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

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1. - E1A01

When using a transceiver that displays the carrier frequency of phone signals, which of the following displayed frequencies represents the highest frequency at which a properly adjusted USB emission will be totally within the band?

Select	Answer
A	The exact upper band edge
B	1 kHz below the upper band edge
C	300 Hz below the upper band edge
D	3 kHz below the upper band edge

2. - E1B11

What is the permitted mean power of any spurious emission relative to the mean power of the fundamental emission from a station transmitter or external RF amplifier installed after January 1, 2003 and transmitting on a frequency below 30 MHZ?

Select	Answer
A	At least 73 dB below
B	At least 53 dB below
C	At least 43 dB below
D	At least 63 dB below

3. - E1C13

Which of the following is required in order to operate in accordance with CEPT rules in foreign countries where permitted?

Select	Answer
A	You must append "/CEPT" to your call sign
B	You must bring a copy of FCC Public Notice DA 11-221
C	You must identify in the official language of the country in which you are operating
D	The U.S. embassy must approve of your operation

4. - E1D07

Which amateur service HF bands have frequencies authorized for space stations?

Select	Answer
A	Only the 40 m, 20 m, 17 m, 15 m, 12 m and 10 m bands
B	Only the 40 m, 20 m, 17 m, 15 m and 10 m bands
C	Only the 40 m, 30 m, 20 m, 15 m, 12 m and 10 m bands
D	All HF bands

5. - E1E01

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

Select	Answer
A	4
B	2
C	5
D	3

6. - E1F01

On what frequencies are spread spectrum transmissions permitted?

Select	Answer
A	Only on amateur frequencies above 144 MHz
B	Only on amateur frequencies above 50 MHz
C	Only on amateur frequencies above 222 MHz
D	Only on amateur frequencies above 420 MHz

7. - E2A01

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

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

8. - E2B06

What is vestigial sideband modulation?

Select	Answer
A	Spread spectrum modulation achieved by applying FM modulation following single sideband amplitude modulation
B	Amplitude modulation in which one complete sideband and a portion of the other are transmitted
C	Narrow-band FM modulation achieved by filtering one sideband from the audio before frequency modulating the carrier
D	A type of modulation in which one sideband is inverted

9. - E2C09

What type of equipment is commonly used to implement a ham radio mesh network?

Select	Answer
A	A 440 MHz transceiver with a 9600 baud modem
B	An optical cable connection between the USB ports of 2 separate computers
C	A 2 meter VHF transceiver with a 1200 baud modem
D	A standard wireless router running custom software

10. - E2D13

What type of modulation is used for JT65 contacts?

Select	Answer
A	IEEE 802.11
B	Multi-tone AFSK
C	PSK
D	RTTY

11. - E2E01

Which type of modulation is common for data emissions below 30 MHz?

Select	Answer
A	FSK
B	DTMF tones modulating an FM signal
C	Spread spectrum
D	Pulse modulation

12. - E3A09

Which of the following frequency range is most suited for meteor scatter communications?

Select	Answer
A	10 MHz - 14 MHz
B	28 MHz - 148 MHz
C	220 MHz - 450 MHz
D	1.8 MHz - 1.9 MHz

13. - E3B09

At what time of year is Sporadic E propagation most likely to occur?

Select	Answer
A	Around the equinoxes, especially the spring equinox
B	Around the equinoxes, especially the fall equinox
C	Around the solstices, especially the summer solstice
D	Around the solstices, especially the winter solstice

14. - E3C14

Why does the radio-path horizon distance exceed the geometric horizon?

Select	Answer
A	D-region skip
B	E-region skip
C	Downward bending due to aurora refraction
D	Downward bending due to density variations in the atmosphere

15. - E4A09

When using a computer's soundcard input to digitize signals, what is the highest frequency signal that can be digitized without aliasing?

Select	Answer
A	One-tenth the sample rate
B	The same as the sample rate
C	One-half the sample rate
D	It depends on how the data is stored internally

16. - E4B08

Which of the following is a characteristic of a good DC voltmeter?

Select	Answer
A	High reluctance input
B	Low impedance input
C	Low reluctance input
D	High impedance input

17. - E4C08

An SDR receiver is overloaded when input signals exceed what level?

