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

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1. - E0A07

How may dangerous levels of carbon monoxide from an emergency generator be detected?

Select	Answer
A	Only with a carbon monoxide detector
B	By the odor
C	By the yellowish appearance of the gas
D	Any ordinary smoke detector can be used

2. - E1A05

What is the maximum power output permitted on the 60 meter band?

Select	Answer
A	50 watts PEP effective radiated power relative to an isotropic radiator
B	100 watts PEP effective radiated power relative to the gain of a half-wave dipole
C	100 watts PEP effective radiated power relative to an isotropic radiator
D	50 watts PEP effective radiated power relative to a dipole

3. - E1B06

Which of the following additional rules apply if you are installing an amateur station antenna at a site at or near a public use airport?

Select	Answer
A	You must file an Environmental Impact Statement with the EPA before construction begins
B	You must submit engineering drawings to the FAA
C	You must obtain a construction permit from the airport zoning authority
D	You may have to notify the Federal Aviation Administration and register it with the FCC as required by Part 17 of the FCC rules

4. - E1C14

How long must an operator wait after filing a notification with the Utilities Technology Council (UTC) before operating on the 2200 meter or 630 meter band?

Select	Answer
A	Operators may operate after 30 days, providing they have not been told that their station is within 1 km of PLC systems using those frequencies
B	Operators may not operate until a test signal has been transmitted in coordination with the local power company
C	Operators must not operate until approval is received
D	Operations may commence immediately, and may continue unless interference is reported by the UTC

5. - E1D04

Which of the following is required in the identification transmissions from a balloon-borne telemetry station?

Select	Answer
A	All these choices are correct
B	Call sign
C	The station's six-character Maidenhead grid locator
D	The output power of the balloon transmitter

6. - E1E06

Who is responsible for the proper conduct and necessary supervision during an amateur operator license examination session?

Select	Answer
A	The VE session manager
B	The VEC coordinating the session
C	The FCC
D	Each administering VE

7. - E1F02

What privileges are authorized in the U.S. to persons holding an amateur service license granted by the government of Canada?

Select	Answer
A	None, they must obtain a U.S. license
B	All privileges of the Amateur Extra Class license
C	The operating terms and conditions of the Canadian amateur service license, not to exceed U.S. Amateur Extra Class license privileges
D	Full privileges, up to and including those of the Amateur Extra Class license, on the 80, 40, 20, 15, and 10 meter bands

8. - E2A09

What do the terms L band and S band specify regarding satellite communications?

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

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

10. - E2C09

What type of equipment is commonly used to implement an amateur radio mesh network?

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

11. - E2D08

What type of packet frame is used to transmit APRS beacon data?

Select	Answer
A	Unnumbered Information
B	Disconnect
C	Connect
D	Acknowledgement

12. - E2E09

Which of the following HF digital modes uses variable-length coding for bandwidth efficiency?

Select	Answer
A	PSK31
B	PACTOR
C	RTTY
D	MT63

13. - 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 F2 layer
B	The F1 layer
C	The D layer
D	The E layer

14. - E3B07

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

Select	Answer
A	They become elliptically polarized
B	They become depolarized
C	They are bent toward the magnetic poles
D	They become phase locked

15. - E3C08

What does the space weather term G5 mean?

Select	Answer
A	Moderate solar wind
B	An extreme geomagnetic storm
C	Very low solar activity
D	Waning sunspot numbers

16. - E4A04

How is the compensation of an oscilloscope probe typically adjusted?

Select	Answer
A	A square wave is displayed and the probe is adjusted until the horizontal portions of the displayed wave are as nearly flat as possible
B	A high frequency sine wave is displayed and the probe is adjusted for maximum amplitude
C	A frequency standard is displayed and the probe is adjusted until the deflection time is accurate
D	A DC voltage standard is displayed and the probe is adjusted until the displayed voltage is accurate

17. - E4B01

Which of the following factors most affects the accuracy of a frequency counter?

Select	Answer
A	Input attenuator accuracy
B	Decade divider accuracy
C	Time base accuracy
D	Temperature coefficient of the logic

18. - E4C02

Which of the following receiver circuits can be effective in eliminating interference from strong out-of-band signals?

