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

Logging in (or registering) will help the system to select questions that you need to focus on.

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	The exact lower band edge
B	1 kHz above the lower band edge
C	300 Hz 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	Any transmitted signal that unintentionally interferes with another licensed radio station
B	An amateur station transmission made at random without the proper call sign identification
C	An emission outside its necessary bandwidth that can be reduced or eliminated without affecting the information transmitted
D	A signal transmitted to prevent its detection by any station other than the intended recipient

3. - E1C02

What is meant by automatic control of a station?

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

4. - E1D09

Which UHF amateur service bands have frequencies available for a space station?

Select	Answer
A	33 cm and 13 cm
B	70 cm and 13 cm
C	70 cm and 33 cm
D	70 cm only

5. - E1E06

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

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

6. - E1F05

Amateur stations may not transmit in which of the following frequency segments if they are located in the contiguous 48 states and north of Line A?

Select	Answer
A	440 MHz - 450 MHz
B	53 MHz - 54 MHz
C	420 MHz - 430 MHz
D	222 MHz - 223 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	A linearly polarized antenna
C	A circularly polarized antenna
D	An isotropic antenna

8. - E2B01

How many times per second is a new frame transmitted in a fast-scan (NTSC) television system?

Select	Answer
A	30
B	120
C	90
D	60

9. - E2C04

What type of transmission is most often used for a ham radio mesh network?

Select	Answer
A	Multiple Frequency Shift Keying in the 10 GHz band
B	Frequency division multiplex in the 24 GHz band
C	Spread spectrum in the 2.4 GHz band
D	Store and forward on the 440 MHz band

10. - E2D03

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

Select	Answer
A	Olivia
B	JT65
C	PACTOR III
D	FSK441

11. - E2E04

What is indicated when one of the ellipses in an FSK crossed-ellipse display suddenly disappears?

Select	Answer
A	The mark and space signal have been inverted
B	One of the signal filters is saturated
C	Selective fading has occurred
D	The receiver has drifted 5 kHz from the desired receive frequency

12. - E3A02

What characterizes libration fading of an EME signal?

Select	Answer
A	A fluttery irregular fading
B	The returning echo is several Hertz lower in frequency than the transmitted signal
C	A gradual loss of signal as the Sun rises
D	A slow change in the pitch of the CW signal

13. - E3B02

What is the approximate maximum range for signals using transequatorial propagation?

Select	Answer
A	5000 miles
B	7500 miles
C	2500 miles
D	1000 miles

14. - E3C07

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

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

15. - E4A09

When using a computer's soundcard input to digitize signals, what is the highest frequency signal that can be digitized without aliasing?

Select	Answer
A	One-half the sample rate
B	The same as the sample rate
C	It depends on how the data is stored internally
D	One-tenth the sample rate

16. - E4B04

If a frequency counter with a specified accuracy of +/- 0.1 ppm reads 146,520,000 Hz, what is the most the actual frequency being measured could differ from the reading?

Select	Answer
A	1.4652 Hz
B	0.1 MHz
C	1.4652 kHz
D	14.652 Hz

17. - E4C02

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

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

18. - E4D02

Which of the following describes two problems caused by poor dynamic range in a communications receiver?

Select	Answer
A	Cross-modulation of the desired signal and insufficient audio power to operate the speaker
B	Oscillator instability and severe audio distortion of all but the strongest received signals
C	Oscillator instability requiring frequent retuning and loss of ability to recover the opposite sideband
D	Cross-modulation of the desired signal and desensitization from strong adjacent signals

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. - E5A16

What is the resonant frequency of a parallel RLC circuit if R is 33 ohms, L is 50 microhenrys and C is 10 picofarads?

Select	Answer
A	23.5 MHz
B	7.12 kHz
C	23.5 kHz
D	7.12 MHz

21. - E5B02

What is the term for the time it takes for a charged capacitor in an RC circuit to discharge to 36.8% of its initial voltage?

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

22. - E5C05

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

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

23. - E5D01

What is the result of skin effect?

Select	Answer
A	Thermal effects on the surface of the conductor increase the impedance
B	As frequency decreases, RF current flows in a thinner layer of the conductor, closer to the surface
C	As frequency increases, RF current flows in a thinner layer of the conductor, closer to the surface
D	Thermal effects on the surface of the conductor decrease the impedance

24. - E6A09

What is a depletion-mode FET?

Select	Answer
A	Any FET without a channel
B	An FET that exhibits a current flow between source and drain when no gate voltage is applied
C	An FET that has no current flow between source and drain when no gate voltage is applied
D	Any FET for which holes are the majority carriers

25. - E6B07

What is the failure mechanism when a junction diode fails due to excessive current?

Select	Answer
A	Charge carrier depletion
B	Excessive inverse voltage
C	Excessive junction temperature
D	Insufficient forward voltage

26. - E6C14

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

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

27. - E6D09

What devices are commonly used as VHF and UHF parasitic suppressors at the input and output terminals of a transistor HF amplifier?

