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

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1. - E1A07

Which amateur band requires transmission on specific channels rather than on a range of frequencies?

Select	Answer
A	12 meter band
B	60 meter band
C	17 meter band
D	30 meter band

2. - E1B10

What frequencies are authorized to an amateur station operating under RACES rules?

Select	Answer
A	All amateur service frequencies authorized to the control operator
B	Military Auxiliary Radio System (MARS) channels
C	Specific local government channels
D	Specific segments in the amateur service MF, HF, VHF and UHF bands

3. - E1C06

Which of the following statements concerning remotely controlled amateur stations is true?

Select	Answer
A	Only Extra Class operators may be the control operator of a remote station
B	A control operator need not be present at the control point
C	A control operator must be present at the control point
D	Repeater and auxiliary stations may not be remotely controlled

4. - E1D10

Which amateur stations are eligible to be telecommand stations?

Select	Answer
A	Any amateur station so designated by the ITU
B	All of these choices are correct
C	Any amateur station designated by NASA
D	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

5. - E1E12

What must the VE team do with the application form if the examinee does not pass the exam?

Select	Answer
A	Send the application form to the FCC and inform the FCC of the grade
B	Destroy the application form
C	Return the application document to the examinee
D	Maintain the application form with the VEC's records

6. - E1F03

Under what circumstances may a dealer sell an external RF power amplifier capable of operation below 144 MHz if it has not been granted FCC certification?

Select	Answer
A	It was imported from a manufacturer in a country that does not require certification of RF power amplifiers
B	The equipment dealer assembled it from a kit
C	It was purchased in used condition from an amateur operator and is sold to another amateur operator for use at that operator's station
D	It was imported from a manufacturer in another country and was certificated by that country's government

7. - E2A03

What is the orbital period of an Earth satellite?

Select	Answer
A	The time it takes for a satellite to travel from perigee to apogee
B	The point of maximum height of a satellite's orbit
C	The point of minimum height of a satellite's orbit
D	The time it takes for a satellite to complete one revolution around the Earth

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

9. - E2C03

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

Select	Answer
A	33 cm
B	2 m
C	30 m
D	6 m

10. - E2D10

How can an APRS station be used to help support a public service communications activity?

Select	Answer
A	An APRS station with an emergency medical technician can automatically transmit medical data to the nearest hospital
B	APRS stations with General Personnel Scanners can automatically relay the participant numbers and time as they pass the check points
C	An APRS station with a GPS unit can automatically transmit information to show a mobile station's position during the event
D	All of these choices are correct

11. - E2E07

What is the typical bandwidth of a properly modulated MFSK16 signal?

Select	Answer
A	550 Hz
B	2.16 kHz
C	316 Hz
D	31 Hz

12. - E3A04

What do Hepburn maps predict?

Select	Answer
A	Sporadic E propagation
B	Likelihood of rain-scatter along cold or warm fronts
C	Locations of auroral reflecting zones
D	Probability of tropospheric propagation

13. - E3B10

What is the cause of gray-line propagation?

Select	Answer
A	At twilight and sunrise, D-layer absorption is low while E-layer and F-layer propagation remains high
B	At midday, the Sun super heats the ionosphere causing increased refraction of radio waves
C	At mid-afternoon, the Sun heats the ionosphere decreasing radio wave refraction and the MUF
D	In darkness, solar absorption drops greatly while atmospheric ionization remains steady

14. - E3C11

What does VOACAP software model?

Select	Answer
A	VHF radio propagation
B	HF propagation
C	AC voltage and impedance
D	AC current and impedance

15. - E4A14

What is the purpose of the prescaler function on a frequency counter?

Select	Answer
A	It divides a higher frequency signal so a low-frequency counter can display the input frequency
B	It multiplies a higher frequency signal so a low-frequency counter can display the operating frequency
C	It amplifies low level signals for more accurate counting
D	It prevents oscillation in a low-frequency counter circuit

16. - E4B09

What is indicated if the current reading on an RF ammeter placed in series with the antenna feed line of a transmitter increases as the transmitter is tuned to resonance?

Select	Answer
A	There is more power going into the antenna
B	There is possibly a short to ground in the feed line
C	The transmitter is not properly neutralized
D	There is an impedance mismatch between the antenna and feed line

17. - E4C17

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

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

18. - E4D13

Which of the following can cause receiver desensitization?

Select	Answer
A	Audio bias adjusted too high
B	Strong adjacent channel signals
C	Audio gain adjusted too low
D	Squelch gain misadjusted

19. - E4E07

How can you determine if line noise interference is being generated within your home?

Select	Answer
A	By turning off the AC power line main circuit breaker and listening on a battery operated radio
B	By checking the power line voltage with a time domain reflectometer
C	By observing the AC power line voltage with a spectrum analyzer
D	By observing the AC power line waveform with an oscilloscope

20. - E5A17

What is the result of increasing the Q of an impedance-matching circuit?

Select	Answer
A	Matching bandwidth is increased
B	It has no effect on impedance matching
C	Matching bandwidth is decreased
D	Matching range is increased

21. - E5B12

What is admittance?

Select	Answer
A	The inverse of impedance
B	The term for the gain of a field effect transistor
C	The unit used for Q factor
D	The turns ratio of a transformer

22. - E5C01

Which of the following represents a capacitive reactance in rectangular notation?

Select	Answer
A	+jX
B	Omega
C	-jX
D	X

23. - E5D18

How many watts are consumed in a circuit having a power factor of 0.71 if the apparent power is 500VA?

