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

Logging in (or registering) will help the system to select questions that you need to focus on.

1. - E0A01

What is the primary function of an external earth connection or ground rod?

Select	Answer
A	Lightning protection
B	Reduce RF current flow between pieces of equipment
C	Reduce RFI to telephones and home entertainment systems
D	Reduce received noise

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 displayed frequency is within the 75 meter phone band segment
D	Yes, because the DX station initiated the contact

3. - E1B11

What does PRB-1 require of regulations affecting amateur radio?

Select	Answer
A	Reasonable accommodations of amateur radio must be made
B	No limitations may be placed on antenna size or placement
C	Use of wireless devices in a vehicle is exempt from regulation
D	Amateur radio operations must be permitted in any private residence

4. - E1C11

Which of the following operating arrangements allows an FCC-licensed U.S. citizen to operate in many European countries, and alien amateurs from many European countries to operate in the U.S.?

Select	Answer
A	ITU reciprocal license
B	IARP agreement
C	All these choices are correct
D	CEPT agreement

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. - E1E02

Who does Part 97 task with maintaining the pools of questions for all U.S. amateur license examinations?

Select	Answer
A	The ARRL
B	The FCC
C	The VECs
D	The VEs

7. - E1F06

Under what circumstances might the FCC issue a Special Temporary Authority (STA) to an amateur station?

Select	Answer
A	To allow regular operation on Land Mobile channels
B	To provide for experimental amateur communications
C	To provide temporary operation while awaiting normal licensing
D	To provide additional spectrum for personal use

8. - E2A11

What type of antenna can be used to minimize the effects of spin modulation and Faraday rotation?

Select	Answer
A	A circularly polarized antenna
B	An isotropic antenna
C	A log-periodic dipole array
D	A linearly polarized antenna

9. - E2B06

What is vestigial sideband modulation?

Select	Answer
A	Amplitude modulation in which one complete sideband and a portion of the other are transmitted
B	Narrow-band FM modulation achieved by filtering one sideband from the audio before frequency modulating the carrier
C	A type of modulation in which one sideband is inverted
D	Spread spectrum modulation achieved by applying FM modulation following single sideband amplitude modulation

10. - E2C12

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

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

11. - E2D06

Which of the following describes a method of establishing EME contacts?

Select	Answer
A	High-speed CW identification to avoid fading
B	Time synchronous transmissions alternately from each station
C	Storing and forwarding digital messages
D	Judging optimum transmission times by monitoring beacons reflected from the moon

12. - E2E13

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

Select	Answer
A	AMTOR
B	300 baud packet
C	170 Hz shift, 45 baud RTTY
D	PSK31

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	Forests
D	Mountain ranges

14. - E3B12

What is the primary characteristic of chordal hop propagation?

Select	Answer
A	Successive ionospheric refractions without an intermediate reflection from the ground
B	Propagation across the geomagnetic equator
C	Propagation away from the great circle bearing between stations
D	Signals reflected back toward the transmitting station

15. - E3C03

Which of the following signal paths is most likely to experience high levels of absorption when the A index or K index is elevated?

Select	Answer
A	Transequatorial
B	NVIS
C	Sporadic E
D	Polar

16. - E4A11

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

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

17. - E4B10

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

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

18. - E4C04

What is the noise figure of a receiver?

Select	Answer
A	The ratio of the noise bandwidth in hertz to the theoretical bandwidth of a resistive network
B	The ratio in dB of the noise generated by the receiver to the theoretical minimum noise
C	The ratio of atmospheric noise to phase 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 difference in dB between the noise floor and the level of an incoming signal that will cause 1 dB of gain compression
B	The difference in dB between the noise floor and the third-order intercept point
C	The minimum difference in dB between two signals which produce third-order intermodulation products greater than the noise floor
D	The minimum difference in dB between the levels of two FM signals that will cause one signal to block the other

20. - E4E04

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

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

21. - E5A02

What is resonance in an LC or RLC circuit?

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

22. - E5B01

What is the term for the time required for the capacitor in an RC circuit to be charged to 63.2% of the applied voltage or to discharge to 36.8% of its initial voltage?

Select	Answer
A	One exponential period
B	An exponential rate of one
C	One time constant
D	A time factor of one

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. - 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	0.5
D	1.73

25. - E6A02

Which of the following semiconductor materials contains excess free electrons?

