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

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1. - E0A06

Why are there separate electric (E) and magnetic (H) field MPE limits?

SelectAnswer
AGround reflections and scattering make the field strength vary with location
BThe body reacts to electromagnetic radiation from both the E and H fields
CE field and H field radiation intensity peaks can occur at different locations
DAll these choices are correct

2. - E1A02

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

SelectAnswer
A1 kHz above the lower band edge
B3 kHz above the lower band edge
C300 Hz above the lower band edge
DThe exact lower band edge

3. - E1B09

Which amateur stations may be operated under RACES rules?

SelectAnswer
AOnly those club stations licensed to Amateur Extra Class operators
BAny FCC-licensed amateur station certified by the responsible civil defense organization for the area served
CAny FCC-licensed amateur station participating in the Military Auxiliary Radio System (MARS)
DAny FCC-licensed amateur station except a Technician Class

4. - E1C06

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

SelectAnswer
AYou must append "/CEPT" to your call sign
BThe U.S. embassy must approve of your operation
CYou must bring a copy of FCC Public Notice DA 16-1048
DYou must identify in the official language of the country in which you are operating

5. - E1D07

Which HF amateur bands have frequencies authorized for space stations?

SelectAnswer
AAll HF bands
BOnly the 40, 20, 17, 15, 12, and 10 meter bands
COnly the 40, 30, 20, 15, 12, and 10 meter bands
DOnly the 40, 20, 17, 15, and 10 meter bands

6. - E1E09

What may be the penalty for a VE who fraudulently administers or certifies an examination?

SelectAnswer
ARevocation of the VE's amateur station license grant and the suspension of the VE's amateur operator license grant
BAll these choices are correct
CA fine of up to $1000 per occurrence
DA sentence of up to one year in prison

7. - E1F08

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

SelectAnswer
ACommunications transmitted for hire or material compensation, except as otherwise provided in the rules
BCommunications that have political content, except as allowed by the Fairness Doctrine
CCommunications in a language other than English
DCommunications that have religious content

8. - E2A07

Which of the following types of signals can be relayed through a linear transponder?

SelectAnswer
APSK and packet
BFM and CW
CAll these choices are correct
DSSB and SSTV

9. - E2B08

What technique allows commercial analog TV receivers to be used for fast-scan TV operations on the 70 cm band?

SelectAnswer
AUsing USB and demodulating the signal with a computer sound card
BUsing converted satellite TV dishes
CTransmitting on the abandoned TV channel 2
DTransmitting on channels shared with cable TV

10. - E2C01

What indicator is required to be used by U.S.-licensed operators when operating a station via remote control and the remote transmitter is located in the U.S.?

SelectAnswer
ANo additional indicator is required
B/R# where # is the district of the remote station
C/ followed by the USPS two-letter abbreviation for the state in which the remote station is located
D/ followed by the ARRL Section of the remote station

11. - E2D01

Which of the following digital modes is designed for meteor scatter communications?

SelectAnswer
AMSK144
BHellschreiber
CAPRS
DWSPR

12. - E2E13

Which of these digital modes has the fastest data throughput under clear communication conditions?

SelectAnswer
APSK31
BAMTOR
C300 baud packet
D170 Hz shift, 45 baud RTTY

13. - E3A13

Which of these emission modes is best for auroral propagation?

SelectAnswer
ASSB
BRTTY
CCW
DFM

14. - E3B01

What is transequatorial propagation?

SelectAnswer
APropagation between points located on the magnetic equator
BPropagation between a point on the equator and its antipodal point
CPropagation between points at the same latitude
DPropagation between two mid-latitude points at approximately the same distance north and south of the magnetic equator

15. - E3C04

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

SelectAnswer
ACritical frequency for vertical transmissions
BDirection and strength of the interplanetary magnetic field
CGeomagnetic field stability
DDuration of long-delayed echoes

16. - E4A01

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

SelectAnswer
AQ of the circuit
BSampling rate of the analog-to-digital converter
CAmount of memory
DAll these choices are correct

17. - E4B08

Which of the following can be used to measure the Q of a series-tuned circuit?