Select	Answer
A	A properly adjusted product detector
B	A notch filter
C	A narrow IF filter
D	A front-end filter or pre-selector

19. - E4D05

What transmitter frequencies would cause an intermodulation-product signal in a receiver tuned to 146.70 MHz when a nearby station transmits on 146.52 MHz?

Select	Answer
A	173.35 MHz and 139.40 MHz
B	146.34 MHz and 146.61 MHz
C	146.88 MHz and 146.34 MHz
D	146.10 MHz and 147.30 MHz

20. - E4E04

How can conducted and radiated noise caused by an automobile alternator be suppressed?

Select	Answer
A	By installing a high-pass filter in series with the radio's power lead and a low-pass filter in parallel with the field lead
B	By connecting the radio's power leads directly to the battery and by installing coaxial capacitors in line with the alternator leads
C	By installing a noise suppression resistor and a blocking capacitor in both leads
D	By installing filter capacitors in series with the DC power lead and a blocking capacitor in the field lead

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 in phase
D	The voltage and current are 180 degrees out of phase

22. - E5B02

What letter is commonly used to represent susceptance?

Select	Answer
A	X
B	B
C	G
D	Y

23. - E5C09

When using rectangular coordinates to graph the impedance of a circuit, what do the axes represent?

Select	Answer
A	The X axis represents the phase angle and the Y axis represents the magnitude
B	The X axis represents the reactive component and the Y axis represents the resistive component
C	The X axis represents the resistive component and the Y axis represents the reactive component
D	The X axis represents the magnitude and the Y axis represents the phase angle

24. - E5D15

What is the power factor of an RL circuit having a 45-degree phase angle between the voltage and the current?

Select	Answer
A	0.707
B	0.866
C	1.0
D	0.5

25. - E6A05

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	They are both low impedance
B	An FET has lower input impedance
C	They are both high impedance
D	An FET has higher input impedance

26. - E6B08

Which of the following is a Schottky barrier diode?

Select	Answer
A	PIN junction
B	Thermionic emission diode
C	Electrolytic rectifier
D	Metal-semiconductor junction

27. - E6C09

What is a Programmable Logic Device (PLD)?

Select	Answer
A	Programmable equipment used for testing digital logic integrated circuits
B	A logic circuit that can be modified during use
C	A type of transistor whose gain can be changed by digital logic circuits
D	A programmable collection of logic gates and circuits in a single integrated circuit

28. - E6D07

What is current in the primary winding of a transformer called if no load is attached to the secondary?

Select	Answer
A	Stabilizing current
B	Excitation current
C	Magnetizing current
D	Direct current

29. - E6E10

What advantage does surface-mount technology offer at RF compared to using through-hole components?

Select	Answer
A	Components have less parasitic inductance and capacitance
B	All these choices are correct
C	Shorter circuit-board traces
D	Smaller circuit area

30. - E6F10

What is the most common type of photovoltaic cell used for electrical power generation?

Select	Answer
A	Selenium
B	Copper oxide
C	Cadmium Sulfide
D	Silicon

31. - E7A09

What logical operation is performed by an exclusive NOR gate?

Select	Answer
A	It produces logic 1 at its output if only one input is logic 1
B	It produces logic 0 at its output if only one input is logic 1
C	It produces logic 0 at its output only if all inputs are logic 0
D	It produces logic 1 at its output only if all inputs are logic 1

32. - E7B11

In Figure E7-1, what is the purpose of R3?

Select	Answer
A	Self bias
B	Fixed bias
C	Emitter bypass
D	Output load resistor

33. - E7C07

Which describes a Pi-L-network used for matching a vacuum tube final amplifier to a 50-ohm unbalanced output?

Select	Answer
A	A Phase Inverter Load network
B	A Pi-network with an additional series inductor on the output
C	A matching network in which all components are isolated from ground
D	A network with only three discrete parts

34. - E7D15

What is the purpose of a step-start circuit in a high-voltage power supply?

