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

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1. - E0A10

What toxic material may be present in some electronic components such as high voltage capacitors and transformers?

Select	Answer
A	Polychlorinated biphenyls
B	Polyethylene
C	Polymorphic silicon
D	Polytetrafluoroethylene

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

3. - E1B04

What must be done before placing an amateur station within an officially designated wilderness area or wildlife preserve, or an area listed in the National Register of Historic Places?

Select	Answer
A	An Environmental Assessment must be submitted to the FCC
B	A letter of intent must be filed with the Environmental Protection Agency
C	A form FSD-15 must be submitted to the Department of the Interior
D	A proposal must be submitted to the National Park Service

4. - E1C06

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 bring a copy of FCC Public Notice DA 16-1048
B	You must append "/CEPT" to your call sign
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

5. - E1D10

Which amateur stations are eligible to be telecommand stations of space stations (subject to the privileges of the class of operator license held by the control operator of the station)?

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

6. - E1E04

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

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

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

8. - E2A02

Which of the following occurs when a satellite is using an inverting linear transponder?

Select	Answer
A	Signal position in the band is reversed
B	Upper sideband on the uplink becomes lower sideband on the downlink, and vice versa
C	Doppler shift is reduced because the uplink and downlink shifts are in opposite directions
D	All these choices are correct

9. - E2B02

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

Select	Answer
A	60
B	30
C	1080
D	525

10. - E2C02

Which of the following best describes the term self-spotting? in connection with HF contest operating?

Select	Answer
A	The acceptable practice of manually posting the call signs of stations on a spotting network
B	A manual technique for rapidly zero beating or tuning to a station's frequency before calling that station
C	An automatic method for rapidly zero beating or tuning to a station's frequency before calling that station
D	The often-prohibited practice of posting one's own call sign and frequency on a spotting network

11. - E2D07

What digital protocol is used by APRS?

Select	Answer
A	PACTOR
B	802.11
C	AMTOR
D	AX.25

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	First Error Correction
D	Forward Error Correction

13. - E3A06

What might help to restore contact when DX signals become too weak to copy across an entire HF band a few hours after sunset?

Select	Answer
A	Switch to a lower frequency HF band
B	Wait 90 minutes or so for the signal degradation to pass
C	Switch to a higher frequency HF band
D	Wait 24 hours before attempting another communication on the band

14. - E3B03

What is the best time of day for transequatorial propagation?

Select	Answer
A	Late at night
B	Afternoon or early evening
C	Noon
D	Morning

15. - E3C08

What does the space weather term G5 mean?

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

16. - E4A01

Which of the following limits the highest frequency signal that can be accurately displayed on a digital oscilloscope?

Select	Answer
A	Q of the circuit
B	Sampling rate of the analog-to-digital converter
C	Amount of memory
D	All these choices are correct

17. - E4B10

Which of the following methods measures intermodulation distortion in an SSB transmitter?

Select	Answer
A	Modulate the transmitter using two AF signals having non-harmonically related frequencies and observe the RF output with a spectrum analyzer
B	Modulate the transmitter using two AF signals having harmonically related frequencies and observe the RF output with a peak reading wattmeter
C	Modulate the transmitter using two RF signals having non-harmonically related frequencies and observe the RF output with a spectrum analyzer
D	Modulate the transmitter using two RF signals having harmonically related frequencies and observe the RF output with a logic analyzer

18. - E4C08

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

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

19. - E4D10

What does a third-order intercept level of 40 dBm mean with respect to receiver performance?

Select	Answer
A	Signals less than 40 dBm will not generate audible third-order intermodulation products
B	The receiver can tolerate signals up to 40 dB above the noise floor without producing third-order intermodulation products
C	A pair of 1 mW input signals will produce a third-order intermodulation product that is 40 dB stronger than the input signal
D	A pair of 40 dBm input signals will theoretically generate a third-order intermodulation product that has the same output amplitude as either of the input signals

20. - E4E06

What is one type of electrical interference that might be caused by a nearby personal computer?

Select	Answer
A	The appearance of unstable modulated or unmodulated signals at specific frequencies
B	A loud AC hum in the audio output of your station receiver
C	A whining type noise that continually pulses off and on
D	A clicking noise at intervals of a few seconds

21. - E5A02

What is resonance in an LC or RLC circuit?

Select	Answer
A	The lowest frequency that will pass current
B	The frequency at which the reactive impedance equals the resistive impedance
C	The highest frequency that will pass current
D	The frequency at which the capacitive reactance equals the inductive reactance

22. - E5B06

What is susceptance?

Select	Answer
A	The magnetic impedance of a circuit
B	A measure of the efficiency of a transformer
C	The imaginary part of admittance
D	The ratio of magnetic field to electric field

23. - E5C06

What does the impedance 50-j25 represent?

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

24. - E5D05

What is the power factor of an RL circuit having a 30-degree phase angle between the voltage and the current?

Select	Answer
A	0.577
B	0.866
C	1.73
D	0.5

25. - E6A06

What is the beta of a bipolar junction transistor?