SelectAnswer
AThe bandwidth of the circuit's frequency response
BThe frequency shift
CThe resonant frequency of the circuit
DThe inductance to capacitance ratio

18. - E4C12

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

SelectAnswer
AAnti-aliasing input filter bandwidth
BAnalog-to-digital converter sample width in bits
CRAM speed used for data storage
DCPU register width in bits

19. - E4D12

What is the term for the reduction in receiver sensitivity caused by a strong signal near the received frequency?

SelectAnswer
ASquelch gain rollback
BDesensitization
CCross-modulation interference
DQuieting

20. - E4E11

What could cause local AM broadcast band signals to combine to generate spurious signals in the MF or HF bands?

SelectAnswer
ANearby corroded metal joints are mixing and re-radiating the broadcast signals
BYour station receiver IF amplifier stage is defective
COne or more of the broadcast stations is transmitting an over-modulated signal
DYou are receiving skywave signals from a distant station

21. - E5A14

What is the resonant frequency of an RLC circuit if R is 22 ohms, L is 50 microhenries and C is 40 picofarads?

SelectAnswer
A44.72 MHz
B22.36 MHz
C1.78 MHz
D3.56 MHz

22. - E5B10

What is the relationship between the AC current through an inductor and the voltage across an inductor?

SelectAnswer
AVoltage and current are 180 degrees out of phase
BVoltage and current are in phase
CCurrent leads voltage by 90 degrees
DVoltage leads current by 90 degrees

23. - E5C08

What coordinate system is often used to display the phase angle of a circuit containing resistance, inductive and/or capacitive reactance?

SelectAnswer
AMaidenhead grid
BElliptical coordinates
CPolar coordinates
DFaraday grid

24. - E5D11

What is the power factor of an RL circuit having a 60-degree phase angle between the voltage and the current?

SelectAnswer
A1.414
B0.5
C1.73
D0.866

25. - E6A09

What is a depletion-mode FET?

SelectAnswer
AAn FET that has no current flow between source and drain when no gate voltage is applied
BAny FET without a channel
CAny FET for which holes are the majority carriers
DAn FET that exhibits a current flow between source and drain when no gate voltage is applied

26. - E6B05

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

SelectAnswer
ALow junction capacitance
BExtremely high reverse breakdown voltage
CReverse bias controls its forward voltage drop
DAbility to dissipate large amounts of power

27. - E6C04

Which of the following is an advantage of BiCMOS logic?

SelectAnswer
AIts simplicity results in much less expensive devices than standard CMOS
BIt is immune to electrostatic damage
CAll these choices are correct
DIt has the high input impedance of CMOS and the low output impedance of bipolar transistors

28. - E6D08

What is one reason for using powdered-iron cores rather than ferrite cores in an inductor?

SelectAnswer
APowdered-iron cores use smaller diameter wire for the same inductance
BPowdered-iron cores generally maintain their characteristics at higher currents
CPowdered-iron cores generally require fewer turns to produce a given inductance
DPowdered-iron cores generally have greater initial permeability

29. - E6E11

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

SelectAnswer
ALow leakage doubly insulated package
BA total of two rows of connecting pins placed on opposite sides of the package (Dual In-line Package)
CTwo chips in each package (Dual In Package)
DPackage mounts in a direct inverted position

30. - E6F04

What is the photovoltaic effect?

SelectAnswer
AThe conversion of light to electrical energy
BThe tendency of a battery to discharge when exposed to light
CThe conversion of electrical energy to mechanical energy
DThe conversion of voltage to current when exposed to light

31. - E7A06

What is a characteristic of a monostable multivibrator?

SelectAnswer
AIt produces a continuous square wave oscillating between 1 and 0
BIt switches momentarily to the opposite binary state and then returns to its original state after a set time
CIt maintains a constant output voltage, regardless of variations in the input voltage
DIt stores one bit of data in either a 0 or 1 state

32. - E7B15

What is one way to prevent thermal runaway in a bipolar transistor amplifier?

