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

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1. - E1A10

If an amateur station is installed aboard a ship or aircraft, what condition must be met before the station is operated?

Select	Answer
A	The amateur operator must have an FCC Marine or Aircraft endorsement on his or her amateur license
B	The amateur station operator must agree not to transmit when the main radio of the ship or aircraft is in use
C	Its operation must be approved by the master of the ship or the pilot in command of the aircraft
D	The amateur station must have a power supply that is completely independent of the main ship or aircraft power supply

2. - E1B07

What is the highest modulation index permitted at the highest modulation frequency for angle modulation below 29.0 MHz?

Select	Answer
A	3.0
B	1.0
C	2.0
D	0.5

3. - E1C10

What types of amateur stations may automatically retransmit the radio signals of other amateur stations?

Select	Answer
A	Only auxiliary, beacon or space stations
B	Only beacon, repeater or space stations
C	Only auxiliary, repeater or space stations
D	Only earth stations, repeater stations or model craft

4. - E1D04

What is an Earth station in the amateur satellite service?

Select	Answer
A	Any amateur station on the surface of the Earth
B	An amateur station within 50 km of the Earth's surface intended for communications with amateur stations by means of objects in space
C	An amateur station that is not able to communicate using amateur satellites
D	An amateur station that transmits telemetry consisting of measurement of upper atmosphere

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	Maintain the application form with the VEC's records
C	Destroy the application form
D	Return the application document to the examinee

6. - E1F08

Which of the following types of amateur station communications are prohibited?

Select	Answer
A	Communications that have a political content, except as allowed by the Fairness Doctrine
B	Communications in a language other than English
C	Communications transmitted for hire or material compensation, except as otherwise provided in the rules
D	Communications that have a religious content

7. - E2A09

What do the terms L band and S band specify with regard to satellite communications?

Select	Answer
A	The 23 centimeter and 13 centimeter bands
B	Which sideband to use
C	The 2 meter and 70 centimeter bands
D	FM and Digital Store-and-Forward systems

8. - E2B02

How many horizontal lines make up a fast-scan (NTSC) television frame?

Select	Answer
A	525
B	30
C	60
D	1080

9. - E2C04

What type of transmission is most often used for a ham radio mesh network?

Select	Answer
A	Spread spectrum in the 2.4 GHz band
B	Store and forward on the 440 MHz band
C	Multiple Frequency Shift Keying in the 10 GHz band
D	Frequency division multiplex in the 24 GHz band

10. - E2D03

Which of the following digital modes is especially useful for EME communications?

Select	Answer
A	JT65
B	PACTOR III
C	Olivia
D	FSK441

11. - E2E11

What is the difference between direct FSK and audio FSK?

Select	Answer
A	Audio FSK can be performed anywhere in the transmit chain
B	Direct FSK applies the data signal to the transmitter VFO
C	Audio FSK has a superior frequency response
D	Direct FSK uses a DC-coupled data connection

12. - E3A08

When a meteor strikes the Earth's atmosphere, a cylindrical region of free electrons is formed at what layer of the ionosphere?

Select	Answer
A	The E layer
B	The F2 layer
C	The F1 layer
D	The D layer

13. - E3B05

Which amateur bands typically support long-path propagation?

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

14. - E3C04

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

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

15. - E4A14

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

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

16. - E4B14

What happens if a dip meter is too tightly coupled to a tuned circuit being checked?

Select	Answer
A	A less accurate reading results
B	Harmonics are generated
C	Intermodulation distortion occurs
D	Cross modulation occurs

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	Squelch gain misadjusted
C	Audio gain adjusted too low
D	Strong adjacent channel signals

19. - E4E05

How can noise from an electric motor be suppressed?

Select	Answer
A	By installing a brute-force AC-line filter in series with the motor leads
B	By using a ground-fault current interrupter in the circuit used to power the motor
C	By installing a high pass filter in series with the motor's power leads
D	By installing a bypass capacitor in series with the motor leads

20. - E5A08

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

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

21. - E5B09

What is the relationship between the current through a capacitor and the voltage across a capacitor?

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

22. - E5C15

Which point in Figure E5-2 best represents the impedance of a series circuit consisting of a 300 ohm resistor and an 18 microhenry inductor at 3.505 MHz?

Select	Answer
A	Point 7
B	Point 3
C	Point 1
D	Point 8

23. - E5D10

How can the true power be determined in an AC circuit where the voltage and current are out of phase?

Select	Answer
A	By multiplying the apparent power times the power factor
B	By multiplying the reactive power times the power factor
C	By dividing the apparent power by the power factor
D	By dividing the reactive power by the power factor

24. - E6A03

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

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

25. - E6B07

What is the failure mechanism when a junction diode fails due to excessive current?

Select	Answer
A	Excessive inverse voltage
B	Insufficient forward voltage
C	Charge carrier depletion
D	Excessive junction temperature

26. - E6C09

What is a Programmable Logic Device (PLD)?

Select	Answer
A	A programmable collection of logic gates and circuits in a single integrated circuit
B	An algorithm for simulating logic functions during circuit design
C	Programmable equipment used for testing digital logic integrated circuits
D	A device to control industrial equipment

27. - E6D17

Why should core saturation of a conventional impedance matching transformer be avoided?

Select	Answer
A	Harmonics and distortion could result
B	RF susceptance would increase
C	Magnetic flux would increase with frequency
D	Temporary changes of the core permeability could result

28. - E6E11

What is a characteristic of DIP packaging used for integrated circuits?

