US Amateur Radio - Amateur Extra (Element 4, 2020-2024) Practice Test

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1. - E0A08

What does SAR measure?

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

2. - E1A13

Who must be in physical control of the station apparatus of an amateur station aboard any vessel or craft that is documented or registered in the United States?

Select	Answer
A	Any person named in an amateur station license grant or a person holding an unrestricted Radiotelephone Operator Permit
B	Any person holding an FCC issued amateur license or who is authorized for alien reciprocal operation
C	Only a person with an FCC Marine Radio license grant
D	Only a person named in an amateur station license grant

3. - E1B08

What limitations may the FCC place on an amateur station if its signal causes interference to domestic broadcast reception, assuming that the receivers involved are of good engineering design?

Select	Answer
A	The amateur station must cease operation on all frequencies above 30 MHz
B	The amateur station must cease operation on all frequencies below 30 MHz
C	The amateur station must avoid transmitting during certain hours on frequencies that cause the interference
D	The amateur station must cease operation

4. - E1C05

When may an automatically controlled station originate third party communications?

Select	Answer
A	When agreed upon by the sending or receiving station
B	When approved by the National Telecommunication and Information Administration
C	Never
D	Only when transmitting RTTY or data emissions

5. - E1D09

Which UHF amateur bands have frequencies authorized for space stations?

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

6. - E1E04

Which of the following best describes the Volunteer Examiner accreditation process?

Select	Answer
A	The prospective VE obtains accreditation from the FCC
B	Each General, Advanced and Amateur Extra Class operator is automatically accredited as a VE when the license is granted
C	The amateur operator applying must pass a VE examination administered by the FCC Enforcement Bureau
D	The procedure by which a VEC confirms that the VE applicant meets FCC requirements to serve as an examiner

7. - E1F07

When may an amateur station send a message to a business?

Select	Answer
A	When the total money involved does not exceed $25
B	When neither the amateur nor his or her employer has a pecuniary interest in the communications
C	When the control operator is employed by the FCC or another government agency
D	When transmitting international third-party communications

8. - E2A01

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

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

9. - E2B04

How is color information sent in analog SSTV?

Select	Answer
A	Color is sent in a color burst at the end of each line
B	Color lines are sent sequentially
C	Color is amplitude modulated on the frequency modulated intensity signal
D	Color information is sent on a 2.8 kHz subcarrier

10. - E2C03

From which of the following bands is amateur radio contesting generally excluded?

Select	Answer
A	33 centimeters
B	6 meters
C	30 meters
D	2 meters

11. - E2D01

Which of the following digital modes is designed for meteor scatter communications?

Select	Answer
A	Hellschreiber
B	WSPR
C	APRS
D	MSK144

12. - E2E02

What do the letters FEC mean as they relate to digital operation?

Select	Answer
A	Fatal Error Correction
B	Final Error Correction
C	Forward Error Correction
D	First Error Correction

13. - E3A12

What is the cause of auroral activity?

Select	Answer
A	Meteor showers concentrated in the extreme northern and southern latitudes
B	The interaction in the F2 layer between the solar wind and the Van Allen belt
C	The interaction in the E layer of charged particles from the Sun with the Earth's magnetic field
D	An extreme low-pressure area in the polar regions

14. - E3B12

What is the primary characteristic of chordal hop propagation?

Select	Answer
A	Propagation across the geomagnetic equator
B	Successive ionospheric refractions without an intermediate reflection from the ground
C	Signals reflected back toward the transmitting station
D	Propagation away from the great circle bearing between stations

15. - E3C06

By how much does the VHF/UHF radio horizon distance exceed the geometric horizon?

Select	Answer
A	By approximately 50 percent of the distance
B	By approximately four times the distance
C	By approximately 15 percent of the distance
D	By approximately twice the distance

16. - E4A11

How should an antenna analyzer be connected when measuring antenna resonance and feed point impedance?

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

17. - 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	125 watts
B	75 watts
C	100 watts
D	25 watts

18. - E4C07

What does the MDS of a receiver represent?

Select	Answer
A	The maximum detectable spectrum
B	The meter display sensitivity
C	The multiplex distortion stability
D	The minimum discernible signal

19. - E4D07

Which of the following reduces the likelihood of receiver desensitization?

Select	Answer
A	Raise the receiver IF frequency
B	Switch from fast AGC to slow AGC
C	Decrease the RF bandwidth of the receiver
D	Increase the receiver front end gain

20. - E4E01

What problem can occur when using an automatic notch filter (ANF) to remove interfering carriers while receiving CW signals?

Select	Answer
A	Received CW signals will appear to be modulated at the DSP clock frequency
B	Ringing in the DSP filter will completely remove the spaces between the CW characters
C	Removal of the CW signal as well as the interfering carrier
D	Any nearby signal passing through the DSP system will overwhelm the desired signal

21. - E5A08

What is the phase relationship between the current through and the voltage across a series resonant circuit at resonance?

Select	Answer
A	The current leads the voltage by 90 degrees
B	The voltage leads the current by 90 degrees
C	The voltage and current are 180 degrees out of phase
D	The voltage and current are in phase

22. - 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

23. - E5C04

What coordinate system is often used to display the resistive, inductive, and/or capacitive reactance components of impedance?

Select	Answer
A	Maidenhead grid
B	Rectangular coordinates
C	Faraday grid
D	Elliptical coordinates

24. - 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 these choices are correct
C	To avoid unwanted inductive reactance
D	To maintain component lifetime

25. - E6A03

Why does a PN-junction diode not conduct current when reverse biased?

