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

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1. - E1A12

With your transceiver displaying the carrier frequency of CW signals, you hear a DX station's CQ on 3.500 MHz. Is it legal to return the call using CW on the same frequency?

Select	Answer
A	No, U.S. stations are not permitted to use CW emissions below 3.525 MHz
B	No, one of the sidebands of the CW signal will be out of the band
C	Yes, the displayed frequency is within the 80 meter CW band segment
D	Yes, the DX station initiated the contact

2. - E1B09

Which amateur stations may be operated under RACES rules?

Select	Answer
A	Any FCC-licensed amateur station certified by the responsible civil defense organization for the area served
B	Any FCC-licensed amateur station participating in the Military Auxiliary Radio System (MARS)
C	Only those club stations licensed to Amateur Extra class operators
D	Any FCC-licensed amateur station except a Technician class

3. - E1C01

What is a remotely controlled station?

Select	Answer
A	A station operated away from its regular home location
B	A station controlled by someone other than the licensee
C	A station operating under automatic control
D	A station controlled indirectly through a control link

4. - E1D06

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

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

5. - E1E07

What should a VE do if a candidate fails to comply with the examiner's instructions during an amateur operator license examination?

Select	Answer
A	Allow the candidate to complete the examination, but invalidate the results
B	Immediately terminate everyone's examination and close the session
C	Immediately terminate the candidate's examination
D	Warn the candidate that continued failure to comply will result in termination of the examination

6. - E1F12

Who may be the control operator of an auxiliary station?

Select	Answer
A	Only General, Advanced or Amateur Extra Class operators
B	Only Technician, General, Advanced or Amateur Extra Class operators
C	Any licensed amateur operator
D	Only Amateur Extra Class operators

7. - E2A11

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

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

8. - E2B12

How are analog SSTV images typically transmitted on the HF bands?

Select	Answer
A	Video is converted to equivalent ASCII representation
B	Video is converted to equivalent Baudot representation
C	Varying tone frequencies representing the video are transmitted using PSK
D	Varying tone frequencies representing the video are transmitted using single sideband

9. - E2C13

What indicator is required to be used by U.S.-licensed operators when operating a station via remote control where the transmitter is located in the U.S.?

Select	Answer
A	/R# where # is the district of the remote station
B	/ followed by the USPS two letter abbreviation for the state in which the remote station is located
C	The ARRL section of the remote station
D	No additional indicator is required

10. - E2D14

What is one advantage of using JT65 coding?

Select	Answer
A	Easily copied by ear if necessary
B	Permits fast-scan TV transmissions over narrow bandwidth
C	The ability to decode signals which have a very low signal to noise ratio
D	Uses only a 65 Hz bandwidth

11. - E2E01

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

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

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	A low sunspot level combined with tropospheric ducting
C	Meteor showers concentrated in the extreme northern and southern latitudes
D	The interaction in the F2 layer between the solar wind and the Van Allen belt

13. - E3B05

Which amateur bands typically support long-path propagation?

Select	Answer
A	30 meters to 10 meters
B	160 meters to 40 meters
C	6 meters to 2 meters
D	160 meters to 10 meters

14. - E3C10

What does the 304A solar parameter measure?

Select	Answer
A	UV emissions at 304 angstroms, correlated to solar flux index
B	The ratio of X-Ray flux to radio flux, correlated to sunspot number
C	The solar emission at 304 GHz, correlated to X-Ray flare levels
D	The solar wind velocity at 304 degrees from the solar equator, correlated to solar activity

15. - E4A12

Which of the following procedures is an important precaution to follow when connecting a spectrum analyzer to a transmitter output?

Select	Answer
A	Match the antenna to the load
B	All of these choices are correct
C	Attenuate the transmitter output going to the spectrum analyzer
D	Use high quality double shielded coaxial cables to reduce signal losses

16. - E4B06

How much power is being absorbed by the load when a directional power meter connected between a transmitter and a terminating load reads 100 watts forward power and 25 watts reflected power?

Select	Answer
A	25 watts
B	125 watts
C	75 watts
D	100 watts

17. - E4C16

Which of the following is caused by missing codes in an SDR receiver's analog-to-digital converter?

Select	Answer
A	Overload
B	Excess output level
C	Distortion
D	Loss of sensitivity

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 1 mW input signals will produce a third-order intermodulation product which is 40 dB stronger than the input signal
C	A pair of 40 dBm signals will theoretically generate a third-order intermodulation product with the same level as the input signals
D	The receiver can tolerate signals up to 40 dB above the noise floor without producing third-order intermodulation products

19. - E4E04

How can conducted and radiated noise caused by an automobile alternator be suppressed?

Select	Answer
A	By installing filter capacitors in series with the DC power lead and a blocking capacitor in the field lead
B	By installing a noise suppression resistor and a blocking capacitor in both leads
C	By connecting the radio's power leads directly to the battery and by installing coaxial capacitors in line with the alternator leads
D	By installing a high-pass filter in series with the radio's power lead and a low-pass filter in parallel with the field lead

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	Reactance of either the inductance or capacitance times the resistance
C	Reactance of the inductance times the reactance of the capacitance
D	Resistance divided by the reactance of either the inductance or capacitance

21. - E5B06

What is susceptance?

Select	Answer
A	A measure of the efficiency of a transformer
B	The inverse of reactance
C	The magnetic impedance of a circuit
D	The ratio of magnetic field to electric field

22. - E5C03

Which of the following represents an inductive reactance in polar coordinates?

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

23. - E5D03

What is microstrip?