Select	Answer
A	Two chips in each package (Dual In Package)
B	A total of two rows of connecting pins placed on opposite sides of the package (Dual In-line Package)
C	Low leakage doubly insulated package
D	Package mounts in a direct inverted position

29. - E6F04

What is the photovoltaic effect?

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

30. - E7A08

What logical operation does an OR gate perform?

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

31. - E7B02

What is a Class D amplifier?

Select	Answer
A	A type of amplifier that uses switching technology to achieve high efficiency
B	A frequency doubling amplifier
C	An amplifier that uses drift-mode FETs for high efficiency
D	A low power amplifier that uses a differential amplifier for improved linearity

32. - E7C11

Which of the following is the common name for a filter network which is equivalent to two L-networks connected back-to-back with the two inductors in series and the capacitors in shunt at the input and output?

Select	Answer
A	Pi-L
B	Cascode
C	Omega
D	Pi

33. - E7D09

What is the main reason to use a charge controller with a solar power system?

Select	Answer
A	Prevention of battery damage due to overcharge
B	Control of electrolyte levels during battery discharge
C	Matching of day and night charge rates
D	Prevention of battery undercharge

34. - E7E11

Which type of detector is used for demodulating SSB signals?

Select	Answer
A	Product detector
B	Phase detector
C	Discriminator
D	Phase comparator

35. - E7F12

What digital process is applied to I and Q signals in order to recover the baseband modulation information?

Select	Answer
A	Signal conditioning
B	Fast Fourier Transform
C	Quadrature mixing
D	Decimation

36. - E7G04

What is meant by the term op-amp input offset voltage?

Select	Answer
A	The potential between the amplifier input terminals of the op-amp in an open loop condition
B	The differential input voltage needed to bring the open loop output voltage to zero
C	The difference between the output voltage of the op-amp and the input voltage required in the immediately following stage
D	The output voltage of the op-amp minus its input voltage

37. - E7H04

How is positive feedback supplied in a Colpitts oscillator?

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

38. - E8A05

What would be the most accurate way of measuring the RMS voltage of a complex waveform?

Select	Answer
A	By measuring the heating effect in a known resistor
B	By using a grid dip meter
C	By using an absorption wave meter
D	By measuring the voltage with a D'Arsonval meter

39. - E8B11

What is digital time division multiplexing?

Select	Answer
A	Two or more signals are arranged to share discrete time slots of a data transmission
B	Two or more data streams share the same channel by transmitting time of transmission as the sub-carrier
C	Two or more signals are quadrature modulated to increase bandwidth efficiency
D	Two or more data streams are assigned to discrete sub-carriers on an FM transmitter

40. - E8C09

Which is the name of a digital code where each preceding or following character changes by only one bit?

Select	Answer
A	Excess 3 code
B	Gray code
C	Binary Coded Decimal Code
D	Extended Binary Coded Decimal Interchange Code

41. - E8D03

How does the spread spectrum technique of frequency hopping work?

Select	Answer
A	A pseudo-random binary bit stream is used to shift the phase of an RF carrier very rapidly in a particular sequence
B	If interference is detected by the receiver it will signal the transmitter to wait until the frequency is clear
C	If interference is detected by the receiver it will signal the transmitter to change frequencies
D	The frequency of the transmitted signal is changed very rapidly according to a particular sequence also used by the receiving station

42. - E9A12

How much gain does an antenna have compared to a 1/2-wavelength dipole when it has 6 dB gain over an isotropic antenna?

Select	Answer
A	3.85 dB
B	8.15 dB
C	2.79 dB
D	6.0 dB

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	Feed point impedance may become negative
B	The E-field and H-field patterns may reverse
C	Element spacing limits could be exceeded
D	The gain may change depending on frequency

44. - E9C05

What is an OCFD antenna?

Select	Answer
A	A remotely tunable dipole antenna using orthogonally controlled frequency diversity
B	A dipole feed approximately 1/3 the way from one end with a 4:1 balun to provide multiband operation
C	A multiband dipole antenna using one-way circular polarization for frequency diversity
D	An eight band dipole antenna using octophase filters

45. - E9D13

What usually occurs if a Yagi antenna is designed solely for maximum forward gain?

Select	Answer
A	The frequency response is widened over the whole frequency band
B	The front-to-back ratio increases
C	The front-to-back ratio decreases
D	The SWR is reduced

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 omega matching system
B	The stub matching system
C	The delta matching system
D	The gamma matching system

47. - E9F16

Which of the following is a significant difference between foam dielectric coaxial cable and solid dielectric cable, assuming all other parameters are the same?

Select	Answer
A	Foam dielectric has lower safe operating voltage limits
B	Foam dielectric has lower loss per unit of length
C	Foam dielectric has higher velocity factor
D	All of these choices are correct

48. - E9G05

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

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

49. - E9H01

When constructing a Beverage antenna, which of the following factors should be included in the design to achieve good performance at the desired frequency?

Select	Answer
A	It should be one or more wavelengths long
B	Its overall length must not exceed 1/4 wavelength
C	It must be mounted more than 1 wavelength above ground
D	It should be configured as a four-sided loop

50. - E0A02

When evaluating RF exposure levels from your station at a neighbor's home, what must you do?

Select	Answer
A	Advise your neighbors of the results of your tests
B	Make sure signals from your station are less than the controlled MPE limits
C	Make sure signals from your station are less than the uncontrolled MPE limits
D	You need only evaluate exposure levels on your own property

Figure E5-2

Figure E9-3