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

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1. - E1A01

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

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

2. - E1B03

Within what distance must an amateur station protect an FCC monitoring facility from harmful interference?

Select	Answer
A	30 miles
B	1 mile
C	10 miles
D	3 miles

3. - E1C11

Which of the following operating arrangements allows an FCC-licensed U.S. citizen to operate in many European countries, and alien amateurs from many European countries to operate in the U.S.?

Select	Answer
A	ITU reciprocal license
B	IARP agreement
C	CEPT agreement
D	All of these choices are correct

4. - E1D06

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

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

5. - E1E06

Who is responsible for the proper conduct and necessary supervision during an amateur operator license examination session?

Select	Answer
A	The VEC coordinating the session
B	The FCC
C	Each administering VE
D	The VE session manager

6. - E1F01

On what frequencies are spread spectrum transmissions permitted?

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

7. - E2A11

What type of antenna can be used to minimize the effects of spin modulation and Faraday rotation?

Select	Answer
A	A log-periodic dipole array
B	An isotropic antenna
C	A circularly polarized antenna
D	A linearly polarized antenna

8. - E2B17

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

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

9. - E2C09

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

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

10. - E2D12

How does JT65 improve EME communications?

Select	Answer
A	It can decode signals many dB below the noise floor using FEC
B	It controls the receiver to track Doppler shift
C	All of these choices are correct
D	It supplies signals to guide the antenna to track the Moon

11. - E2E01

Which type of modulation is common for data emissions below 30 MHz?

Select	Answer
A	Pulse modulation
B	DTMF tones modulating an FM signal
C	FSK
D	Spread spectrum

12. - E3A11

What is a typical range for tropospheric propagation of microwave signals?

Select	Answer
A	100 miles to 300 miles
B	10 miles to 50 miles
C	2500 miles
D	1200 miles

13. - E3B07

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

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

14. - E3C02

What is indicated by a rising A or K index?

Select	Answer
A	An increase in the critical frequency
B	Higher levels of solar UV radiation
C	Increasing disruption of the geomagnetic field
D	Decreasing disruption of the geomagnetic field

15. - E4A04

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

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

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

17. - E4C09

Which of the following choices is a good reason for selecting a high frequency for the design of the IF in a conventional HF or VHF communications receiver?

Select	Answer
A	Improved receiver noise figure
B	Fewer components in the receiver
C	Reduced drift
D	Easier for front-end circuitry to eliminate image responses

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. - E4E07

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

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

20. - E5A10

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

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

21. - E5B05

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

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

22. - E5C04

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

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

23. - E5D02

Why is it important to keep lead lengths short for components used in circuits for VHF and above?

Select	Answer
A	To increase the thermal time constant
B	All of these choices are correct
C	To avoid unwanted inductive reactance
D	To maintain component lifetime

24. - E6A17

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

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

25. - E6B04

What type of semiconductor device is designed for use as a voltage-controlled capacitor?

Select	Answer
A	Varactor diode
B	Tunnel diode
C	Silicon-controlled rectifier
D	Zener diode

26. - E6C06

Why do CMOS digital integrated circuits have high immunity to noise on the input signal or power supply?

Select	Answer
A	The input switching threshold is about two times the power supply voltage
B	The input switching threshold is about one-half the power supply voltage
C	Larger bypass capacitors are used in CMOS circuit design
D	Input signals are stronger

27. - E6D02

What is the equivalent circuit of a quartz crystal?

Select	Answer
A	Motional inductance and loss resistance in series, paralleled with motional capacitance and a capacitor representing electrode and stray capacitance
B	Motional capacitance, motional inductance, loss resistance, and a capacitor representing electrode and stray capacitance all in series
C	Motional capacitance, motional inductance, loss resistance, and a capacitor representing electrode and stray capacitance all in parallel
D	Motional capacitance, motional inductance, and loss resistance in series, all in parallel with a shunt capacitor representing electrode and stray capacitance

28. - E6E07

Which of the following is typically used to construct a MMIC-based microwave amplifier?

Select	Answer
A	Ground-plane construction
B	Wave-soldering construction
C	Microstrip construction
D	Point-to-point construction

29. - E6F10

What is the most common type of photovoltaic cell used for electrical power generation?

