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

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1. - E1A04

With your transceiver displaying the carrier frequency of phone signals, you hear a DX station calling CQ on 3.601 MHz LSB. Is it legal to return the call using lower sideband on the same frequency?

Select	Answer
A	No, U.S. stations are not permitted to use phone emissions below 3.610 MHz
B	Yes, because the DX station initiated the contact
C	No, the sideband will extend beyond the edge of the phone band segment
D	Yes, because the displayed frequency is within the 75 meter phone band segment

2. - E1B05

What is the National Radio Quiet Zone?

Select	Answer
A	An area in Florida surrounding Cape Canaveral
B	An area in New Mexico surrounding the White Sands Test Area
C	An area in Puerto Rico surrounding the Arecibo Radio Telescope
D	An area surrounding the National Radio Astronomy Observatory

3. - E1C01

What is a remotely controlled station?

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

4. - E1D01

What is the definition of the term telemetry?

Select	Answer
A	Two-way radiotelephone transmissions in excess of 1000 feet
B	One-way transmission of measurements at a distance from the measuring instrument
C	One-way transmission that initiates, modifies, or terminates the functions of a device at a distance
D	Two-way single channel transmissions of data

5. - E1E01

What is the minimum number of qualified VEs required to administer an Element 4 amateur operator license examination?

Select	Answer
A	2
B	5
C	3
D	4

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	420 MHz - 430 MHz
B	53 MHz - 54 MHz
C	440 MHz - 450 MHz
D	222 MHz - 223 MHz

7. - E2A01

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

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

8. - E2B04

What is blanking in a video signal?

Select	Answer
A	Transmitting a black and white test pattern
B	Turning off the scanning beam at the conclusion of a transmission
C	Turning off the scanning beam while it is traveling from right to left or from bottom to top
D	Synchronization of the horizontal and vertical sync pulses

9. - E2C08

Which of the following contacts may be confirmed through the U.S. QSL bureau system?

Select	Answer
A	Contacts using tactical call signs
B	Special event contacts between stations in the U.S.
C	Repeater contacts between U.S. club members
D	Contacts between a U.S. station and a non-U.S. station

10. - E2D09

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

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

11. - E2E08

Which of the following HF digital modes can be used to transfer binary files?

Select	Answer
A	Hellschreiber
B	RTTY
C	PACTOR
D	AMTOR

12. - E3A10

Which type of atmospheric structure can create a path for microwave propagation?

Select	Answer
A	Temperature inversion
B	Dust devil
C	The jet stream
D	Wind shear

13. - E3B14

What happens to linearly polarized radio waves that split into ordinary and extraordinary waves in the ionosphere?

Select	Answer
A	They are bent toward the magnetic poles
B	Their polarization is randomly modified
C	They become phase-locked
D	They become elliptically polarized

14. - E3C04

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

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

15. - E4A07

Which of the following is an advantage of using an antenna analyzer compared to an SWR bridge to measure antenna SWR?

Select	Answer
A	Antenna analyzers display a time-varying representation of the modulation envelope
B	All of these choices are correct
C	Antenna analyzers automatically tune your antenna for resonance
D	Antenna analyzers do not need an external RF source

16. - E4B02

What is an advantage of using a bridge circuit to measure impedance?

Select	Answer
A	It provides an excellent match under all conditions
B	It is relatively immune to drift in the signal generator source
C	It can display results directly in Smith chart format
D	It is very precise in obtaining a signal null

17. - E4C15

What is usually the primary source of noise that is heard from an HF receiver with an antenna connected?

Select	Answer
A	Atmospheric noise
B	Receiver front-end noise
C	Detector noise
D	Induction motor noise

18. - E4D01

What is meant by the blocking dynamic range of a receiver?

Select	Answer
A	The difference in dB between the noise floor and the level of an incoming signal which will cause 1 dB of gain compression
B	The minimum difference in dB between two signals which produce third order intermodulation products greater than the noise floor
C	The difference in dB between the noise floor and the third order intercept point
D	The minimum difference in dB between the levels of two FM signals which will cause one signal to block the other

19. - E4E03

Which of the following signals might a receiver noise blanker be able to remove from desired signals?

Select	Answer
A	Signals which appear at one IF but not another
B	Signals which have a sharply peaked frequency distribution
C	Signals which appear across a wide bandwidth
D	Signals which are constant at all IF levels

20. - E5A05

What is the magnitude of the current at the input of a series RLC circuit as the frequency goes through resonance?

Select	Answer
A	Minimum
B	L/R
C	R/L
D	Maximum

21. - E5B03

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

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

22. - E5C03

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

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

23. - E5D12

How many watts are consumed in a circuit having a power factor of 0.2 if the input is 100-VAC at 4 amperes?

Select	Answer
A	2000 watts
B	80 watts
C	50 watts
D	400 watts

24. - E6A16

What are the majority charge carriers in N-type semiconductor material?