Select	Answer
A	One-half the maximum sampling buffer size
B	The maximum count value of the analog-to-digital converter
C	One-half the maximum sample rate
D	The reference voltage of the analog-to-digital converter

18. - E4D06

What is the term for unwanted signals generated by the mixing of two or more signals?

Select	Answer
A	Amplifier desensitization
B	Neutralization
C	Adjacent channel interference
D	Intermodulation interference

19. - E4E15

Which of the following can cause shielded cables to radiate or receive interference?

Select	Answer
A	Common mode currents on the shield and conductors
B	Low inductance ground connections at both ends of the shield
C	Use of braided shielding material
D	Tying all ground connections to a common point resulting in differential mode currents in the shield

20. - E5A06

What is the magnitude of the circulating current within the components of a parallel LC circuit at resonance?

Select	Answer
A	It is at a minimum
B	It equals 2 multiplied by Pi, multiplied by frequency, multiplied by inductance
C	It equals 1 divided by the quantity 2 times Pi, multiplied by the square root of inductance L multiplied by capacitance C
D	It is at a maximum

21. - E5B07

What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 500 ohms, R is 1 kilohm, and XL is 250 ohms?

Select	Answer
A	14.0 degrees with the voltage leading the current
B	14.0 degrees with the voltage lagging the current
C	68.2 degrees with the voltage lagging the current
D	68.2 degrees with the voltage leading the current

22. - E5C06

What does the impedance 50-j25 represent?

Select	Answer
A	50 ohms resistance in series with 25 ohms inductive reactance
B	50 ohms resistance in series with 25 ohms capacitive reactance
C	25 ohms resistance in series with 50 ohms inductive reactance
D	25 ohms resistance in series with 50 ohms capacitive reactance

23. - E5D04

Why are short connections necessary at microwave frequencies?

Select	Answer
A	To reduce phase shift along the connection
B	To reduce noise figure
C	Because of ground reflections
D	To increase neutralizing resistance

24. - E6A09

What is a depletion-mode FET?

Select	Answer
A	An FET that exhibits a current flow between source and drain when no gate voltage is applied
B	Any FET for which holes are the majority carriers
C	An FET that has no current flow between source and drain when no gate voltage is applied
D	Any FET without a channel

25. - E6B02

What is an important characteristic of a Schottky diode as compared to an ordinary silicon diode when used as a power supply rectifier?

Select	Answer
A	Controlled reverse avalanche voltage
B	Enhanced carrier retention time
C	Much higher reverse voltage breakdown
D	Less forward voltage drop

26. - E6C13

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	It is totally immune to electrostatic damage
C	All of these choices are correct
D	Its simplicity results in much less expensive devices than standard CMOS

27. - E6D07

What is the usable frequency range of inductors that use toroidal cores, assuming a correct selection of core material for the frequency being used?

Select	Answer
A	From approximately 10 Hz to no more than 3000 kHz
B	From less than 20 Hz to approximately 300 MHz
C	From a few kHz to no more than 30 MHz
D	From about 100 kHz to at least 1000 GHz

28. - E6E02

Which of the following device packages is a through-hole type?

Select	Answer
A	SOT
B	DIP
C	Ball grid array
D	PLCC

29. - E6F08

Why are optoisolators often used in conjunction with solid state circuits when switching 120VAC?

Select	Answer
A	Optoisolators provide impedance matching between the control circuit and power circuit
B	Optoisolators provide a very high degree of electrical isolation between a control circuit and the circuit being switched
C	Optoisolators eliminate the effects of reflected light in the control circuit
D	Optoisolators provide a low impedance link between a control circuit and a power circuit

30. - E7A02

What is the function of a decade counter digital IC?

Select	Answer
A	It decodes a decimal number for display on a seven segment LED display
B	It adds two decimal numbers together
C	It produces one output pulse for every ten input pulses
D	It produces ten output pulses for every input pulse

31. - E7B07

Which of the following is a likely result when a Class C amplifier is used to amplify a single-sideband phone signal?

Select	Answer
A	Signal distortion and excessive bandwidth
B	Signal inversion
C	Increased overall intelligibility
D	Reduced intermodulation products

32. - E7C08

Which of the following factors has the greatest effect in helping determine the bandwidth and response shape of a crystal ladder filter?

