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

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

2. - E1B04

What must be done before placing an amateur station within an officially designated wilderness area or wildlife preserve, or an area listed in the National Register of Historical Places?

Select	Answer
A	A proposal must be submitted to the National Park Service
B	An Environmental Assessment must be submitted to the FCC
C	A letter of intent must be filed with the National Audubon Society
D	A form FSD-15 must be submitted to the Department of the Interior

3. - E1C06

Which of the following statements concerning remotely controlled amateur stations is true?

Select	Answer
A	Repeater and auxiliary stations may not be remotely controlled
B	Only Extra Class operators may be the control operator of a remote station
C	A control operator need not be present at the control point
D	A control operator must be present at the control point

4. - E1D07

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

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

5. - E1E04

Which of the following best describes the Volunteer Examiner accreditation process?

Select	Answer
A	Each General, Advanced and Amateur Extra Class operator is automatically accredited as a VE when the license is granted
B	The amateur operator applying must pass a VE examination administered by the FCC Enforcement Bureau
C	The procedure by which a VEC confirms that the VE applicant meets FCC requirements to serve as an examiner
D	The prospective VE obtains accreditation from the FCC

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

7. - E2A03

What is the orbital period of an Earth satellite?

Select	Answer
A	The point of maximum height of a satellite's orbit
B	The time it takes for a satellite to travel from perigee to apogee
C	The time it takes for a satellite to complete one revolution around the Earth
D	The point of minimum height of a satellite's orbit

8. - 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 identify the SSTV mode being used
C	To identify the call sign of the station transmitting
D	To provide vertical synchronization

9. - E2C03

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

Select	Answer
A	33 cm
B	30 m
C	6 m
D	2 m

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

11. - E2E09

Which of the following HF digital modes uses variable-length coding for bandwidth efficiency?

Select	Answer
A	MT63
B	PSK31
C	PACTOR
D	RTTY

12. - E3A16

Which of the following best describes electromagnetic waves traveling in free space?

Select	Answer
A	The energy propagates through a medium with a high refractive index
B	Electric and magnetic fields become aligned as they travel
C	The waves are reflected by the ionosphere and return to their source
D	Changing electric and magnetic fields propagate the energy

13. - E3B06

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

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

14. - E3C01

What does the term ray tracing describe in regard to radio communications?

Select	Answer
A	Evaluating high voltage sources for X-Rays
B	Modeling a radio wave's path through the ionosphere
C	Determining the radiation pattern from an array of antennas
D	The process in which an electronic display presents a pattern

15. - E4A11

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

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

16. - E4B10

Which of the following describes a method to measure intermodulation distortion in an SSB transmitter?

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

17. - E4C04

How is the noise figure of a receiver defined?

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

18. - E4D11

Why are third-order intermodulation products created within a receiver of particular interest compared to other products?

Select	Answer
A	The third-order intercept is much higher than other orders
B	The third-order product of two signals which are in the band of interest is also likely to be within the band
C	Third-order products are an indication of poor image rejection
D	Third-order intermodulation produces three products for every input signal within the band of interest

19. - E4E01

Which of the following types of receiver noise can often be reduced by use of a receiver noise blanker?

Select	Answer
A	Ignition noise
B	Heterodyne interference
C	Broadband white noise
D	All of these choices are correct

20. - E5A15

Which of the following can increase Q for inductors and capacitors?

Select	Answer
A	Lower losses
B	Lower reactance
C	Lower self-resonant frequency
D	Higher self-resonant frequency

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	110 seconds
C	440 seconds
D	55 seconds

22. - E5C09

When using rectangular coordinates to graph the impedance of a circuit, what does the horizontal axis represent?

Select	Answer
A	The difference between the resistive and reactive components
B	Reactive component
C	Resistive component
D	The sum of the reactive and resistive components

23. - E5D15

What is the power factor of an R-L circuit having a 45 degree phase angle between the voltage and the current?

Select	Answer
A	0.5
B	0.707
C	0.866
D	1.0

24. - E6A01

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

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

25. - E6B10

In Figure E6-3, what is the schematic symbol for a light-emitting diode?

Select	Answer
A	1
B	5
C	7
D	6

26. - E6C03

What is tri-state logic?

Select	Answer
A	Proprietary logic devices manufactured by Tri-State Devices
B	Logic devices that utilize ternary math
C	Low power logic devices designed to operate at 3 volts
D	Logic devices with 0, 1, and high impedance output states

27. - E6D08

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

Select	Answer
A	Powdered-iron cores generally require fewer turns to produce a given inductance
B	Powdered-iron cores use smaller diameter wire for the same inductance
C	Powdered-iron cores generally maintain their characteristics at higher currents
D	Powdered-iron cores generally have greater initial permeability

28. - E6E10

What is the packaging technique in which leadless components are soldered directly to circuit boards?

