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	The body reacts to electromagnetic radiation from both the E and H fields
C	Ground reflections and scattering make the field strength vary with location
D	E field and H field radiation intensity peaks can occur at different locations

2. - E1A04

With your transceiver displaying the carrier frequency of phone signals, you hear a DX station calling CQ on 3.601 MHz LSB. Is it legal to return the call using lower sideband on the same frequency?

Select	Answer
A	No, U.S. stations are not permitted to use phone emissions below 3.610 MHz
B	No, the sideband will extend beyond the edge of the phone band segment
C	Yes, because the DX station initiated the contact
D	Yes, because the displayed frequency is within the 75 meter phone band segment

3. - E1B12

What must the control operator of a repeater operating in the 70 cm band do if a radiolocation system experiences interference from that repeater?

Select	Answer
A	File an FAA NOTAM (Notice to Airmen) with the repeater system's ERP, call sign, and six-character grid locator
B	Reduce the repeater antenna HAAT (Height Above Average Terrain)
C	Cease operation or make changes to the repeater to mitigate the interference
D	All these choices are correct

4. - E1C01

What is the maximum bandwidth for a data emission on 60 meters?

Select	Answer
A	60 Hz
B	1.5 kHz
C	170 Hz
D	2.8 kHz

5. - E1D02

Which of the following may transmit special codes intended to obscure the meaning of messages?

Select	Answer
A	Auxiliary relay links carrying repeater audio
B	Telecommand signals from a space telecommand station
C	Binary control characters
D	Data containing personal information

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

8. - E2A03

How is the signal inverted by an inverting linear transponder?

Select	Answer
A	The signal is passed through a non-linear filter
B	The signal is reduced to I and Q components and the Q component is filtered out
C	The signal is passed through a mixer and the difference rather than the sum is transmitted
D	The signal is detected and remodulated on the reverse sideband

9. - E2B11

What is the function of the Vertical Interval Signaling (VIS) code sent as part of an SSTV transmission?

Select	Answer
A	To lock the color burst oscillator in color SSTV images
B	To provide vertical synchronization
C	To identify the call sign of the station transmitting
D	To identify the SSTV mode being used

10. - E2C03

From which of the following bands is amateur radio contesting generally excluded?

Select	Answer
A	30 meters
B	33 centimeters
C	2 meters
D	6 meters

11. - E2D03

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

Select	Answer
A	MSK144
B	PACTOR III
C	JT65
D	Olivia

12. - E2E07

Which of the following is a possible reason that attempts to initiate contact with a digital station on a clear frequency are unsuccessful?

Select	Answer
A	All these choices are correct
B	The protocol version you are using is not supported by the digital station
C	Your transmit frequency is incorrect
D	Another station you are unable to hear is using the frequency

13. - E3A02

What characterizes libration fading of an EME signal?

Select	Answer
A	A gradual loss of signal as the sun rises
B	The returning echo is several hertz lower in frequency than the transmitted signal
C	A fluttery irregular fading
D	A slow change in the pitch of the CW signal

14. - E3B06

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

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

15. - E3C14

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

Select	Answer
A	D-region skip
B	Due to the Doppler effect
C	Downward bending due to density variations in the atmosphere
D	E-region skip

16. - E4A08

Which of the following measures SWR?

Select	Answer
A	A Q meter
B	An antenna analyzer
C	An ohmmeter
D	A spectrum analyzer

17. - E4B04

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

Select	Answer
A	S21
B	S22
C	S11
D	S12

18. - E4C13

How does a narrow-band roofing filter affect receiver performance?

Select	Answer
A	It improves dynamic range by attenuating strong signals near the receive frequency
B	It improves sensitivity by reducing front end noise
C	It improves intelligibility by using low Q circuitry to reduce ringing
D	All these choices are correct

19. - E4D01

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

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

20. - E4E01

What problem can occur when using an automatic notch filter (ANF) to remove interfering carriers while receiving CW signals?

Select	Answer
A	Any nearby signal passing through the DSP system will overwhelm the desired signal
B	Ringing in the DSP filter will completely remove the spaces between the CW characters
C	Removal of the CW signal as well as the interfering carrier
D	Received CW signals will appear to be modulated at the DSP clock frequency

21. - E5A02

What is resonance in an LC or RLC circuit?

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

22. - E5B08

What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 100 ohms, R is 100 ohms, and XL is 75 ohms?

Select	Answer
A	76 degrees with the voltage leading the current
B	14 degrees with the voltage lagging the current
C	14 degrees with the voltage leading the current
D	76 degrees with the voltage lagging the current

23. - E5C02

How are impedances described in polar coordinates?

Select	Answer
A	By real and imaginary parts
B	By X and R values
C	By Y and G values
D	By phase angle and magnitude

24. - E5D14

What is reactive power?

Select	Answer
A	Power lost because of capacitor leakage
B	Wattless, nonproductive power
C	Power consumed in wire resistance in an inductor
D	Power consumed in circuit Q

25. - E6A11

In Figure E6-1, what is the schematic symbol for a P-channel junction FET?

Select	Answer
A	2
B	1
C	3
D	6

26. - E6B11

What is used to control the attenuation of RF signals by a PIN diode?

Select	Answer
A	A sub-harmonic pump signal
B	Capacitance of an RF coupling capacitor
C	Reverse voltage larger than the RF signal
D	Forward DC bias current

27. - E6C02

What happens when the level of a comparator's input signal crosses the threshold?