Select	Answer
A	The frequency at which the current gain is reduced to 0.707
B	The switching speed
C	The breakdown voltage of the base to collector junction
D	The change in collector current with respect to base current

26. - E6B05

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

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

27. - E6C07

What best describes a pull-up or pull-down resistor?

Select	Answer
A	A resistor that ensures that an oscillator frequency does not drift
B	A resistor connected to the positive or negative supply line used to establish a voltage when an input or output is an open circuit
C	A resistor connected to an op-amp output that prevents signals from exceeding the power supply voltage
D	A resistor in a keying circuit used to reduce key clicks

28. - E6D07

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

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

29. - E6E01

Why is gallium arsenide (GaAs) useful for semiconductor devices operating at UHF and higher frequencies?

Select	Answer
A	Higher noise figures
B	Lower transconductance
C	Lower junction voltage drop
D	Higher electron mobility

30. - E6F05

Which describes an optical shaft encoder?

Select	Answer
A	A digital encryption device often used to encrypt spacecraft control signals
B	A device that detects rotation of a control by interrupting a light source with a patterned wheel
C	A device for generating RTTY signals by means of a rotating light source
D	A device that measures the strength of a beam of light using analog to digital conversion

31. - E7A07

What logical operation does a NAND gate perform?

Select	Answer
A	It produces logic 0 at its output only when all inputs are logic 1
B	It produces logic 0 at its output only when all inputs are logic 0
C	It produces logic 0 at its output if some but not all inputs are logic 1
D	It produces logic 1 at its output only when all inputs are logic 1

32. - E7B04

Where on the load line of a Class A common emitter amplifier would bias normally be set?

Select	Answer
A	Approximately halfway between saturation and cutoff
B	At a point where the bias resistor equals the load resistor
C	At a point where the load line intersects the zero bias current curve
D	Where the load line intersects the voltage axis

33. - E7C06

What are the distinguishing features of an elliptical filter?

Select	Answer
A	Gradual passband rolloff with minimal stop band ripple
B	Extremely flat response over its pass band with gradually rounded stop band corners
C	Gradual passband rolloff with extreme stop band ripple
D	Extremely sharp cutoff with one or more notches in the stop band

34. - E7D15

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

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

35. - E7E10

How does a diode envelope detector function?

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

36. - E7F05

How frequently must an analog signal be sampled by an analog-to-digital converter so that the signal can be accurately reproduced?

Select	Answer
A	At least twice the rate of the highest frequency component of the signal
B	At least half the rate of the highest frequency component of the signal
C	At the same rate as the highest frequency component of the signal
D	At four times the rate of the highest frequency component of the signal

37. - E7G02

What is ringing in a filter?

Select	Answer
A	Partial cancellation of the signal over a range of frequencies
B	An echo caused by a long time delay
C	Undesired oscillations added to the desired signal
D	A reduction in high frequency response

38. - E7H09

What type of frequency synthesizer circuit uses a phase accumulator, lookup table, digital to analog converter, and a low-pass anti-alias filter?

Select	Answer
A	A phase-locked loop synthesizer
B	A hybrid synthesizer
C	A direct digital synthesizer
D	A diode-switching matrix synthesizer

39. - E8A06

What is the approximate ratio of PEP-to-average power in a typical single-sideband phone signal?

Select	Answer
A	1 to 1
B	100 to 1
C	2.5 to 1
D	25 to 1

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	1000
D	3

41. - E8C10

How may data rate be increased without increasing bandwidth?

Select	Answer
A	Using a more efficient digital code
B	Using forward error correction
C	It is impossible
D	Increasing analog-to-digital conversion resolution

42. - E8D06

What is the advantage of including parity bits in ASCII characters?

Select	Answer
A	Some types of errors can be detected
B	The signal can overpower interfering signals
C	Faster transmission rate
D	Foreign language characters can be sent

43. - E9A07

What is the effective isotropic 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

44. - E9B11

What is a disadvantage of decreasing the number of wire segments in an antenna model below 10 segments per half-wavelength?

Select	Answer
A	The resulting design will favor radiation of harmonic energy
B	The antenna will become mechanically unstable
C	Ground conductivity will not be accurately modeled
D	The computed feed point impedance may be incorrect

45. - E9C08

What is a folded dipole antenna?

Select	Answer
A	A dipole configured to provide forward gain
B	A dipole one-quarter wavelength long
C	A type of ground-plane antenna
D	A half-wave dipole with an additional parallel wire connecting its two ends

46. - E9D04

Why should an HF mobile antenna loading coil have a high ratio of reactance to resistance?

Select	Answer
A	To lower the radiation angle
B	To swamp out harmonics
C	To minimize losses
D	To minimize the Q

47. - E9E08

What is a use for a Wilkinson divider?

Select	Answer
A	It divides the operating frequency of a transmitter signal so it can be used on a lower frequency band
B	It is used to feed low-impedance loads from a high-impedance source
C	It is used to feed high-impedance antennas from a low-impedance source
D	It is used to divide power equally between two 50-ohm loads while maintaining 50-ohm input impedance

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

49. - E9G10

What do the arcs on a Smith chart represent?

Select	Answer
A	SWR
B	Points with constant resistance
C	Frequency
D	Points with constant reactance

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	High radiation angle
D	A very sharp single null