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. - E1A08

If a station in a message forwarding system inadvertently forwards a message that is in violation of FCC rules, who is primarily accountable for the rules violation?

Select	Answer
A	The control operator of the originating station
B	The control operators of all the stations in the system
C	The control operator of the packet bulletin board station
D	The control operators of all the stations in the system not authenticating the source from which they accept communications

2. - E1B01

Which of the following constitutes a spurious emission?

Select	Answer
A	An amateur station transmission made at random without the proper call sign identification
B	A signal transmitted to prevent its detection by any station other than the intended recipient
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. - E1C08

What is the maximum permissible duration of a remotely controlled station's transmissions if its control link malfunctions?

Select	Answer
A	3 minutes
B	30 seconds
C	10 minutes
D	5 minutes

4. - E1D10

Which amateur stations are eligible to be telecommand stations?

Select	Answer
A	Any amateur station designated by NASA
B	All of these choices are correct
C	Any amateur station so designated by the space station licensee, subject to the privileges of the class of operator license held by the control operator
D	Any amateur station so designated by the ITU

5. - E1E13

Which of these choices is an acceptable method for monitoring the applicants if a VEC opts to conduct an exam session remotely?

Select	Answer
A	The exam proctor observes the applicants and reports any violations
B	Use a real-time video link and the Internet to connect the exam session to the observing VEs
C	Have each applicant sign an affidavit stating that all session rules were followed
D	Record the exam session on video tape for later review by the VE team

6. - E1F09

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

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

7. - E2A01

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

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

8. - E2B09

What hardware, other than a receiver with SSB capability and a suitable computer, is needed to decode SSTV using Digital Radio Mondiale (DRM)?

Select	Answer
A	No other hardware is needed
B	A special IF converter
C	A special notch filter to remove synchronization pulses
D	A special front end limiter

9. - E2C05

What is the function of a DX QSL Manager?

Select	Answer
A	To allocate frequencies for DXpeditions
B	To relay calls to and from a DX station
C	To handle the receiving and sending of confirmation cards for a DX station
D	To run a net to allow many stations to contact a rare DX station

10. - E2D05

Which of the following techniques is normally used by low Earth orbiting digital satellites to relay messages around the world?

Select	Answer
A	Digipeating
B	Store-and-forward
C	Multi-satellite relaying
D	Node hopping

11. - E2E12

Which type of control is used by stations using the Automatic Link Enable (ALE) protocol?

Select	Answer
A	Local
B	Remote
C	Automatic
D	ALE can use any type of control

12. - E3A17

What is meant by circularly polarized electromagnetic waves?

Select	Answer
A	Waves with an electric field bent into a circular shape
B	Waves that circle the Earth
C	Waves produced by a loop antenna
D	Waves with a rotating electric field

13. - E3B13

Why is chordal hop propagation desirable?

Select	Answer
A	The signal experiences less loss along the path compared to normal skip propagation
B	The MUF for chordal hop propagation is much lower than for normal skip propagation
C	Signals travel faster along ionospheric chords
D	Atmospheric noise is lower in the direction of chordal hop propagation

14. - E3C04

What does the value of Bz (B sub Z) represent?

Select	Answer
A	Direction and strength of the interplanetary magnetic field
B	Duration of long-delayed echoes
C	Geomagnetic field stability
D	Critical frequency for vertical transmissions

15. - E4A05

What might be an advantage of a digital vs an analog oscilloscope?

Select	Answer
A	Storage of traces for future reference
B	All of these choices are correct
C	Automatic amplitude and frequency numerical readout
D	Manipulation of time base after trace capture

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	100 watts
B	75 watts
C	125 watts
D	25 watts

17. - E4C17

Which of the following has the largest effect on an SDR receiver's linearity?

Select	Answer
A	RAM speed used for data storage
B	Analog-to-digital converter sample width in bits
C	Anti-aliasing input filter bandwidth
D	CPU register width in bits

18. - E4D05

What transmitter frequencies would cause an intermodulation-product signal in a receiver tuned to 146.70 MHz when a nearby station transmits on 146.52 MHz?

Select	Answer
A	146.10 MHz and 147.30 MHz
B	146.34 MHz and 146.61 MHz
C	146.88 MHz and 146.34 MHz
D	173.35 MHz and 139.40 MHz

19. - E4E01

Which of the following types of receiver noise can often be reduced by use of a receiver noise blanker?

Select	Answer
A	All of these choices are correct
B	Heterodyne interference
C	Broadband white noise
D	Ignition noise

20. - E5A01

What can cause the voltage across reactances in series to be larger than the voltage applied to them?

Select	Answer
A	Resistance
B	Resonance
C	Capacitance
D	Conductance

21. - E5B08

What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 100 ohms, R is 100 ohms, and XL is 75 ohms?

Select	Answer
A	14 degrees with the voltage lagging the current
B	14 degrees with the voltage leading the current
C	76 degrees with the voltage lagging the current
D	76 degrees with the voltage leading the current

22. - E5C17

Which point on Figure E5-2 best represents the impedance of a series circuit consisting of a 300 ohm resistor, a 0.64-microhenry inductor and an 85-picofarad capacitor at 24.900 MHz?

Select	Answer
A	Point 1
B	Point 3
C	Point 8
D	Point 5

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	1.0
B	0.5
C	0.707
D	0.866

24. - E6A01

In what application is gallium arsenide used as a semiconductor material in preference to germanium or silicon?