Select	Answer
A	The feedback loop becomes unstable
B	The IC input can be damaged
C	The comparator enters latch-up
D	The comparator changes its output state

28. - E6D10

What is a primary advantage of using a toroidal core instead of a solenoidal core in an inductor?

Select	Answer
A	Toroidal cores make it easier to couple the magnetic energy into other components
B	Toroidal cores confine most of the magnetic field within the core material
C	Toroidal cores exhibit greater hysteresis
D	Toroidal cores have lower Q characteristics

29. - E6E05

Which of the following noise figure values is typical of a low-noise UHF preamplifier?

Select	Answer
A	-20 dBm
B	-10 dB
C	44 dBm
D	2 dB

30. - E6F05

Which describes an optical shaft encoder?

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

31. - E7A10

What is a truth table?

Select	Answer
A	A list of inputs and corresponding outputs for a digital device
B	A table of logic symbols that indicate the logic states of an op-amp
C	A table of logic symbols that indicate the high logic states of an op-amp
D	A diagram showing logic states when the digital device output is true

32. - E7B18

What is a characteristic of a grounded-grid amplifier?

Select	Answer
A	Low input impedance
B	Low bandwidth
C	High power gain
D	High filament voltage

33. - E7C03

What advantage does a series-L Pi-L-network have over a series-L Pi-network for impedance matching between the final amplifier of a vacuum-tube transmitter and an antenna?

Select	Answer
A	Higher efficiency
B	Greater harmonic suppression
C	Greater transformation range
D	Does not require a capacitor

34. - E7D12

What is the dropout voltage of an analog voltage regulator?

Select	Answer
A	Minimum input voltage for rated power dissipation
B	Minimum input-to-output voltage required to maintain regulation
C	Maximum that the output voltage may decrease at rated load
D	Maximum output voltage drops when the input voltage is varied over its specified range

35. - E7E07

What is meant by the term "baseband" in radio communications?

Select	Answer
A	The lowest frequency band that the transmitter or receiver covers
B	The basic oscillator frequency in an FM transmitter that is multiplied to increase the deviation and carrier frequency
C	The unmodulated bandwidth of the transmitted signal
D	The frequency range occupied by a message signal prior to modulation

36. - E7F02

What kind of digital signal processing audio filter is used to remove unwanted noise from a received SSB signal?

Select	Answer
A	A Hilbert-transform filter
B	A phase-inverting filter
C	An adaptive filter
D	A crystal-lattice filter

37. - E7G03

What is the typical input impedance of an op-amp?

Select	Answer
A	100 ohms
B	Very high
C	1000 ohms
D	Very low

38. - E7H06

Which of the following oscillator circuits are commonly used in VFOs?

Select	Answer
A	Colpitts and Hartley
B	Pierce and Zener
C	Negative feedback and balanced feedback
D	Armstrong and deForest

39. - E8A09

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

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

40. - E8B04

What is the modulation index of an FM-phone signal having a maximum carrier deviation of plus or minus 6 kHz when modulated with a 2 kHz modulating frequency?

Select	Answer
A	6000
B	2000
C	1/3
D	3

41. - E8C11

What is the relationship between symbol rate and baud?

Select	Answer
A	They are the same
B	Baud is only used for RTTY
C	Symbol rate is only used for packet-based modes
D	Baud is twice the symbol rate

42. - E8D01

Why are received spread spectrum signals resistant to interference?

Select	Answer
A	If interference is detected by the receiver it will signal the transmitter to change frequencies
B	Signals not using the spread spectrum algorithm are suppressed in the receiver
C	The high power used by a spread spectrum transmitter keeps its signal from being easily overpowered
D	The receiver is always equipped with a digital blanker

43. - E9A13

What term describes station output, taking into account all gains and losses?

Select	Answer
A	Apparent power
B	Half-power bandwidth
C	Power factor
D	Effective radiated power

44. - E9B04

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

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

45. - E9C04

What happens to the radiation pattern of an unterminated long wire antenna as the wire length is increased?

Select	Answer
A	The lobes become more perpendicular to the wire
B	The front-to-back ratio decreases
C	The vertical angle increases
D	The lobes align more in the direction of the wire

46. - E9D03

Where should a high Q loading coil be placed to minimize losses in a shortened vertical antenna?

Select	Answer
A	As close to the transmitter as possible
B	At a voltage node
C	Near the center of the vertical radiator
D	As low as possible on the vertical radiator

47. - E9E02

What is the name of an antenna matching system that matches an unbalanced feed line to an antenna by feeding the driven element both at the center of the element and at a fraction of a wavelength to one side of center?

Select	Answer
A	The delta match
B	The gamma match
C	The epsilon match
D	The stub match

48. - E9F03

Why is the physical length of a coaxial cable transmission line shorter than its electrical length?

Select	Answer
A	Electrical signals move more slowly in a coaxial cable than in air
B	The surge impedance is higher in a parallel feed line
C	The characteristic impedance is higher in a parallel feed line
D	Skin effect is less pronounced in the coaxial cable

49. - E9G11

How are the wavelength scales on a Smith chart calibrated?

Select	Answer
A	In fractions of antenna electrical frequency
B	In fractions of antenna electrical wavelength
C	In fractions of transmission line electrical frequency
D	In fractions of transmission line electrical wavelength

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

Figure E6-1