Select	Answer
A	Excess holes in P-type material combine with the electrons in N-type material, converting the entire diode into an insulator
B	Only N-type semiconductor material can conduct current
C	Only P-type semiconductor material can conduct current
D	Holes in P-type material and electrons in the N-type material are separated by the applied voltage, widening the depletion region

26. - E6B05

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

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

27. - E6C04

Which of the following is an advantage of BiCMOS logic?

Select	Answer
A	It has the high input impedance of CMOS and the low output impedance of bipolar transistors
B	All these choices are correct
C	Its simplicity results in much less expensive devices than standard CMOS
D	It is immune to electrostatic damage

28. - E6D10

What is a primary advantage of using a toroidal core instead of a solenoidal core in an inductor?

Select	Answer
A	Toroidal cores exhibit greater hysteresis
B	Toroidal cores make it easier to couple the magnetic energy into other components
C	Toroidal cores have lower Q characteristics
D	Toroidal cores confine most of the magnetic field within the core material

29. - E6E09

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

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

30. - 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

31. - E7A01

Which circuit is bistable?

Select	Answer
A	An OR gate
B	An AND gate
C	A bipolar amplifier
D	A flip-flop

32. - E7B18

What is a characteristic of a grounded-grid amplifier?

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

33. - E7C10

Which of the following filters would be the best choice for use in a 2 meter band repeater duplexer?

Select	Answer
A	A cavity filter
B	A crystal filter
C	An L-C filter
D	A DSP filter

34. - E7D04

Which of the following types of linear voltage regulator usually make the most efficient use of the primary power source?

Select	Answer
A	A shunt regulator
B	A series regulator
C	A shunt current source
D	A series current source

35. - E7E05

What circuit is added to an FM transmitter to boost the higher audio frequencies?

Select	Answer
A	A heterodyne enhancer
B	A heterodyne suppressor
C	A pre-emphasis network
D	A de-emphasis network

36. - E7F12

Which of the following is an advantage of a Finite Impulse Response (FIR) filter vs an Infinite Impulse Response (IIR) digital filter?

Select	Answer
A	FIR filters can respond faster to impulses
B	FIR filters are easier to implement for a given set of passband rolloff requirements
C	All these choices are correct
D	FIR filters can delay all frequency components of the signal by the same amount

37. - E7G06

What is the gain-bandwidth of an operational amplifier?

Select	Answer
A	The gain of the amplifier at a filter's cutoff frequency
B	The maximum frequency for a filter circuit using that type of amplifier
C	The frequency at which the open-loop gain of the amplifier equals one
D	The frequency at which the amplifier's offset voltage is zero

38. - E7H05

How is positive feedback supplied in a Pierce oscillator?

Select	Answer
A	Through a neutralizing capacitor
B	Through a quartz crystal
C	Through link coupling
D	Through a tapped coil

39. - E8A02

Which of the following is a type of analog-to-digital conversion?

Select	Answer
A	Phase reversal
B	Harmonic regeneration
C	Successive approximation
D	Level shifting

40. - E8B03

What is the modulation index of an FM-phone signal having a maximum frequency deviation of 3000 Hz either side of the carrier frequency when the modulating frequency is 1000 Hz?

Select	Answer
A	0.3
B	3000
C	3
D	1000

41. - E8C06

What is the bandwidth of a 170-hertz shift, 300-baud ASCII transmission?

Select	Answer
A	1.0 kHz
B	0.1 Hz
C	0.3 kHz
D	0.5 kHz

42. - E8D11

What is one advantage of using ASCII code for data communications?

Select	Answer
A	It is possible to transmit both upper and lower case text
B	It includes built-in error correction features
C	It uses one character as a shift code to send numeric and special characters
D	It contains fewer information bits per character than any other code

43. - E9A03

What is the radiation resistance of an antenna?

Select	Answer
A	The resistance in the atmosphere that an antenna must overcome to be able to radiate a signal
B	The value of a resistance that would dissipate the same amount of power as that radiated from an antenna
C	The combined losses of the antenna elements and feed line
D	The specific impedance of the antenna

44. - E9B08

What is the far field of an antenna?

Select	Answer
A	The region where radiated field strengths are constant
B	The region where the shape of the antenna pattern is independent of distance
C	The region of the ionosphere where radiated power is not refracted
D	The region where radiated power dissipates over a specified time period

45. - E9C06

What is the effect of adding a terminating resistor to a rhombic antenna?

Select	Answer
A	It changes the radiation pattern from horizontal to vertical polarization
B	It reflects the standing waves on the antenna elements back to the transmitter
C	It changes the radiation pattern from bidirectional to unidirectional
D	It decreases the ground loss

46. - E9D08

What happens as the Q of an antenna increases?

Select	Answer
A	More common-mode current is present on the feed line
B	Gain is reduced
C	SWR bandwidth increases
D	SWR bandwidth decreases

47. - E9E11

What is the primary purpose of phasing lines when used with an antenna having multiple driven elements?

Select	Answer
A	It ensures that each driven element operates in concert with the others to create the desired antenna pattern
B	It prevents reflected power from traveling back down the feed line and causing harmonic radiation from the transmitter
C	It creates a low-angle radiation pattern
D	It allows single-band antennas to operate on other bands

48. - E9F02

Which of the following has the biggest effect on the velocity factor of a transmission line?

Select	Answer
A	The center conductor resistivity
B	Dielectric materials used in the line
C	The line length
D	The termination impedance

49. - E9G01

Which of the following can be calculated using a Smith chart?

Select	Answer
A	Antenna radiation pattern
B	Radio propagation
C	Radiation resistance
D	Impedance along transmission lines

50. - E9H03

What is Receiving Directivity Factor (RDF)?

Select	Answer
A	Relative directivity compared to isotropic
B	Forward gain compared to the gain in the reverse direction
C	Relative directivity compared to a dipole
D	Forward gain compared to average gain over the entire hemisphere