US Amateur Radio - Amateur Extra (Element 4, 2016-2020) Practice Test

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1. - E1A12

With your transceiver displaying the carrier frequency of CW signals, you hear a DX station's CQ on 3.500 MHz. Is it legal to return the call using CW on the same frequency?

Select	Answer
A	Yes, the DX station initiated the contact
B	No, one of the sidebands of the CW signal will be out of the band
C	Yes, the displayed frequency is within the 80 meter CW band segment
D	No, U.S. stations are not permitted to use CW emissions below 3.525 MHz

2. - E1B11

What is the permitted mean power of any spurious emission relative to the mean power of the fundamental emission from a station transmitter or external RF amplifier installed after January 1, 2003 and transmitting on a frequency below 30 MHZ?

Select	Answer
A	At least 73 dB below
B	At least 43 dB below
C	At least 53 dB below
D	At least 63 dB below

3. - E1C02

What is meant by automatic control of a station?

Select	Answer
A	Remotely controlling a station's antenna pattern through a directional control link
B	A station operating with its output power controlled automatically
C	The use of devices and procedures for control so that the control operator does not have to be present at a control point
D	The use of a control link between a control point and a locally controlled station

4. - E1D07

Which amateur service HF bands have frequencies authorized for space stations?

Select	Answer
A	Only the 40 m, 20 m, 17 m, 15 m and 10 m bands
B	Only the 40 m, 20 m, 17 m, 15 m, 12 m and 10 m bands
C	All HF bands
D	Only the 40 m, 30 m, 20 m, 15 m, 12 m and 10 m bands

5. - E1E12

What must the VE team do with the application form if the examinee does not pass the exam?

Select	Answer
A	Maintain the application form with the VEC's records
B	Destroy the application form
C	Return the application document to the examinee
D	Send the application form to the FCC and inform the FCC of the grade

6. - E1F02

What privileges are authorized in the U.S. to persons holding an amateur service license granted by the Government of Canada?

Select	Answer
A	Full privileges, up to and including those of the Extra Class License, on the 80, 40, 20, 15, and 10 meter bands
B	The operating terms and conditions of the Canadian amateur service license, not to exceed U.S. Extra Class privileges
C	None, they must obtain a U.S. license
D	All privileges of the Extra Class license

7. - E2A12

What is one way to predict the location of a satellite at a given time?

Select	Answer
A	By calculations using the Keplerian elements for the specified satellite
B	By adding the mean anomaly to the orbital inclination
C	By means of the Doppler data for the specified satellite
D	By subtracting the mean anomaly from the orbital inclination

8. - E2B02

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

Select	Answer
A	1080
B	60
C	30
D	525

9. - E2C12

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

10. - E2D05

Which of the following techniques is normally used by low Earth orbiting digital satellites to relay messages around the world?

Select	Answer
A	Multi-satellite relaying
B	Store-and-forward
C	Node hopping
D	Digipeating

11. - E2E08

Which of the following HF digital modes can be used to transfer binary files?

Select	Answer
A	RTTY
B	AMTOR
C	Hellschreiber
D	PACTOR

12. - E3A06

Which of the following is required for microwave propagation via rain scatter?

Select	Answer
A	Rain droplets must be electrically charged
B	The rain must be within radio range of both stations
C	Rain droplets must be within the E layer
D	All of these choices are correct

13. - E3B11

At what time of day is Sporadic-E propagation most likely to occur?

Select	Answer
A	Around sunrise
B	Around sunset
C	Early evening
D	Any time

14. - E3C02

What is indicated by a rising A or K index?

Select	Answer
A	Increasing disruption of the geomagnetic field
B	Higher levels of solar UV radiation
C	Decreasing disruption of the geomagnetic field
D	An increase in the critical frequency

15. - E4A11

Which of the following is good practice when using an oscilloscope probe?