Select	Answer
A	Holes
B	Free electrons
C	Free protons
D	Free neutrons

25. - E6B08

Which of the following describes a type of semiconductor diode?

Select	Answer
A	Thermionic emission diode
B	CMOS-field effect
C	Electrolytic rectifier
D	Metal-semiconductor junction

26. - E6C05

What is an advantage of CMOS logic devices over TTL devices?

Select	Answer
A	Lower distortion
B	Lower power consumption
C	Differential output capability
D	Immune to damage from static discharge

27. - E6D08

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

Select	Answer
A	Powdered-iron cores generally maintain their characteristics at higher currents
B	Powdered-iron cores generally have greater initial permeability
C	Powdered-iron cores generally require fewer turns to produce a given inductance
D	Powdered-iron cores use smaller diameter wire for the same inductance

28. - E6E12

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

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

29. - E6F04

What is the photovoltaic effect?

Select	Answer
A	The conversion of light to electrical energy
B	The conversion of voltage to current when exposed to light
C	The conversion of electrical energy to mechanical energy
D	The tendency of a battery to discharge when used outside

30. - E7A08

What logical operation does an OR gate perform?

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

31. - E7B17

Why are odd-order rather than even-order intermodulation distortion products of concern in linear power amplifiers?

Select	Answer
A	Because they are relatively far in frequency from the desired signal
B	Because they invert the sidebands causing distortion
C	Because they maintain the sidebands, thus causing multiple duplicate signals
D	Because they are relatively close in frequency to the desired signal

32. - E7C06

What are the distinguishing features of an elliptical filter?

Select	Answer
A	Gradual passband rolloff with minimal stop band ripple
B	Gradual passband rolloff with extreme stop band ripple
C	Extremely sharp cutoff with one or more notches in the stop band
D	Extremely flat response over its pass band with gradually rounded stop band corners

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 allow the filter capacitors to charge gradually
C	To compensate for variations of the incoming line voltage
D	To provide a dual-voltage output for reduced power applications

34. - E7E06

Why is de-emphasis commonly used in FM communications receivers?

Select	Answer
A	To remove third-order distortion products
B	To reduce impulse noise reception
C	For compatibility with transmitters using phase modulation
D	For higher efficiency

35. - E7F13

What is the function of taps in a digital signal processing filter?

Select	Answer
A	To reduce excess signal pressure levels
B	Provide incremental signal delays for filter algorithms
C	Provide access for debugging software
D	Select the point at which baseband signals are generated

36. - E7G05

How can unwanted ringing and audio instability be prevented in a multi-section op-amp RC audio filter circuit?

Select	Answer
A	Restrict Q but increase gain
B	Restrict gain but increase Q
C	Restrict both gain and Q
D	Increase both gain and Q

37. - E7H08

Which of the following components can be used to reduce thermal drift in crystal oscillators?

Select	Answer
A	NP0 capacitors
B	Toroidal inductors
C	Wirewound resistors
D	Non-inductive resistors

38. - E8A11

What type of information can be conveyed using digital waveforms?

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

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. - E8C05

What is the necessary bandwidth of a 13-WPM international Morse code transmission?

Select	Answer
A	Approximately 52 Hz
B	Approximately 26 Hz
C	Approximately 13 Hz
D	Approximately 104 Hz

41. - E8D07

What is a common cause of overmodulation of AFSK signals?

Select	Answer
A	Bit errors in the modem
B	Ground loops
C	Excessive numbers of retries
D	Excessive transmit audio levels

42. - E9A05

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

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

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	The gain may change depending on frequency
D	Feed point impedance may become negative

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 horizontal beam width decreases in the downhill direction
B	The horizontal beam width increases in the uphill direction
C	The main lobe takeoff angle decreases in the downhill direction
D	The main lobe takeoff angle increases in the downhill 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 decreases and the capacitive reactance decreases
B	The radiation resistance increases and the capacitive reactance decreases
C	The radiation resistance decreases and the capacitive reactance increases
D	The radiation resistance increases and the capacitive reactance increases

46. - E9E01

What system matches a higher impedance transmission line to a lower impedance antenna by connecting the line to the driven element in two places spaced a fraction of a wavelength each side of element center?

Select	Answer
A	The stub matching system
B	The delta matching system
C	The omega matching system
D	The gamma matching system

47. - E9F06

What is the approximate physical length of an air-insulated, parallel conductor transmission line that is electrically one-half wavelength long at 14.10 MHz?

Select	Answer
A	10 meters
B	71 meters
C	20 meters
D	15 meters

48. - E9G02

What type of coordinate system is used in a Smith chart?

Select	Answer
A	Resistance lines and reactance chords
B	Voltage lines and current chords
C	Resistance circles and reactance arcs
D	Voltage circles and current arcs

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

50. - E0A08

What does SAR measure?

Select	Answer
A	Signal Amplification Rating
B	The rate at which RF energy is absorbed by the body
C	Synthetic Aperture Ratio of the human body
D	The rate of RF energy reflected from stationary terrain