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?

Select	Answer
A	All these choices are correct
B	Ground reflections and scattering make the field strength vary with location
C	E field and H field radiation intensity peaks can occur at different locations
D	The body reacts to electromagnetic radiation from both the E and H fields

2. - E1A11

Which of the following describes authorization or licensing required when operating an amateur station aboard a U.S.-registered vessel in international waters?

Select	Answer
A	Only General Class or higher amateur licenses
B	Any FCC-issued amateur license
C	Any amateur license with an FCC Marine or Aircraft endorsement
D	An unrestricted Radiotelephone Operator Permit

3. - E1B02

Which of the following is an acceptable bandwidth for Digital Radio Mondiale (DRM) based voice or SSTV digital transmissions made on the HF amateur bands?

Select	Answer
A	10 kHz
B	20 kHz
C	3 kHz
D	15 kHz

4. - E1C12

On what portion of the 630 meter band are phone emissions permitted?

Select	Answer
A	None
B	Only the bottom 3 kHz
C	The entire band
D	Only the top 3 kHz

5. - E1D09

Which UHF amateur bands have frequencies authorized for space stations?

Select	Answer
A	33 cm and 13 cm
B	70 cm only
C	70 cm and 13 cm
D	70 cm and 33 cm

6. - E1E08

To which of the following examinees may a VE not administer an examination?

Select	Answer
A	All these choices are correct
B	Employees of the VE
C	Friends of the VE
D	Relatives of the VE as listed in the FCC rules

7. - E1F10

Who may be the control operator of an auxiliary station?

Select	Answer
A	Any licensed amateur operator
B	Only General, Advanced or Amateur Extra Class operators
C	Only Amateur Extra Class operators
D	Only Technician, General, Advanced or Amateur Extra Class operators

8. - E2A08

Why should effective radiated power to a satellite that uses a linear transponder be limited?

Select	Answer
A	To prevent creating errors in the satellite telemetry
B	To avoid interfering with terrestrial QSOs
C	To prevent the satellite from emitting out-of-band signals
D	To avoid reducing the downlink power to all other users

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

10. - E2C12

What technique do individual nodes use to form a mesh network?

Select	Answer
A	Acting as store-and-forward digipeaters
B	Forward error correction and Viterbi codes
C	Discovery and link establishment protocols
D	Custom code plugs for the local trunking systems

11. - E2D03

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

Select	Answer
A	JT65
B	MSK144
C	Olivia
D	PACTOR III

12. - E2E03

How is the timing of FT4 contacts organized?

Select	Answer
A	Stations take turns on alternate days
B	It depends on the lunar phase
C	Alternating transmissions at 7.5 second intervals
D	By exchanging ACK/NAK packets

13. - E3A07

Atmospheric ducts capable of propagating microwave signals often form over what geographic feature?

Select	Answer
A	Urban areas
B	Bodies of water
C	Mountain ranges
D	Forests

14. - E3B06

Which of the following amateur bands most frequently provides long-path propagation?

Select	Answer
A	6 meters
B	80 meters
C	20 meters
D	10 meters

15. - E3C13

What type of polarization is best for ground-wave propagation?

Select	Answer
A	Horizontal
B	Vertical
C	Circular
D	Elliptical

16. - E4A11

How should an antenna analyzer be connected when measuring antenna resonance and feed point impedance?

Select	Answer
A	Connect the antenna feed line directly to the analyzer's connector
B	Connect the analyzer via a high-impedance transformer to the antenna
C	Loosely couple the analyzer near the antenna base
D	Loosely couple the antenna and a dummy load to the analyzer

17. - E4B04

Which S parameter represents input port return loss or reflection coefficient (equivalent to VSWR)?

Select	Answer
A	S12
B	S21
C	S11
D	S22

18. - E4C04

What is the noise figure of a receiver?

Select	Answer
A	The ratio of atmospheric noise to phase noise
B	The ratio of the noise bandwidth in hertz to the theoretical bandwidth of a resistive network
C	The ratio in dB of the noise generated by the receiver to the theoretical minimum noise
D	The ratio of thermal noise to atmospheric noise

19. - E4D01

What is meant by the blocking dynamic range of a receiver?

Select	Answer
A	The minimum difference in dB between the levels of two FM signals that will cause one signal to block the other
B	The difference in dB between the noise floor and the level of an incoming signal that will cause 1 dB of gain compression
C	The minimum difference in dB between two signals which produce third-order intermodulation products greater than the noise floor
D	The difference in dB between the noise floor and the third-order intercept point

20. - E4E02

Which of the following types of noise can often be reduced with a digital signal processing noise filter?

Select	Answer
A	Power line noise
B	All these choices are correct
C	Ignition noise
D	Broadband white noise

21. - E5A12

What is the half-power bandwidth of a resonant circuit that has a resonant frequency of 3.7 MHz and a Q of 118?

Select	Answer
A	31.4 kHz
B	436.6 kHz
C	15.7 kHz
D	218.3 kHz

22. - E5B04

What is the time constant of a circuit having two 220-microfarad capacitors and two 1-megohm resistors, all in parallel?