Select	Answer
A	704 W
B	1.42 mW
C	355 W
D	252 W

24. - E6A14

How does DC input impedance at the gate of a field-effect transistor compare with the DC input impedance of a bipolar transistor?

Select	Answer
A	An FET has low input impedance; a bipolar transistor has high input impedance
B	An FET has high input impedance; a bipolar transistor has low input impedance
C	They are both high impedance
D	They are both low impedance

25. - E6B06

Which of the following is a common use of a hot-carrier diode?

Select	Answer
A	As a constant voltage reference in a power supply
B	As a variable capacitance in an automatic frequency control circuit
C	As balanced mixers in FM generation
D	As a VHF/UHF mixer or detector

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	Many similar gates are less expensive than a mixture of gate types
D	All of these choices are correct

27. - 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 confine most of the magnetic field within the core material
C	Toroidal cores have lower Q characteristics
D	Toroidal cores make it easier to couple the magnetic energy into other components

28. - E6E08

How is voltage from a power supply normally furnished to the most common type of monolithic microwave integrated circuit (MMIC)?

Select	Answer
A	MMICs require no operating bias
B	Directly to the bias voltage (VCC IN) lead
C	Through a resistor and/or RF choke connected to the amplifier output lead
D	Through a capacitor and RF choke connected to the amplifier input lead

29. - E6F13

What is a liquid crystal display (LCD)?

Select	Answer
A	A display utilizing a crystalline liquid and polarizing filters which becomes opaque when voltage is applied
B	A modern replacement for a quartz crystal oscillator which displays its fundamental frequency
C	A display that uses a glowing liquid to remain brightly lit in dim light
D	A frequency-determining unit for a transmitter or receiver

30. - E7A04

How many flip-flops are required to divide a signal frequency by 4?

Select	Answer
A	1
B	8
C	2
D	4

31. - E7B14

Why are switching amplifiers more efficient than linear amplifiers?

Select	Answer
A	Switching amplifiers use push-pull circuits
B	Switching amplifiers operate at higher voltages
C	Linear amplifiers have high gain resulting in higher harmonic content
D	The power transistor is at saturation or cut off most of the time, resulting in low power dissipation

32. - E7C07

What kind of filter would you use to attenuate an interfering carrier signal while receiving an SSB transmission?

Select	Answer
A	A Pi-network filter
B	A band-pass filter
C	A notch filter
D	An all-pass filter

33. - E7D01

What is one characteristic of a linear electronic voltage regulator?

Select	Answer
A	It eliminates the need for a pass transistor
B	The conduction of a control element is varied to maintain a constant output voltage
C	The control element duty cycle is proportional to the line or load conditions
D	It has a ramp voltage as its output

34. - E7E06

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

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

35. - E7F13

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

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

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 both gain and Q
B	Restrict Q but increase gain
C	Restrict gain but increase Q
D	Increase both gain and Q

37. - E7H05

How is positive feedback supplied in a Pierce oscillator?

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

38. - E8A02

What type of wave has a rise time significantly faster than its fall time (or vice versa)?

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

39. - E8B10

What describes frequency division multiplexing?

Select	Answer
A	The transmitted signal is divided into packets of information
B	Two or more information streams are merged into a digital combiner, which then pulse position modulates the transmitter
C	Two or more information streams are merged into a baseband, which then modulates the transmitter
D	The transmitted signal jumps from band to band at a predetermined rate

40. - E8C10

What is an advantage of Gray code in digital communications where symbols are transmitted as multiple bits

Select	Answer
A	It facilitates error detection
B	It increases security
C	It has more resolution than simple binary
D	It has more possible states than simple binary

41. - E8D02

What spread spectrum communications technique uses a high speed binary bit stream to shift the phase of an RF carrier?

Select	Answer
A	Direct sequence
B	Frequency hopping
C	Phase compandored spread spectrum
D	Binary phase-shift keying

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 ratio of the amount of power radiated by an antenna compared to the transmitter output power
C	The ratio of the signal in the forward direction to that in the opposite direction
D	The final amplifier gain minus the transmission line losses

43. - E9B16

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

Select	Answer
A	3
B	4
C	7
D	1

44. - E9C08

What is a folded dipole antenna?

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

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 losses
C	To swamp out harmonics
D	To minimize the Q

46. - E9E04

What is the purpose of the series capacitor in a gamma-type antenna matching network?

Select	Answer
A	To provide a rejection notch that prevents the radiation of harmonics
B	To provide DC isolation between the feed line and the antenna
C	To transform the antenna impedance to a higher value
D	To cancel the inductive reactance of the matching network

47. - E9F09

What is the approximate physical length of a solid polyethylene dielectric coaxial transmission line that is electrically one-quarter wavelength long at 7.2 MHz?

Select	Answer
A	10 meters
B	6.9 meters
C	24 meters
D	50 meters

48. - E9G08

What is the process of normalization with regard to a Smith chart?

Select	Answer
A	Reassigning impedance values with regard to the prime center
B	Reassigning resistance values with regard to the reactance axis
C	Reassigning prime center with regard to the reactance axis
D	Reassigning reactance values with regard to the resistance axis

49. - E9H05

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

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

50. - E0A04

When evaluating a site with multiple transmitters operating at the same time, the operators and licensees of which transmitters are responsible for mitigating over-exposure situations?

Select	Answer
A	Only commercial transmitters
B	Each transmitter that produces 5 percent or more of its MPE limit at accessible locations
C	Only the most powerful transmitter
D	Each transmitter operating with a duty-cycle greater than 50 percent

Figure E9-2