Select	Answer
A	Stripped lead
B	Direct soldering
C	Virtual lead mounting
D	Surface mount

29. - E6F10

What is the most common type of photovoltaic cell used for electrical power generation?

Select	Answer
A	Copper oxide
B	Selenium
C	Cadmium Sulfide
D	Silicon

30. - E7A09

What logical operation is performed by an exclusive NOR gate?

Select	Answer
A	It produces logic "0" at its output if any single input is logic "1"
B	It produces logic "1" at its output if any single input is logic "1"
C	It produces logic "1" at its output only if all inputs are logic "1"
D	It produces logic "0" at its output only if all inputs are logic "0"

31. - E7B10

In Figure E7-1, what is the purpose of R1 and R2?

Select	Answer
A	Load resistors
B	Fixed bias
C	Feedback
D	Self bias

32. - E7C12

Which describes a Pi-L-network used for matching a vacuum tube final amplifier to a 50 ohm unbalanced output?

Select	Answer
A	A network with only three discrete parts
B	A Phase Inverter Load network
C	A Pi-network with an additional series inductor on the output
D	A matching network in which all components are isolated from ground

33. - E7D12

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

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

34. - 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	1.414 and 0.707 times the input frequency
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	Change the gain by a factor of 3/4
B	Interpolate by a factor of three, then decimate by a factor of four
C	Add 3 to each input value and subtract 4 from each output value
D	Multiply each sample value by a factor of 3/4

36. - E7G08

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

Select	Answer
A	It decreases logarithmically with increasing frequency
B	It decreases linearly with increasing frequency
C	It does not vary with frequency
D	It increases linearly with increasing frequency

37. - E7H05

How is positive feedback supplied in a Pierce oscillator?

Select	Answer
A	Through a tapped coil
B	Through a neutralizing capacitor
C	Through link coupling
D	Through a quartz crystal

38. - E8A04

What is "dither" with respect to analog to digital converters?

Select	Answer
A	An abnormal condition where the converter cannot settle on a value to represent the signal
B	A small amount of noise added to the input signal to allow more precise representation of a signal over time
C	A method of decimation by randomly skipping samples
D	An error caused by irregular quantization step size

39. - 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	0.47
B	2.14
C	47
D	0.214

40. - E8C11

What is the relationship between symbol rate and baud?

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

41. - E8D03

How does the spread spectrum technique of frequency hopping work?

Select	Answer
A	A pseudo-random binary bit stream is used to shift the phase of an RF carrier very rapidly in a particular sequence
B	If interference is detected by the receiver it will signal the transmitter to change frequencies
C	The frequency of the transmitted signal is changed very rapidly according to a particular sequence also used by the receiving station
D	If interference is detected by the receiver it will signal the transmitter to wait until the frequency is clear

42. - E9A02

What antenna has no gain in any direction?

Select	Answer
A	Yagi
B	Isotropic antenna
C	Half-wave dipole
D	Quarter-wave vertical

43. - E9B01

In the antenna radiation pattern shown in Figure E9-1, what is the 3 dB beam-width?

Select	Answer
A	25 degrees
B	50 degrees
C	75 degrees
D	30 degrees

44. - E9C10

Which of the following describes a Zepp antenna?

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

45. - E9D10

What happens to feed point impedance at the base of a fixed length HF mobile antenna as the frequency of operation is lowered?

Select	Answer
A	The radiation resistance decreases and the capacitive reactance decreases
B	The radiation resistance increases and the capacitive reactance decreases
C	The radiation resistance decreases and the capacitive reactance increases
D	The radiation resistance increases and the capacitive reactance increases

46. - E9E07

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

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

47. - E9F11

What impedance does a 1/8 wavelength transmission line present to a generator when the line is open at the far end?

Select	Answer
A	An inductive reactance
B	The same as the characteristic impedance of the line
C	The same as the input impedance of the final generator stage
D	A capacitive reactance

48. - E9G03

Which of the following is often determined using a Smith chart?

Select	Answer
A	Satellite azimuth and elevation bearings
B	Beam headings and radiation patterns
C	Impedance and SWR values in transmission lines
D	Trigonometric functions

49. - E9H07

Why is it advisable to use an RF attenuator on a receiver being used for direction finding?

Select	Answer
A	It narrows the bandwidth of the received signal to improve signal to noise ratio
B	It compensates for the effects of an isotropic antenna, thereby improving directivity
C	It prevents receiver overload which could make it difficult to determine peaks or nulls
D	It reduces loss of received signals caused by antenna pattern nulls, thereby increasing sensitivity

50. - E0A08

What does SAR measure?

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

Figure E6-3

Figure E7-1

Figure E9-1