Select	Answer
A	110 seconds
B	55 seconds
C	220 seconds
D	440 seconds

23. - E5C03

Which of the following represents an inductive reactance in polar coordinates?

Select	Answer
A	A negative magnitude
B	A positive phase angle
C	A negative phase angle
D	A positive magnitude

24. - E5D12

How many watts are consumed in a circuit having a power factor of 0.2 if the input is 100 VAC at 4 amperes?

Select	Answer
A	400 watts
B	80 watts
C	50 watts
D	2000 watts

25. - E6A04

What is the name given to an impurity atom that adds holes to a semiconductor crystal structure?

Select	Answer
A	Donor impurity
B	N-type impurity
C	Insulator impurity
D	Acceptor impurity

26. - E6B05

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

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

27. - E6C07

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

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

28. - E6D01

Why should core saturation of an impedance matching transformer be avoided?

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

29. - E6E04

Which is the most common input and output impedance of circuits that use MMICs?

Select	Answer
A	450 ohms
B	300 ohms
C	10 ohms
D	50 ohms

30. - E6F01

What absorbs the energy from light falling on a photovoltaic cell?

Select	Answer
A	Holes
B	Electrons
C	Protons
D	Photons

31. - E7A08

What logical operation does an OR gate perform?

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

32. - E7B16

What is the effect of intermodulation products in a linear power amplifier?

Select	Answer
A	All these choices are correct
B	Creation of parasitic oscillations
C	Low efficiency
D	Transmission of spurious signals

33. - E7C01

How are the capacitors and inductors of a low-pass filter Pi-network arranged between the network's input and output?

Select	Answer
A	Two inductors are in series between the input and output, and a capacitor is connected between the two inductors and ground
B	An inductor is connected between the input and ground, another inductor is connected between the output and ground, and a capacitor is connected between the input and output
C	A capacitor is connected between the input and ground, another capacitor is connected between the output and ground, and an inductor is connected between input and output
D	Two capacitors are in series between the input and output, and an inductor is connected between the two capacitors and ground

34. - E7D08

What type of circuit is shown in Figure E7-2?

Select	Answer
A	Linear voltage regulator
B	Switching voltage regulator
C	Grounded emitter amplifier
D	Monostable multivibrator

35. - E7E10

How does a diode envelope detector function?

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

36. - E7F03

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

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

37. - E7G09

What will be the output voltage of the circuit shown in Figure E7-3 if R1 is 1000 ohms, RF is 10,000 ohms, and 0.23 volts DC is applied to the input?

Select	Answer
A	-2.3 volts
B	0.23 volts
C	-0.23 volts
D	2.3 volts

38. - E7H03

How is positive feedback supplied in a Hartley oscillator?

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

39. - E8A07

What determines the PEP-to-average power ratio of a single-sideband phone signal?

Select	Answer
A	Speech characteristics
B	Amplifier gain
C	The frequency of the modulating signal
D	The degree of carrier suppression

40. - E8B08

What describes Orthogonal Frequency Division Multiplexing?

Select	Answer
A	A frequency modulation technique that uses non-harmonically related frequencies
B	A bandwidth compression technique using Fourier transforms
C	A digital modulation technique using subcarriers at frequencies chosen to avoid intersymbol interference
D	A digital mode for narrow-band, slow-speed transmissions

41. - E8C04

What technique minimizes the bandwidth of a PSK31 signal?

Select	Answer
A	Use of sinusoidal data pulses
B	Use of trapezoidal data pulses
C	Reed-Solomon character encoding
D	Zero-sum character encoding

42. - E8D04

What is the primary effect of extremely short rise or fall time on a CW signal?

Select	Answer
A	More difficult to copy
B	The generation of RF harmonics
C	Limits data speed
D	The generation of key clicks

43. - E9A10

Which of the following improves the efficiency of a ground-mounted quarter-wave vertical antenna?

Select	Answer
A	Installing a radial system
B	All these choices are correct
C	Isolating the coax shield from ground
D	Shortening the radiating element

44. - E9B09

What type of computer program technique is commonly used for modeling antennas?

Select	Answer
A	Method of Moments
B	Graphical analysis
C	Mutual impedance analysis
D	Calculus differentiation with respect to physical properties

45. - E9C10

Which of the following describes a Zepp antenna?

Select	Answer
A	An omni-directional antenna commonly used for satellite communications
B	An end-fed dipole antenna
C	A dipole constructed from zip cord
D	A vertical array capable of quickly changing the direction of maximum radiation by changing phasing lines

46. - E9D05

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

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

47. - 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 gamma matching system
C	The stub matching system
D	The delta matching system

48. - E9F01

What is the velocity factor of a transmission line?

Select	Answer
A	The index of shielding for coaxial cable
B	The velocity of the wave in the transmission line multiplied by the velocity of light in a vacuum
C	The ratio of the characteristic impedance of the line to the terminating impedance
D	The velocity of the wave in the transmission line divided by the velocity of light in a vacuum

49. - E9G04

What are the two families of circles and arcs that make up a Smith chart?

Select	Answer
A	Reactance and voltage
B	Resistance and voltage
C	Voltage and impedance
D	Resistance and reactance

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

Figure E7-2

Figure E7-3