Select	Answer
A	To provide a dual-voltage output for reduced power applications
B	To compensate for variations of the incoming line voltage
C	To allow for remote control of the power supply
D	To allow the filter capacitors to charge gradually

35. - E7E11

Which type of detector circuit is used for demodulating SSB signals?

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

36. - E7F01

What is meant by direct digital conversion as applied to software defined radios?

Select	Answer
A	Software is converted from source code to object code during operation of the receiver
B	Incoming RF is digitized by an analog-to-digital converter without being mixed with a local oscillator signal
C	Incoming RF is converted to a control voltage for a voltage controlled oscillator
D	A switching mixer is used to generate I and Q signals directly from the RF input

37. - E7G07

What magnitude of voltage gain can be expected from the circuit in Figure E73 when R1 is 10 ohms and RF is 470 ohms?

Select	Answer
A	24
B	0.21
C	47
D	94

38. - E7H15

Which of these functions can be performed by a phase-locked loop?

Select	Answer
A	Photovoltaic conversion, optical coupling
B	Wide-band AF and RF power amplification
C	Comparison of two digital input signals, digital pulse counter
D	Frequency synthesis, FM demodulation

39. - E8A09

How many different input levels can be encoded by an analog-to-digital converter with 8-bit resolution?

Select	Answer
A	8 multiplied by the gain of the input amplifier
B	256
C	256 divided by the gain of the input amplifier
D	8

40. - E8B09

What is deviation ratio?

Select	Answer
A	The ratio of the carrier center frequency to the audio modulating frequency
B	The ratio of the audio modulating frequency to the center carrier frequency
C	The ratio of the highest audio modulating frequency to the average audio modulating frequency
D	The ratio of the maximum carrier frequency deviation to the highest audio modulating frequency

41. - E8C07

What is the bandwidth of a 4800-Hz frequency shift, 9600-baud ASCII FM transmission?

Select	Answer
A	15.36 kHz
B	5.76 kHz
C	9.6 kHz
D	4.8 kHz

42. - E8D08

What parameter evaluates distortion of an AFSK signal caused by excessive input audio levels?

Select	Answer
A	Intermodulation Distortion (IMD)
B	Baud rate
C	Signal-to-noise ratio
D	Repeat Request Rate (RRR)

43. - E9A03

What is the radiation resistance of an antenna?

Select	Answer
A	The specific impedance of the antenna
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 resistance in the atmosphere that an antenna must overcome to be able to radiate a signal

44. - E9B04

What is the front-to-back ratio of the radiation pattern shown in Figure E92?

Select	Answer
A	15 dB
B	28 dB
C	38 dB
D	3 dB

45. - E9C03

What is the radiation pattern of two 1/4-wavelength vertical antennas spaced 1/2-wavelength apart and fed in phase?

Select	Answer
A	Omni-directional
B	A Figure-8 end-fire along the axis of the array
C	Cardioid
D	A Figure-8 broadside to the axis of the array

46. - E9D07

What is an advantage of using top loading in a shortened HF vertical antenna?

Select	Answer
A	Improved radiation efficiency
B	Lower Q
C	Greater structural strength
D	Higher losses

47. - E9E10

Which of these choices is an effective way to match an antenna with a 100-ohm feed point impedance to a 50-ohm coaxial cable feed line?

Select	Answer
A	Insert a 1/2 wavelength piece of 300-ohm twinlead in series between the antenna terminals and the 50-ohm feed cable
B	Connect a 1/4-wavelength open stub of 300-ohm twinlead in parallel with the coaxial feed line where it connects to the antenna
C	Insert a 1/4-wavelength piece of 75-ohm coaxial cable transmission line in series between the antenna terminals and the 50-ohm feed cable
D	Connect a 1/2 wavelength shorted stub of 75-ohm cable in parallel with the 50-ohm cable where it attaches to the antenna

48. - E9F08

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

49. - E9G01

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

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

50. - E9H11

What feature of a cardioid pattern antenna makes it useful for direction finding?

Select	Answer
A	A very sharp peak
B	Broadband response
C	A very sharp single null
D	High radiation angle

Figure E7-1