1C04

What is meant by IARP?

Select	Answer
A	A forecast of intermittent aurora radio propagation
B	An international amateur radio permit that allows U.S. amateurs to operate in certain countries of the Americas
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 stations on Earth satellites for public service broadcast
B	A radio communications service using amateur radio stations on satellites
C	A spacecraft launching service for amateur-built satellites
D	A radio navigation service using satellites for the purpose of self training, intercommunication and technical studies carried out by amateurs

5. - E1E12

What must the VE team do with the application form if the examinee does not pass the exam?

Select	Answer
A	Maintain the application form with the VEC's records
B	Send the application form to the FCC and inform the FCC of the grade
C	Return the application document to the examinee
D	Destroy the application form

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. - E2A05

What do the letters in a satellite's mode designator specify?

Select	Answer
A	The uplink and downlink frequency ranges
B	Power limits for uplink and downlink transmissions
C	The location of the ground control station
D	The polarization of uplink and downlink signals

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 lines from left to right in one field and right to left in the next
C	By scanning each field from bottom to top
D	By scanning odd numbered lines in one field and even numbered lines in the next

9. - E2C09

What type of equipment is commonly used to implement a ham radio mesh network?

Select	Answer
A	A standard wireless router running custom software
B	An optical cable connection between the USB ports of 2 separate computers
C	A 2 meter VHF transceiver with a 1200 baud modem
D	A 440 MHz transceiver with a 9600 baud modem

10. - E2D09

Which of these digital modes has the fastest data throughput under clear communication conditions?

Select	Answer
A	PSK31
B	170 Hz shift, 45 baud RTTY
C	AMTOR
D	300 baud packet

11. - E2E05

Which type of digital mode does not support keyboard-to-keyboard operation?

Select	Answer
A	PSK31
B	RTTY
C	MFSK
D	Winlink

12. - E3A12

What is the cause of auroral activity?

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

13. - E3B07

Which of the following could account for hearing an echo on the received signal of a distant station?

Select	Answer
A	High D layer absorption
B	Transmit frequency is higher than the MUF
C	Receipt of a signal by more than one path
D	Meteor scatter

14. - E3C07

Which of the following descriptors indicates the greatest solar flare intensity?

Select	Answer
A	Class B
B	Class X
C	Class A
D	Class M

15. - E4A15

What is an advantage of a period-measuring frequency counter over a direct-count type?

Select	Answer
A	It can directly measure the modulation index of an FM transmitter
B	It provides improved resolution of low-frequency signals within a comparable time period
C	It does not require an expensive high-precision time base
D	It can run on battery power for remote measurements

16. - E4B11

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

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

17. - E4C02

Which of the following portions of a receiver can be effective in eliminating image signal interference?

Select	Answer
A	A narrow IF filter
B	A notch filter
C	A properly adjusted product detector
D	A front-end filter or pre-selector

18. - E4D13

Which of the following can cause receiver desensitization?

Select	Answer
A	Audio gain adjusted too low
B	Strong adjacent channel signals
C	Audio bias adjusted too high
D	Squelch gain misadjusted

19. - E4E14

What is one type of electrical interference that might be caused by the operation of a nearby personal computer?

Select	Answer
A	A loud AC hum in the audio output of your station receiver
B	A clicking noise at intervals of a few seconds
C	The appearance of unstable modulated or unmodulated signals at specific frequencies
D	A whining type noise that continually pulses off and on

20. - E5A03

What is the magnitude of the impedance of a series RLC circuit at resonance?

Select	Answer
A	Approximately equal to circuit resistance
B	High, as compared to the circuit resistance
C	Approximately equal to capacitive reactance
D	Approximately equal to inductive reactance

21. - E5B09

What is the relationship between the current through a capacitor and the voltage across a capacitor?

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

22. - E5C14

Which point on Figure E5-2 best represents the impedance of a series circuit consisting of a 400 ohm resistor and a 38 picofarad capacitor at 14 MHz?

Select	Answer
A	Point 5
B	Point 6
C	Point 4
D	Point 2

23. - E5D04

Why are short connections necessary at microwave frequencies?

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

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 rejection frequency
B	Alpha cutoff frequency
C	Corner frequency
D	Beta cutoff frequency

25. - E6B05

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

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

26. - E6C14

What is the primary advantage of using a Programmable Gate Array (PGA) in a logic circuit?

Select	Answer
A	A PGA contains its own internal power supply
B	All of these choices are correct
C	Many similar gates are less expensive than a mixture of gate types
D	Complex logic functions can be created in a single integrated circuit

27. - E6D05

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

Select	Answer
A	Ferrite toroids generally require fewer turns to produce a given inductance value
B	Ferrite toroids generally have lower initial permeability
C	Ferrite toroids are easier to use with surface mount technology
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	-20 dBm
C	-10 dB
D	44 dBm

29. - E6F01

What is photoconductivity?

Select	Answer
A	The conversion of photon energy to electromotive energy
B	The decreased conductivity of an illuminated semiconductor
C	The increased conductivity of an illuminated semiconductor
D	The conversion of electromotive energy to photon energy

30. - E7A08

What logical operation does an OR gate perform?

