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

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1. - E1A14

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

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

2. - E1B07

What is the highest modulation index permitted at the highest modulation frequency for angle modulation below 29.0 MHz?

Select	Answer
A	3.0
B	2.0
C	0.5
D	1.0

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	The use of a control link between a control point and a locally controlled station
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	A station operating with its output power controlled automatically

4. - E1D01

What is the definition of the term telemetry?

Select	Answer
A	One-way transmission of measurements at a distance from the measuring instrument
B	Two-way radiotelephone transmissions in excess of 1000 feet
C	One-way transmission that initiates, modifies, or terminates the functions of a device at a distance
D	Two-way single channel transmissions of data

5. - E1E01

What is the minimum number of qualified VEs required to administer an Element 4 amateur operator license examination?

Select	Answer
A	4
B	2
C	3
D	5

6. - E1F07

When may an amateur station send a message to a business?

Select	Answer
A	When the control operator is employed by the FCC or another government agency
B	When neither the amateur nor his or her employer has a pecuniary interest in the communications
C	When the total money involved does not exceed $25
D	When transmitting international third-party communications

7. - E2A02

What is the direction of a descending pass for an amateur satellite?

Select	Answer
A	From north to south
B	From south to north
C	From east to west
D	From west to east

8. - E2B17

What is the approximate bandwidth of a slow-scan TV signal?

Select	Answer
A	3 kHz
B	600 Hz
C	2 MHz
D	6 MHz

9. - E2C10

Why might a DX station state that they are listening on another frequency?

Select	Answer
A	All of these choices are correct
B	Because the DX station may be transmitting on a frequency that is prohibited to some responding stations
C	To separate the calling stations from the DX station
D	To improve operating efficiency by reducing interference

10. - E2D02

Which of the following is a good technique for making meteor scatter contacts?

Select	Answer
A	15 second timed transmission sequences with stations alternating based on location
B	Short transmission with rapidly repeated call signs and signal reports
C	All of these choices are correct
D	Use of high speed CW or digital modes

11. - E2E11

What is the difference between direct FSK and audio FSK?

Select	Answer
A	Direct FSK uses a DC-coupled data connection
B	Audio FSK can be performed anywhere in the transmit chain
C	Audio FSK has a superior frequency response
D	Direct FSK applies the data signal to the transmitter VFO

12. - E3A06

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

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

13. - E3B11

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

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

14. - E3C01

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

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

15. - E4A04

What determines the upper frequency limit for a computer soundcard-based oscilloscope program?

Select	Answer
A	Q of the interface of the interface circuit
B	Analog-to-digital conversion speed of the soundcard
C	Amount of memory on the soundcard
D	All of these choices are correct

16. - E4B06

How much power is being absorbed by the load when a directional power meter connected between a transmitter and a terminating load reads 100 watts forward power and 25 watts reflected power?

Select	Answer
A	125 watts
B	100 watts
C	25 watts
D	75 watts

17. - E4C06

A CW receiver with the AGC off has an equivalent input noise power density of -174 dBm/Hz. What would be the level of an unmodulated carrier input to this receiver that would yield an audio output SNR of 0 dB in a 400 Hz noise bandwidth?

Select	Answer
A	-174 dBm
B	-148 dBm
C	-155 dBm
D	-164 dBm

18. - E4D04

Which of the following may reduce or eliminate intermodulation interference in a repeater caused by another transmitter operating in close proximity?

Select	Answer
A	A Class D final amplifier
B	A properly terminated circulator at the output of the transmitter
C	A band-pass filter in the feed line between the transmitter and receiver
D	A Class C final amplifier

19. - E4E16

What current flows equally on all conductors of an unshielded multi-conductor cable?

Select	Answer
A	Return current
B	Reactive current only
C	Common-mode current
D	Differential-mode current

20. - E5A04

What is the magnitude of the impedance of a circuit with a resistor, an inductor and a capacitor all in parallel, at resonance?

Select	Answer
A	Low, as compared to the circuit resistance
B	Approximately equal to circuit resistance
C	Approximately equal to capacitive reactance
D	Approximately equal to inductive reactance

21. - E5B13

What letter is commonly used to represent susceptance?

Select	Answer
A	X
B	G
C	Y
D	B

22. - E5C10

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

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

23. - E5D10

How can the true power be determined in an AC circuit where the voltage and current are out of phase?

Select	Answer
A	By dividing the apparent power by the power factor
B	By dividing the reactive power by the power factor
C	By multiplying the reactive power times the power factor
D	By multiplying the apparent power times the power factor

24. - E6A07

Which of the following indicates that a silicon NPN junction transistor is biased on?

Select	Answer
A	Base-to-emitter resistance of approximately 0.6 to 0.7 ohms
B	Base-to-emitter voltage of approximately 0.6 to 0.7 volts
C	Base-to-emitter resistance of approximately 6 to 7 ohms
D	Base-to-emitter voltage of approximately 6 to 7 volts

25. - E6B09

What is a common use for point contact diodes?

Select	Answer
A	As a high voltage rectifier
B	As a constant voltage source
C	As an RF detector
D	As a constant current source

26. - E6C06

Why do CMOS digital integrated circuits have high immunity to noise on the input signal or power supply?

Select	Answer
A	The input switching threshold is about two times the power supply voltage
B	Input signals are stronger
C	Larger bypass capacitors are used in CMOS circuit design
D	The input switching threshold is about one-half the power supply voltage

27. - E6D14

Which type of slug material decreases inductance when inserted into a coil?

Select	Answer
A	Ferrite
B	Powdered-iron
C	Ceramic
D	Brass

28. - E6E09

Which of the following component package types would be most suitable for use at frequencies above the HF range?