Select	Answer
A	N-type
B	Insulated gate
C	P-type
D	Bipolar

26. - E6B03

What type of bias is required for an LED to emit light?

Select	Answer
A	Reverse bias
B	Zero bias
C	Inductive bias
D	Forward bias

27. - E6C02

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

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

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	Direct current
C	Excitation current
D	Magnetizing current

29. - E6E04

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

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

30. - E6F11

What is the approximate open-circuit voltage produced by a fully illuminated silicon photovoltaic cell?

Select	Answer
A	0.1 V
B	1.5 V
C	0.5 V
D	12 V

31. - E7A03

Which of the following can divide the frequency of a pulse train by 2?

Select	Answer
A	An OR gate
B	A multiplexer
C	A flip-flop
D	An XOR gate

32. - E7B04

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

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

33. - E7C06

What are the distinguishing features of an elliptical filter?

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

34. - E7D05

Which of the following types of linear voltage regulator places a constant load on the unregulated voltage source?

Select	Answer
A	A series regulator
B	A shunt current source
C	A shunt regulator
D	A constant current source

35. - E7E08

What are the principal frequencies that appear at the output of a mixer circuit?

Select	Answer
A	The two input frequencies along with their sum and difference frequencies
B	Two and four times the original frequency
C	The square root of the product of input frequencies
D	1.414 and 0.707 times the input frequency

36. - E7F10

What aspect of receiver analog-to-digital conversion determines the maximum receive bandwidth of a Direct Digital Conversion SDR?

Select	Answer
A	Sample clock phase noise
B	Sample rate
C	Processor latency
D	Sample width in bits

37. - E7G01

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

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

38. - E7H06

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

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

39. - E8A09

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

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

40. - E8B06

What is the deviation ratio of an FM-phone signal having a maximum frequency swing of plus or minus 7.5 kHz when the maximum modulation frequency is 3.5 kHz?

Select	Answer
A	0.214
B	2.14
C	47
D	0.47

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. - E8D11

What is one advantage of using ASCII code for data communications?

Select	Answer
A	It is possible to transmit both upper and lower case text
B	It uses one character as a shift code to send numeric and special characters
C	It includes built-in error correction features
D	It contains fewer information bits per character than any other code

43. - E9A01

What is an isotropic antenna?

Select	Answer
A	A grounded antenna used to measure Earth conductivity
B	A theoretical, omnidirectional antenna used as a reference for antenna gain
C	A horizontally polarized antenna used to compare Yagi antennas
D	A spacecraft antenna used to direct signals toward Earth

44. - E9B05

What type of antenna pattern is shown in Figure E9-2?

Select	Answer
A	Azimuth
B	Polarization
C	Elevation
D	Radiation resistance

45. - E9C11

How is the far-field elevation pattern of a vertically polarized antenna affected by being mounted over seawater versus soil?

Select	Answer
A	Fewer vertical angle lobes will be present
B	Additional higher vertical angle lobes will appear
C	The low-angle radiation decreases
D	The low-angle radiation increases

46. - E9D06

What happens to the SWR bandwidth when one or more loading coils are used to resonate an electrically short antenna?

Select	Answer
A	It is unchanged if the loading coil is located at the feed point
B	It is increased
C	It is decreased
D	It is unchanged if the loading coil is located at a voltage maximum point

47. - E9E06

Which of these feed line impedances would be suitable for constructing a quarter-wave Q-section for matching a 100-ohm loop to 50-ohm feed line?

Select	Answer
A	62 ohms
B	450 ohms
C	50 ohms
D	75 ohms

48. - E9F12

What impedance does a 1/4-wavelength transmission line present to a generator when the line is open at the far end?

Select	Answer
A	The same as the input impedance to the generator
B	Very high impedance
C	Very low impedance
D	The same as the characteristic impedance of the line

49. - E9G05

Which of the following is a common use for a Smith chart?

Select	Answer
A	Determine the impedance of a transmission line, given the physical dimensions
B	Determine the length and position of an impedance matching stub
C	Determine the gain of an antenna given the physical and electrical parameters
D	Determine the loss/100 feet of a transmission line, given the velocity factor and conductor materials

50. - E9H11

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

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

Figure E9-2