SelectAnswer
ASelect transistors with high beta
BNeutralization
CUse a resistor in series with the emitter
DAll these choices are correct

33. - E7C08

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

SelectAnswer
AThe amplitude of the signals passing through the filter
BThe DC voltage applied to the quartz crystal
CThe relative frequencies of the individual crystals
DThe gain of the RF stage preceding the filter

34. - E7D01

How does a linear electronic voltage regulator work?

SelectAnswer
AThe conduction of a control element is varied to maintain a constant output voltage
BIt eliminates the need for a pass transistor
CIt has a ramp voltage as its output
DThe control element duty cycle is proportional to the line or load conditions

35. - E7E06

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

SelectAnswer
ATo reduce impulse noise reception
BFor higher efficiency
CFor compatibility with transmitters using phase modulation
DTo remove third-order distortion products

36. - E7F07

What function is performed by a Fast Fourier Transform?

SelectAnswer
AConverting digital signals to analog form
BConverting 8-bit data to 16-bit data
CConverting digital signals from the time domain to the frequency domain
DConverting analog signals to digital form

37. - E7G08

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

SelectAnswer
AIt decreases linearly with increasing frequency
BIt does not vary with frequency
CIt increases linearly with increasing frequency
DIt decreases logarithmically with increasing frequency

38. - E7H15

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

SelectAnswer
AWide-band AF and RF power amplification
BPhotovoltaic conversion, optical coupling
CFrequency synthesis, FM demodulation
DComparison of two digital input signals, digital pulse counter

39. - E8A06

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

SelectAnswer
A25 to 1
B100 to 1
C1 to 1
D2.5 to 1

40. - E8B08

What describes Orthogonal Frequency Division Multiplexing?

SelectAnswer
AA frequency modulation technique that uses non-harmonically related frequencies
BA bandwidth compression technique using Fourier transforms
CA digital modulation technique using subcarriers at frequencies chosen to avoid intersymbol interference
DA digital mode for narrow-band, slow-speed transmissions

41. - E8C11

What is the relationship between symbol rate and baud?

SelectAnswer
AThey are the same
BBaud is twice the symbol rate
CSymbol rate is only used for packet-based modes
DBaud is only used for RTTY

42. - E8D02

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

SelectAnswer
ADirect sequence
BFrequency hopping
CPhase compandored spread spectrum
DBinary phase-shift keying

43. - E9A06

What is the effective radiated power relative to a dipole of a repeater station with 200 watts transmitter power output, 4 dB feed line loss, 3.2 dB duplexer loss, 0.8 dB circulator loss, and 10 dBd antenna gain?

SelectAnswer
A317 watts
B2000 watts
C126 watts
D300 watts

44. - E9B11

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

SelectAnswer
AThe antenna will become mechanically unstable
BGround conductivity will not be accurately modeled
CThe computed feed point impedance may be incorrect
DThe resulting design will favor radiation of harmonic energy

45. - E9C07

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

SelectAnswer
A50 ohms
B300 ohms
C450 ohms
D72 ohms

46. - E9D05

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

SelectAnswer
AThe front-to-back ratio increases
BThe front-to-back ratio decreases
CThe frequency response is widened over the whole frequency band
DThe SWR is reduced

47. - E9E09

Which of the following is used to shunt-feed a grounded tower at its base?

SelectAnswer
AHairpin match
BGamma match
CAll these choices are correct
DDouble-bazooka match

48. - E9F04

What impedance does a 1/2-wavelength transmission line present to a generator when the line is shorted at the far end?

SelectAnswer
AThe same as the output impedance of the generator
BVery low impedance
CVery high impedance
DThe same as the characteristic impedance of the line

49. - E9G11

How are the wavelength scales on a Smith chart calibrated?

SelectAnswer
AIn fractions of transmission line electrical frequency
BIn fractions of antenna electrical wavelength
CIn fractions of transmission line electrical wavelength
DIn fractions of antenna electrical frequency

50. - E9H11

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

SelectAnswer
AA very sharp peak
BHigh radiation angle
CBroadband response
DA very sharp single null