Select	Answer
A	Radial lead
B	Surface mount
C	TO-220
D	Axial lead

29. - E6F07

What is a solid state relay?

Select	Answer
A	A device that uses semiconductors to implement the functions of an electromechanical relay
B	A passive delay line
C	A relay using transistors to drive the relay coil
D	A mechanical relay that latches in the on or off state each time it is pulsed

30. - E7A02

What is the function of a decade counter digital IC?

Select	Answer
A	It produces ten output pulses for every input pulse
B	It adds two decimal numbers together
C	It decodes a decimal number for display on a seven segment LED display
D	It produces one output pulse for every ten input pulses

31. - E7B12

What type of amplifier circuit is shown in Figure E7-1?

Select	Answer
A	Emitter follower
B	Common emitter
C	Common base
D	Common collector

32. - E7C08

Which of the following factors has the greatest effect in helping determine the bandwidth and response shape of a crystal ladder filter?

Select	Answer
A	The relative frequencies of the individual crystals
B	The DC voltage applied to the quartz crystal
C	The gain of the RF stage preceding the filter
D	The amplitude of the signals passing through the filter

33. - E7D07

What is the purpose of C2 in the circuit shown in Figure E7-3?

Select	Answer
A	It bypasses hum around D1
B	It is a brute force filter for the output
C	To provide fixed DC bias for Q1
D	To self-resonate at the hum frequency

34. - E7E03

How does an analog phase modulator function?

Select	Answer
A	By varying the tuning of an amplifier tank circuit to produce AM signals
B	By varying the tuning of a microphone preamplifier to produce PM signals
C	By varying the tuning of a microphone preamplifier to produce AM signals
D	By varying the tuning of an amplifier tank circuit to produce PM signals

35. - E7F04

What is a common method of generating an SSB signal using digital signal processing?

Select	Answer
A	A frequency synthesizer removes the unwanted sidebands
B	Combine signals with a quadrature phase relationship
C	Mixing products are converted to voltages and subtracted by adder circuits
D	Emulation of quartz crystal filter characteristics

36. - E7G01

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

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

37. - E7H09

What type of frequency synthesizer circuit uses a phase accumulator, lookup table, digital to analog converter, and a low-pass anti-alias filter?

Select	Answer
A	A direct digital synthesizer
B	A phase locked loop synthesizer
C	A diode-switching matrix synthesizer
D	A hybrid synthesizer

38. - E8A08

Why would a direct or flash conversion analog-to-digital converter be useful for a software defined radio?

Select	Answer
A	Very high speed allows digitizing high frequencies
B	Immunity to out of sequence coding reduces spurious responses
C	All of these choices are correct
D	Very low power consumption decreases frequency drift

39. - E8B02

How does the modulation index of a phase-modulated emission vary with RF carrier frequency (the modulated frequency)?

Select	Answer
A	It does not depend on the RF carrier frequency
B	It decreases as the RF carrier frequency increases
C	It varies with the square root of the RF carrier frequency
D	It increases as the RF carrier frequency increases

40. - E8C04

What technique is used to minimize the bandwidth requirements of a PSK31 signal?

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

41. - E8D08

What parameter might indicate that excessively high input levels are causing distortion in an AFSK signal?

Select	Answer
A	Intermodulation Distortion (IMD)
B	Baud rate
C	Repeat Request Rate (RRR)
D	Signal to noise ratio

42. - E9A06

How does the beamwidth of an antenna vary as the gain is increased?

Select	Answer
A	It decreases
B	It increases geometrically
C	It increases arithmetically
D	It is essentially unaffected

43. - E9B07

How does the total amount of radiation emitted by a directional gain antenna compare with the total amount of radiation emitted from an isotropic antenna, assuming each is driven by the same amount of power?

Select	Answer
A	The total amount of radiation from the directional antenna is stronger by its front-to-back ratio
B	The total amount of radiation from the directional antenna is increased by the gain of the antenna
C	The radiation from the isotropic antenna is 2.15 dB stronger than that from the directional antenna
D	They are the same

44. - E9C11

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

Select	Answer
A	The low-angle radiation decreases
B	The high-angle radiation increases
C	Both the high-angle and low-angle radiation decrease
D	The low-angle radiation increases

45. - E9D05

What is a disadvantage of using a multiband trapped antenna?

Select	Answer
A	It is too sharply directional at lower frequencies
B	It must be neutralized
C	It radiates the harmonics and fundamental equally well
D	It might radiate harmonics

46. - E9E05

How must the driven element in a 3-element Yagi be tuned to use a hairpin matching system?

Select	Answer
A	The driven element reactance must be capacitive
B	The driven element reactance must be inductive
C	The driven element resonance must be lower than the operating frequency
D	The driven element radiation resistance must be higher than the characteristic impedance of the transmission line

47. - E9F09

What is the approximate physical length of a solid polyethylene dielectric coaxial transmission line that is electrically one-quarter wavelength long at 7.2 MHz?

Select	Answer
A	10 meters
B	50 meters
C	6.9 meters
D	24 meters

48. - E9G04

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

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

49. - E9H04

What is an advantage of using a shielded loop antenna for direction finding?

Select	Answer
A	It is electro statically balanced against ground, giving better nulls
B	It allows stations to communicate without giving away their position
C	It automatically cancels ignition noise in mobile installations
D	It eliminates tracking errors caused by strong out-of-band signals

50. - E0A02

When evaluating RF exposure levels from your station at a neighbor's home, what must you do?

Select	Answer
A	Make sure signals from your station are less than the uncontrolled MPE limits
B	Make sure signals from your station are less than the controlled MPE limits
C	Advise your neighbors of the results of your tests
D	You need only evaluate exposure levels on your own property

Figure E7-1

Figure E7-3