Select	Answer
A	In microwave circuits
B	In high-power audio circuits
C	In very low frequency RF circuits
D	In high-current rectifier circuits

25. - E6B05

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

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

26. - E6C08

In Figure E6-5, what is the schematic symbol for a NAND gate?

Select	Answer
A	3
B	2
C	1
D	4

27. - E6D06

What core material property determines the inductance of a toroidal inductor?

Select	Answer
A	Resistance
B	Permeability
C	Reactivity
D	Thermal impedance

28. - E6E12

Why are high-power RF amplifier ICs and transistors sometimes mounted in ceramic packages?

Select	Answer
A	High-voltage insulating ability
B	To provide a low-pass frequency response
C	Enhanced sensitivity to light
D	Better dissipation of heat

29. - E6F14

Which of the following is true of LCD displays?

Select	Answer
A	All of these choices are correct
B	They may be hard view through polarized lenses
C	They only display alphanumeric symbols
D	They are hard to view in high ambient light conditions

30. - E7A05

Which of the following is a circuit that continuously alternates between two states without an external clock?

Select	Answer
A	Astable multivibrator
B	J-K flip-flop
C	T flip-flop
D	Monostable multivibrator

31. - E7B03

Which of the following components form the output of a class D amplifier circuit?

Select	Answer
A	A matched load resistor to prevent damage by switching transients
B	A low-pass filter to remove switching signal components
C	A temperature compensating load resistor to improve linearity
D	A high-pass filter to compensate for low gain at low frequencies

32. - E7C05

Which filter type is described as having ripple in the passband and a sharp cutoff?

Select	Answer
A	A Chebyshev filter
B	A Butterworth filter
C	A passive op-amp filter
D	An active LC filter

33. - E7D08

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

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

34. - E7E04

What is one way a single-sideband phone signal can be generated?

Select	Answer
A	By driving a product detector with a DSB signal
B	By using a loop modulator followed by a mixer
C	By using a reactance modulator followed by a mixer
D	By using a balanced modulator followed by a filter

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	4 bits
B	6 bits
C	8 bits
D	10 bits

36. - E7G01

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

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

37. - E7H04

How is positive feedback supplied in a Colpitts oscillator?

Select	Answer
A	Through a capacitive divider
B	Through link coupling
C	Through a tapped coil
D	Through a neutralizing capacitor

38. - E8A03

What type of wave does a Fourier analysis show to be made up of sine waves of a given fundamental frequency plus all of its harmonics?

Select	Answer
A	A square wave
B	A sine wave
C	A sawtooth wave
D	A cosine wave

39. - E8B05

What is the deviation ratio of an FM-phone signal having a maximum frequency swing of plus-or-minus 5 kHz when the maximum modulation frequency is 3 kHz?

Select	Answer
A	0.6
B	0.167
C	1.67
D	60

40. - E8C04

What technique is used to minimize the bandwidth requirements of a PSK31 signal?

Select	Answer
A	Reed-Solomon character encoding
B	Use of sinusoidal data pulses
C	Zero-sum character encoding
D	Use of trapezoidal data pulses

41. - E8D10

What are some of the differences between the Baudot digital code and ASCII?

Select	Answer
A	Baudot uses 7 data bits per character, ASCII uses 8; Baudot has no letters/figures shift code, ASCII uses 2 letters/figures shift codes
B	Baudot uses 5 data bits per character, ASCII uses 7 or 8; Baudot uses 2 characters as letters/figures shift codes, ASCII has no letters/figures shift code
C	Baudot uses 4 data bits per character, ASCII uses 7 or 8; Baudot uses 1 character as a letters/figures shift code, ASCII has no letters/figures code
D	Baudot uses 6 data bits per character, ASCII uses 7 or 8; Baudot has no letters/figures shift code, ASCII uses 2 letters/figures shift codes

42. - E9A05

What is included in the total resistance of an antenna system?

Select	Answer
A	Radiation resistance plus ohmic resistance
B	Transmission-line resistance plus radiation resistance
C	Radiation resistance plus transmission resistance
D	Radiation resistance plus space impedance

43. - E9B05

What type of antenna pattern over real ground is shown in Figure E9-2?

Select	Answer
A	Radiation resistance
B	Elevation
C	Polarization
D	Azimuth

44. - E9C08

What is a folded dipole antenna?

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

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

46. - E9E07

What term best describes the interactions at the load end of a mismatched transmission line?

Select	Answer
A	Dielectric constant
B	Characteristic impedance
C	Velocity factor
D	Reflection coefficient

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

48. - E9G07

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

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

49. - E9H06

What is the triangulation method of direction finding?

Select	Answer
A	A fixed receiving station uses three different antennas to plot the location of the signal source
B	A fixed receiving station plots three headings to the signal source
C	Antenna headings from several different receiving locations are used to locate the signal source
D	The geometric angles of sky waves from the source are used to determine its position

50. - E0A03

Which of the following would be a practical way to estimate whether the RF fields produced by an amateur radio station are within permissible MPE limits?

Select	Answer
A	Use an antenna modeling program to calculate field strength at accessible locations
B	Use a calibrated antenna analyzer
C	All of the choices are correct
D	Use a hand calculator plus Smith-chart equations to calculate the fields

Figure E5-2

Figure E6-5

Figure E7-3

Figure E9-2

Figure E9-3