Select	Answer
A	Lightweight transmission line made of common zip cord
B	Short lengths of coax mounted on printed circuit boards to minimize time delay between microwave circuits
C	Miniature coax used for low power applications
D	Precision printed circuit conductors above a ground plane that provide constant impedance interconnects at microwave frequencies

24. - E6A13

What do the initials CMOS stand for?

Select	Answer
A	Complementary Mica-Oxide Silicon
B	Complementary Metal-Oxide Semiconductor
C	Common Mode Oscillating System
D	Common Mode Organic Silicon

25. - E6B10

In Figure E6-3, what is the schematic symbol for a light-emitting diode?

Select	Answer
A	7
B	6
C	5
D	1

26. - E6C04

What is the primary advantage of tri-state logic?

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

27. - E6D13

What is the primary cause of inductor self-resonance?

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

28. - E6E09

Which of the following component package types would be most suitable for use at frequencies above the HF range?

Select	Answer
A	TO-220
B	Surface mount
C	Axial lead
D	Radial lead

29. - E6F03

What is the most common configuration of an optoisolator or optocoupler?

Select	Answer
A	A frequency modulated helium-neon laser
B	An amplitude modulated helium-neon laser
C	A lens and a photomultiplier
D	An LED and a phototransistor

30. - E7A03

Which of the following can divide the frequency of a pulse train by 2?

Select	Answer
A	A flip-flop
B	An OR gate
C	An XOR gate
D	A multiplexer

31. - E7B04

Where on the load line of a Class A common emitter amplifier would bias normally be set?

Select	Answer
A	Approximately half-way between saturation and cutoff
B	At a point where the load line intersects the zero bias current curve
C	Where the load line intersects the voltage axis
D	At a point where the bias resistor equals the load resistor

32. - E7C13

What is one advantage of a Pi-matching network over an L-matching network consisting of a single inductor and a single capacitor?

Select	Answer
A	L-networks cannot perform impedance transformation
B	The Q of Pi-networks can be varied depending on the component values chosen
C	Pi-networks are designed for balanced input and output
D	Pi-networks have fewer components

33. - E7D08

What type of circuit is shown in Figure E7-3?

Select	Answer
A	Switching voltage regulator
B	Emitter follower
C	Grounded emitter amplifier
D	Linear voltage regulator

34. - E7E01

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

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

35. - E7F07

What function can a Fast Fourier Transform perform?

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

36. - E7G01

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

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

37. - E7H07

How can an oscillator's microphonic responses be reduced?

Select	Answer
A	Use of NP0 capacitors
B	Using the oscillator only for CW and digital signals
C	Mechanically isolating the oscillator circuitry from its enclosure
D	Eliminating noise on the oscillator's power supply

38. - E8A01

What is the name of the process that shows that a square wave is made up of a sine wave plus all of its odd harmonics?

Select	Answer
A	Differential analysis
B	Vector analysis
C	Numerical analysis
D	Fourier analysis

39. - E8B07

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

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

40. - E8C11

What is the relationship between symbol rate and baud?

Select	Answer
A	Baud is only used for RTTY
B	Symbol rate is only used for packet-based modes
C	Baud is twice the symbol rate
D	They are the same

41. - E8D05

What is the most common method of reducing key clicks?

Select	Answer
A	High-pass filters at the transmitter output
B	Increase keying waveform rise and fall times
C	Reduce keying waveform rise and fall times
D	Low-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 match impedances in order to minimize standing wave ratio on the transmission line
C	To measure the near-field radiation density from a transmitting antenna
D	To calculate the front-to-side ratio of the antenna

43. - E9B10

What is the principle of a Method of Moments analysis?

Select	Answer
A	A wire is modeled as a single sine-wave current generator
B	A wire is modeled as a series of segments, each having a distinct value of voltage across it
C	A wire is modeled as a series of segments, each having a uniform value of current
D	A wire is modeled as a series of points, each having a distinct location in space

44. - E9C14

How does the performance of a horizontally polarized antenna mounted on the side of a hill compare with the same antenna mounted on flat ground?

Select	Answer
A	The main lobe takeoff angle increases in the downhill direction
B	The main lobe takeoff angle decreases in the downhill direction
C	The horizontal beam width decreases in the downhill direction
D	The horizontal beam width increases in the uphill direction

45. - E9D10

What happens to feed point impedance at the base of a fixed length HF mobile antenna as the frequency of operation is lowered?

Select	Answer
A	The radiation resistance increases and the capacitive reactance increases
B	The radiation resistance decreases and the capacitive reactance decreases
C	The radiation resistance increases and the capacitive reactance decreases
D	The radiation resistance decreases and the capacitive reactance increases

46. - E9E06

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

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

47. - E9F13

What impedance does a 1/4 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 transmission line
C	Very low impedance
D	The same as the generator output impedance

48. - E9G05

What type of chart is shown in Figure E9-3?

Select	Answer
A	Free space radiation directivity chart
B	Elevation angle radiation pattern chart
C	Azimuth angle radiation pattern chart
D	Smith chart

49. - E9H07

Why is it advisable to use an RF attenuator on a receiver being used for direction finding?

Select	Answer
A	It narrows the bandwidth of the received signal to improve signal to noise ratio
B	It compensates for the effects of an isotropic antenna, thereby improving directivity
C	It reduces loss of received signals caused by antenna pattern nulls, thereby increasing sensitivity
D	It prevents receiver overload which could make it difficult to determine peaks or nulls

50. - E0A09

Which insulating material commonly used as a thermal conductor for some types of electronic devices is extremely toxic if broken or crushed and the particles are accidentally inhaled?

Select	Answer
A	Zinc oxide
B	Beryllium Oxide
C	Mica
D	Uranium Hexafluoride

Figure E6-3

Figure E7-3

Figure E9-3