Select	Answer
A	Ferrite beads
B	Electrolytic capacitors
C	Steel-core toroids
D	Butterworth filters

28. - E6E06

What characteristics of the MMIC make it a popular choice for VHF through microwave circuits?

Select	Answer
A	The ability to retrieve information from a single signal even in the presence of other strong signals
B	Nearly infinite gain, very high input impedance, and very low output impedance
C	Controlled gain, low noise figure, and constant input and output impedance over the specified frequency range
D	Plate current that is controlled by a control grid

29. - E6F01

What is photoconductivity?

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

30. - E7A10

What is a truth table?

Select	Answer
A	A diagram showing logic states when the digital device output is true
B	A table of logic symbols that indicate the logic states of an op-amp
C	A list of inputs and corresponding outputs for a digital device
D	A table of logic symbols that indicate the high logic states of an op-amp

31. - E7B18

What is a characteristic of a grounded-grid amplifier?

Select	Answer
A	High power gain
B	High filament voltage
C	Low bandwidth
D	Low input impedance

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

33. - E7D15

What is the purpose of a "step-start" circuit in a high voltage power supply?

Select	Answer
A	To allow for remote control of the power supply
B	To compensate for variations of the incoming line voltage
C	To provide a dual-voltage output for reduced power applications
D	To allow the filter capacitors to charge gradually

34. - E7E12

What is a frequency discriminator stage in a FM receiver?

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

35. - E7F07

What function can a Fast Fourier Transform perform?

Select	Answer
A	Converting analog signals to digital form
B	Converting digital signals from the time domain to the frequency domain
C	Converting 8-bit data to 16 bit data
D	Converting digital signals to analog form

36. - E7G01

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

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

37. - E7H15

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

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

38. - E8A10

What is the purpose of a low pass filter used in conjunction with a digital-to-analog converter?

Select	Answer
A	Remove harmonics from the output caused by the discrete analog levels generated
B	Lower the input bandwidth to increase the effective resolution
C	Improve accuracy by removing out of sequence codes from the input
D	All of these choices are correct

39. - E8B04

What is the modulation index of an FM-phone signal having a maximum carrier deviation of plus or minus 6 kHz when modulated with a 2 kHz modulating frequency?

Select	Answer
A	6000
B	3
C	2000
D	1/3

40. - E8C08

How does ARQ accomplish error correction?

Select	Answer
A	Special polynomial codes provide automatic correction
B	If errors are detected, a retransmission is requested
C	If errors are detected, redundant data is substituted
D	Special binary codes provide automatic correction

41. - E8D12

What is the advantage of including a parity bit with an ASCII character stream?

Select	Answer
A	Faster transmission rate
B	The signal can overpower interfering signals
C	Some types of errors can be detected SUBELEMENT E9 - ANTENNAS AND TRANSMISSION LINES [8 Exam Questions - 8 Groups] E9A Basic Antenna parameters: radiation resistance, gain, beamwidth, efficiency, beamwidth; effective radiated power, polarization E9A01 (C) What describes an isotropic antenna? A. A grounded antenna used to measure earth conductivity B. A horizontally polarized antenna used to compare Yagi antennas C. A theoretical antenna used as a reference for antenna gain D. A spacecraft antenna used to direct signals toward the earth
D	Foreign language characters can be sent

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. - E9B16

How many elevation lobes appear in the forward direction of the antenna radiation pattern shown in Figure E9-2?

Select	Answer
A	1
B	4
C	7
D	3

44. - E9C11

How is the far-field elevation pattern of a vertically polarized antenna affected by being mounted over seawater versus rocky ground?

Select	Answer
A	Both the high-angle and low-angle radiation decrease
B	The high-angle radiation increases
C	The low-angle radiation increases
D	The low-angle radiation decreases

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 swamp out harmonics
D	To minimize losses

46. - E9E06

What is the equivalent lumped-constant network for a hairpin matching system of a 3-element Yagi?

Select	Answer
A	Pi-network
B	Pi-L-network
C	A shunt inductor
D	A series capacitor

47. - E9F16

Which of the following is a significant difference between foam dielectric coaxial cable and solid dielectric cable, assuming all other parameters are the same?

Select	Answer
A	Foam dielectric has lower safe operating voltage limits
B	Foam dielectric has higher velocity factor
C	All of these choices are correct
D	Foam dielectric has lower loss per unit of length

48. - E9G06

On the Smith chart shown in Figure E9-3, what is the name for the large outer circle on which the reactance arcs terminate?

Select	Answer
A	Polar axis
B	Impedance axis
C	Prime axis
D	Reactance axis

49. - E9H05

What is the main drawback of a wire-loop antenna for direction finding?

Select	Answer
A	It is non-rotatable
B	It is practical for use only on VHF bands
C	It receives equally well in all directions
D	It has a bidirectional pattern

50. - E0A01

What is the primary function of an external earth connection or ground rod?

Select	Answer
A	Reduce received noise
B	Reduce RF current flow between pieces of equipment
C	Reduce RFI to telephones and home entertainment systems
D	Lightning protection

Figure E9-2

Figure E9-3