Select	Answer
A	Never use a high impedance probe to measure a low impedance circuit
B	Keep the signal ground connection of the probe as short as possible
C	Never use a DC-coupled probe to measure an AC circuit
D	All of these choices are correct

16. - E4B01

Which of the following factors most affects the accuracy of a frequency counter?

Select	Answer
A	Decade divider accuracy
B	Time base accuracy
C	Input attenuator accuracy
D	Temperature coefficient of the logic

17. - E4C11

Which of the following is a desirable amount of selectivity for an amateur SSB phone receiver?

Select	Answer
A	2.4 kHz
B	4.2 kHz
C	1 kHz
D	4.8 kHz

18. - E4D09

What is the purpose of the preselector in a communications receiver?

Select	Answer
A	To allow selection of the optimum RF amplifier device
B	To increase rejection of unwanted signals
C	To store often-used frequencies
D	To provide a range of AGC time constants

19. - E4E11

Which is the most likely cause if you are hearing combinations of local AM broadcast signals within one or more of the MF or HF ham bands?

Select	Answer
A	Nearby corroded metal joints are mixing and re-radiating the broadcast signals
B	You are receiving sky wave signals from a distant station
C	Your station receiver IF amplifier stage is defective
D	The broadcast station is transmitting an over-modulated signal

20. - E5A01

What can cause the voltage across reactances in series to be larger than the voltage applied to them?

Select	Answer
A	Resonance
B	Capacitance
C	Conductance
D	Resistance

21. - 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	220 seconds
B	55 seconds
C	110 seconds
D	440 seconds

22. - E5C11

What do the two numbers that are used to define a point on a graph using rectangular coordinates represent?

Select	Answer
A	The sine and cosine values
B	The tangent and cotangent values
C	The coordinate values along the horizontal and vertical axes
D	The magnitude and phase of the point

23. - E5D18

How many watts are consumed in a circuit having a power factor of 0.71 if the apparent power is 500VA?

Select	Answer
A	1.42 mW
B	355 W
C	252 W
D	704 W

24. - E6A01

In what application is gallium arsenide used as a semiconductor material in preference to germanium or silicon?

Select	Answer
A	In high-current rectifier circuits
B	In microwave circuits
C	In very low frequency RF circuits
D	In high-power audio circuits

25. - E6B03

What special type of diode is capable of both amplification and oscillation?

Select	Answer
A	Tunnel
B	Point contact
C	Junction
D	Zener

26. - E6C07

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

Select	Answer
A	A resistor in a keying circuit used to reduce key clicks
B	A resistor connected to an op-amp output that only functions when the logic output is false
C	A resistor connected to the positive or negative supply line used to establish a voltage when an input or output is an open circuit
D	A resistor that insures that an oscillator frequency does not drive lower over time

27. - E6D01

How many turns will be required to produce a 5-microhenry inductor using a powdered-iron toroidal core that has an inductance index (A L) value of 40 microhenrys/100 turns?

Select	Answer
A	79 turns
B	141 turns
C	35 turns
D	13 turns

28. - E6E08

How is voltage from a power supply normally furnished to the most common type of monolithic microwave integrated circuit (MMIC)?

Select	Answer
A	Through a resistor and/or RF choke connected to the amplifier output lead
B	Directly to the bias voltage (VCC IN) lead
C	Through a capacitor and RF choke connected to the amplifier input lead
D	MMICs require no operating bias

29. - E6F09

What is the efficiency of a photovoltaic cell?

Select	Answer
A	The relative fraction of light that is converted to current
B	The open-circuit voltage divided by the short-circuit current under full illumination
C	The output RF power divided by the input DC power
D	The effective payback period

30. - E7A12

What type of logic defines "0" as a high voltage?

Select	Answer
A	Positive Logic
B	Reverse Logic
C	Negative logic
D	Assertive Logic

31. - E7B16

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

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

32. - E7C15

What is a crystal lattice filter?

Select	Answer
A	An audio filter made with four quartz crystals that resonate at 1kHz intervals
B	A power supply filter made with interlaced quartz crystals
C	A filter with wide bandwidth and shallow skirts made using quartz crystals
D	A filter with narrow bandwidth and steep skirts made using quartz crystals

33. - E7D12

What is the drop-out voltage of an analog voltage regulator?