Select	Answer
A	Selenium
B	Silicon
C	Copper oxide
D	Cadmium Sulfide

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. - E7B11

In Figure E7-1, what is the purpose of R3?

Select	Answer
A	Output load resistor
B	Self bias
C	Fixed bias
D	Emitter bypass

32. - E7C07

What kind of filter would you use to attenuate an interfering carrier signal while receiving an SSB transmission?

Select	Answer
A	A notch filter
B	A Pi-network filter
C	A band-pass filter
D	An all-pass filter

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	Pass transistor
C	Error amplifier
D	Reference voltage

34. - E7E12

What is a frequency discriminator stage in a FM receiver?

Select	Answer
A	An FM generator circuit
B	A circuit for filtering two closely adjacent signals
C	A circuit for detecting FM signals
D	An automatic band-switching circuit

35. - E7F09

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

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

36. - E7G04

What is meant by the term op-amp input offset voltage?

Select	Answer
A	The potential between the amplifier input terminals of the op-amp in an open loop condition
B	The differential input voltage needed to bring the open loop output voltage to zero
C	The output voltage of the op-amp minus its input voltage
D	The difference between the output voltage of the op-amp and the input voltage required in the immediately following stage

37. - E7H12

Which of the following must be done to insure that a crystal oscillator provides the frequency specified by the crystal manufacturer?

Select	Answer
A	Bias the crystal at a specified current
B	Provide the crystal with a specified parallel capacitance
C	Bias the crystal at a specified voltage
D	Provide the crystal with a specified parallel inductance

38. - E8A08

Why would a direct or flash conversion analog-to-digital converter be useful for a software defined radio?

Select	Answer
A	Immunity to out of sequence coding reduces spurious responses
B	Very low power consumption decreases frequency drift
C	Very high speed allows digitizing high frequencies
D	All of these choices are correct

39. - E8B07

Orthogonal Frequency Division Multiplexing is a technique used for which type of amateur communication?

Select	Answer
A	High speed digital modes
B	Extremely low-power contacts
C	OFDM signals are not allowed on amateur bands
D	EME

40. - E8C01

How is Forward Error Correction implemented?

Select	Answer
A	By varying the frequency shift of the transmitted signal according to a predefined algorithm
B	By the receiving station repeating each block of three data characters
C	By transmitting extra data that may be used to detect and correct transmission errors
D	By transmitting a special algorithm to the receiving station along with the data characters

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	Frequency hopping
B	Direct sequence
C	Phase compandored spread spectrum
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	63.2 watts
C	159 watts
D	252 watts

43. - E9B14

What type of information can be obtained by submitting the details of a proposed new antenna to a modeling program?

Select	Answer
A	SWR vs frequency charts
B	Antenna gain
C	All of these choices are correct
D	Polar plots of the far field elevation and azimuth patterns

44. - E9C08

What is a folded dipole antenna?

Select	Answer
A	A dipole one-quarter wavelength long
B	A dipole configured to provide forward gain
C	A type of ground-plane antenna
D	A dipole consisting of one wavelength of wire forming a very thin loop

45. - E9D12

Which of the following would provide the best RF ground for your station?

Select	Answer
A	A 50 ohm resistor connected to ground
B	An electrically short connection to a metal water pipe
C	An electrically short connection to 3 or 4 interconnected ground rods via a series RF choke
D	An electrically short connection to 3 or 4 interconnected ground rods driven into the Earth

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 delta match
D	The gamma match

47. - E9F15

What impedance does a 1/2 wavelength transmission line present to a generator when the line is open at the far end?

Select	Answer
A	Very high impedance
B	The same as the output impedance of the generator
C	Very low impedance
D	The same as the characteristic impedance of the line

48. - E9G07

On the Smith chart shown in Figure E9-3, what is the only straight line shown?

Select	Answer
A	The current axis
B	The voltage axis
C	The resistance axis
D	The reactance axis

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 increasing either the number of wire turns in the loop or the area of the loop structure or both
C	By increasing the number of wire turns in the loop and reducing the area of the loop structure
D	By winding adjacent turns in opposing directions

50. - E0A10

What toxic material may be present in some electronic components such as high voltage capacitors and transformers?

Select	Answer
A	Polychlorinated Biphenyls
B	Polytetrafluroethylene
C	Polyethylene
D	Polymorphic silicon

Figure E7-1

Figure E9-3