Select	Answer
A	It produces logic "1" at its output if any or all inputs are logic "1"
B	It produces logic "0" at its output if all inputs are logic "1"
C	It only produces logic "0" at its output when all inputs are logic "1"
D	It produces logic "1" at its output if all inputs are logic "0"

31. - E7B02

What is a Class D amplifier?

Select	Answer
A	A low power amplifier that uses a differential amplifier for improved linearity
B	A type of amplifier that uses switching technology to achieve high efficiency
C	An amplifier that uses drift-mode FETs for high efficiency
D	A frequency doubling amplifier

32. - E7C03

What advantage does a Pi-L-network have over a regular Pi-network for impedance matching between the final amplifier of a vacuum-tube transmitter and an antenna?

Select	Answer
A	Higher efficiency
B	Lower losses
C	Greater harmonic suppression
D	Greater transformation range

33. - E7D02

What is one characteristic of a switching electronic voltage regulator?

Select	Answer
A	It is generally less efficient than a linear regulator
B	It gives a ramp voltage at its output
C	The resistance of a control element is varied in direct proportion to the line voltage or load current
D	The controlled device's duty cycle is changed to produce a constant average output voltage

34. - E7E01

Which of the following can be used to generate FM phone emissions?

Select	Answer
A	A reactance modulator on the final amplifier
B	A balanced modulator on the oscillator
C	A balanced modulator on the audio amplifier
D	A reactance modulator on the oscillator

35. - E7F08

What is the function of decimation with regard to digital filters?

Select	Answer
A	Removing unnecessary significant digits
B	Converting data to binary code decimal form
C	Reducing the effective sample rate by removing samples
D	Attenuating the signal

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	38
B	76
C	0.03
D	1

37. - E7H15

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

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

38. - E8A11

What type of information can be conveyed using digital waveforms?

Select	Answer
A	Video signals
B	Data
C	All of these choices are correct
D	Human speech

39. - E8B09

What is meant by deviation ratio?

Select	Answer
A	The ratio of the audio modulating frequency to the center carrier frequency
B	The ratio of the maximum carrier frequency deviation to the highest audio modulating frequency
C	The ratio of the carrier center frequency to the audio modulating frequency
D	The ratio of the highest audio modulating frequency to the average audio modulating frequency

40. - E8C06

What is the necessary bandwidth of a 170-hertz shift, 300-baud ASCII transmission?

Select	Answer
A	0.5 kHz
B	0.1 Hz
C	0.3 kHz
D	1.0 kHz

41. - E8D05

What is the most common method of reducing key clicks?

Select	Answer
A	Low-pass filters at the transmitter output
B	Reduce keying waveform rise and fall times
C	Increase keying waveform rise and fall times
D	High-pass filters at the transmitter output

42. - E9A03

Why would one need to know the feed point impedance of an antenna?

Select	Answer
A	To calculate the front-to-back ratio of the antenna
B	To measure the near-field radiation density from a transmitting antenna
C	To match impedances in order to minimize standing wave ratio on the transmission line
D	To calculate the front-to-side ratio of the antenna

43. - E9B04

What may occur when a directional antenna is operated at different frequencies within the band for which it was designed?

Select	Answer
A	The E-field and H-field patterns may reverse
B	Element spacing limits could be exceeded
C	Feed point impedance may become negative
D	The gain may change depending on frequency

44. - E9C10

Which of the following describes a Zepp antenna?

Select	Answer
A	An omni-directional antenna commonly used for satellite communications
B	A dipole constructed from zip cord
C	An end fed dipole antenna
D	A vertical array capable of quickly changing the direction of maximum radiation by changing phasing lines

45. - E9D04

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

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

46. - E9E10

Which of these choices is an effective way to match an antenna with a 100 ohm feed point impedance to a 50 ohm coaxial cable feed line?

Select	Answer
A	Connect 1/2 wavelength shorted stub of 75 ohm cable in parallel with the 50 ohm cable where it attaches to the antenna
B	Insert a 1/2 wavelength piece of 300 ohm twin-lead in series between the antenna terminals and the 50 ohm feed cable
C	Insert a 1/4-wavelength piece of 75 ohm coaxial cable transmission line in series between the antenna terminals and the 50 ohm feed cable
D	Connect a 1/4-wavelength open stub of 300 ohm twin-lead in parallel with the coaxial feed line where it connects to the antenna

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

48. - E9G09

What third family of circles is often added to a Smith chart during the process of solving problems?

Select	Answer
A	Antenna-length circles
B	Standing wave ratio circles
C	Radiation-pattern circles
D	Coaxial-length circles

49. - E9H10

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

Select	Answer
A	By reducing the permeability of the loop shield
B	By winding adjacent turns in opposing directions
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. - E0A05

What is one of the potential hazards of using microwaves in the amateur radio bands?

Select	Answer
A	The high gain antennas commonly used can result in high exposure levels
B	The extremely high frequency energy can damage the joints of antenna structures
C	Microwaves often travel long distances by ionospheric reflection
D	Microwaves are ionizing radiation

Figure E5-2

Figure E7-4