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

34. - E7E08

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

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

35. - E7F16

How might the sampling rate of an existing digital signal be adjusted by a factor of 3/4?

Select	Answer
A	Multiply each sample value by a factor of 3/4
B	Change the gain by a factor of 3/4
C	Interpolate by a factor of three, then decimate by a factor of four
D	Add 3 to each input value and subtract 4 from each output value

36. - E7G07

What magnitude of voltage gain can be expected from the circuit in Figure E7-4 when R1 is 10 ohms and RF is 470 ohms?

Select	Answer
A	94
B	24
C	0.21
D	47

37. - E7H12

Which of the following must be done to insure that a crystal oscillator provides the frequency specified by the crystal manufacturer?

Select	Answer
A	Provide the crystal with a specified parallel inductance
B	Provide the crystal with a specified parallel capacitance
C	Bias the crystal at a specified current
D	Bias the crystal at a specified voltage

38. - E8A01

What is the name of the process that shows that a square wave is made up of a sine wave plus all of its odd harmonics?

Select	Answer
A	Fourier analysis
B	Differential analysis
C	Vector analysis
D	Numerical analysis

39. - E8B08

What describes Orthogonal Frequency Division Multiplexing?

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

40. - E8C01

How is Forward Error Correction implemented?

Select	Answer
A	By transmitting a special algorithm to the receiving station along with the data characters
B	By varying the frequency shift of the transmitted signal according to a predefined algorithm
C	By transmitting extra data that may be used to detect and correct transmission errors
D	By the receiving station repeating each block of three data characters

41. - E8D02

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

Select	Answer
A	Frequency hopping
B	Binary phase-shift keying
C	Direct sequence
D	Phase compandored spread spectrum

42. - E9A05

What is included in the total resistance of an antenna system?

Select	Answer
A	Transmission-line resistance plus radiation resistance
B	Radiation resistance plus ohmic resistance
C	Radiation resistance plus space impedance
D	Radiation resistance plus transmission resistance

43. - E9B06

What is the elevation angle of peak response in the antenna radiation pattern shown in Figure E9-2?

Select	Answer
A	7.5 degrees
B	25 degrees
C	45 degrees
D	75 degrees

44. - E9C08

What is a folded dipole antenna?

Select	Answer
A	A dipole configured to provide forward gain
B	A type of ground-plane antenna
C	A dipole one-quarter wavelength long
D	A dipole consisting of one wavelength of wire forming a very thin loop

45. - E9D12

Which of the following would provide the best RF ground for your station?

Select	Answer
A	An electrically short connection to 3 or 4 interconnected ground rods via a series RF choke
B	A 50 ohm resistor connected to ground
C	An electrically short connection to a metal water pipe
D	An electrically short connection to 3 or 4 interconnected ground rods driven into the Earth

46. - E9E07

What term best describes the interactions at the load end of a mismatched transmission line?

Select	Answer
A	Velocity factor
B	Dielectric constant
C	Characteristic impedance
D	Reflection coefficient

47. - E9F05

What is the approximate physical length of a solid polyethylene dielectric coaxial transmission line that is electrically one-quarter wavelength long at 14.1 MHz?

Select	Answer
A	20 meters
B	0.2 meters
C	2.3 meters
D	3.5 meters

48. - E9G04

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

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

49. - E9H05

What is the main drawback of a wire-loop antenna for direction finding?

Select	Answer
A	It is non-rotatable
B	It receives equally well in all directions
C	It is practical for use only on VHF bands
D	It has a bidirectional pattern

50. - E0A08

What does SAR measure?

Select	Answer
A	Synthetic Aperture Ratio of the human body
B	Signal Amplification Rating
C	The rate of RF energy reflected from stationary terrain
D	The rate at which RF energy is absorbed by the body

Figure E7-4

Figure E9-2