Select	Answer
A	The DC voltage applied to the quartz crystal
B	The gain of the RF stage preceding the filter
C	The amplitude of the signals passing through the filter
D	The relative frequencies of the individual crystals

33. - E7D02

What is one characteristic of a switching electronic voltage regulator?

Select	Answer
A	The resistance of a control element is varied in direct proportion to the line voltage or load current
B	It gives a ramp voltage at its output
C	It is generally less efficient than a linear regulator
D	The controlled device's duty cycle is changed to produce a constant average output voltage

34. - E7E10

How does a diode detector function?

Select	Answer
A	By breakdown of the Zener voltage
B	By sensing the change of reactance in the diode with respect to frequency
C	By mixing signals with noise in the transition region of the diode
D	By rectification and filtering of RF signals

35. - E7F03

What type of digital signal processing filter is used to generate an SSB signal?

Select	Answer
A	A Hilbert-transform filter
B	An adaptive filter
C	A notch filter
D	An elliptical filter

36. - E7G08

How does the gain of an ideal operational amplifier vary with frequency?

Select	Answer
A	It decreases linearly with increasing frequency
B	It does not vary with frequency
C	It decreases logarithmically with increasing frequency
D	It increases linearly with increasing frequency

37. - E7H02

Which describes a microphonic?

Select	Answer
A	Excess loading of the microphone by an oscillator
B	Changes in oscillator frequency due to mechanical vibration
C	An IC used for amplifying microphone signals
D	Distortion caused by RF pickup on the microphone cable

38. - E8A13

Which of these methods is commonly used to convert analog signals to digital signals?

Select	Answer
A	Phase reversal
B	Harmonic regeneration
C	Level shifting
D	Sequential sampling

39. - E8B01

What is the term for the ratio between the frequency deviation of an RF carrier wave and the modulating frequency of its corresponding FM-phone signal?

Select	Answer
A	Quieting index
B	Percentage of modulation
C	Modulation index
D	FM compressibility

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	Extended Binary Coded Decimal Interchange Code
D	Binary Coded Decimal Code

41. - E8D09

What is considered a good minimum IMD level for an idling PSK signal?

Select	Answer
A	-30 dB
B	+10 dB
C	-20 dB
D	+15 dB

42. - E9A17

What is the effective radiated power of a repeater station with 200 watts transmitter power output, 2 dB feed line loss, 2.8 dB duplexer loss, 1.2 dB circulator loss, and 7 dBi antenna gain?

Select	Answer
A	159 watts
B	632 watts
C	252 watts
D	63.2 watts

43. - E9B15

What is the front-to-back ratio of the radiation pattern shown in Figure E9-2?

Select	Answer
A	28 dB
B	24 dB
C	15 dB
D	3 dB

44. - E9C07

What is the approximate feed point impedance at the center of a two-wire folded dipole antenna?

Select	Answer
A	300 ohms
B	72 ohms
C	50 ohms
D	450 ohms

45. - E9D01

How does the gain of an ideal parabolic dish antenna change when the operating frequency is doubled?

Select	Answer
A	Gain increases by 3 dB
B	Gain does not change
C	Gain is multiplied by 0.707
D	Gain increases by 6 dB

46. - E9E05

How must the driven element in a 3-element Yagi be tuned to use a hairpin matching system?

Select	Answer
A	The driven element resonance must be lower than the operating frequency
B	The driven element reactance must be inductive
C	The driven element radiation resistance must be higher than the characteristic impedance of the transmission line
D	The driven element reactance must be capacitive

47. - E9F12

What impedance does a 1/4 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	The same as the input impedance to the generator
C	Very high impedance
D	Very low impedance

48. - E9G09

What third family of circles is often added to a Smith chart during the process of solving problems?

Select	Answer
A	Antenna-length circles
B	Standing wave ratio circles
C	Coaxial-length circles
D	Radiation-pattern circles

49. - E9H05

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

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

50. - E0A09

Which insulating material commonly used as a thermal conductor for some types of electronic devices is extremely toxic if broken or crushed and the particles are accidentally inhaled?

Select	Answer
A	Zinc oxide
B	Beryllium Oxide
C	Uranium Hexafluoride
D	Mica

Figure E9-2