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, 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

2. - E1B06

Which of the following additional rules apply if you are installing an amateur station antenna at a site at or near a public use airport?

Select	Answer
A	No special rules apply if your antenna structure will be less than 300 feet in height
B	You may have to notify the Federal Aviation Administration and register it with the FCC as required by Part 17 of FCC rules
C	You must file an Environmental Impact Statement with the EPA before construction begins
D	You must obtain a construction permit from the airport zoning authority

3. - 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	CEPT agreement
D	All of these choices are correct

4. - E1D05

What class of licensee is authorized to be the control operator of a space station?

Select	Answer
A	Only Amateur Extra Class
B	Any class with appropriate operator privileges
C	All except Technician Class
D	Only General, Advanced or Amateur Extra Class

5. - E1E01

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

Select	Answer
A	5
B	3
C	2
D	4

6. - E1F11

Which of the following best describes one of the standards that must be met by an external RF power amplifier if it is to qualify for a grant of FCC certification?

Select	Answer
A	It must satisfy the FCC's spurious emission standards when operated at the lesser of 1500 watts or its full output power
B	It must be capable of external RF switching between its input and output networks
C	It must exhibit a gain of 0 dB or less over its full output range
D	It must produce full legal output when driven by not more than 5 watts of mean RF input power

7. - E2A09

What do the terms L band and S band specify with regard to satellite communications?

Select	Answer
A	Which sideband to use
B	The 23 centimeter and 13 centimeter bands
C	The 2 meter and 70 centimeter bands
D	FM and Digital Store-and-Forward systems

8. - E2B08

Which of the following is a common method of transmitting accompanying audio with amateur fast-scan television?

Select	Answer
A	Frequency modulation of the video carrier
B	Frequency-modulated sub-carrier
C	A separate VHF or UHF audio link
D	All of these choices are correct

9. - E2C08

Which of the following contacts may be confirmed through the U.S. QSL bureau system?

Select	Answer
A	Contacts using tactical call signs
B	Special event contacts between stations in the U.S.
C	Contacts between a U.S. station and a non-U.S. station
D	Repeater contacts between U.S. club members

10. - E2D12

How does JT65 improve EME communications?

Select	Answer
A	It can decode signals many dB below the noise floor using FEC
B	All of these choices are correct
C	It supplies signals to guide the antenna to track the Moon
D	It controls the receiver to track Doppler shift

11. - E2E06

What is the most common data rate used for HF packet?

Select	Answer
A	1200 baud
B	110 baud
C	300 baud
D	48 baud

12. - E3A16

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

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

13. - E3B12

What is the primary characteristic of chordal hop propagation?

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

14. - E3C01

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

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

15. - E4A05

What might be an advantage of a digital vs an analog oscilloscope?

Select	Answer
A	Automatic amplitude and frequency numerical readout
B	Manipulation of time base after trace capture
C	All of these choices are correct
D	Storage of traces for future reference

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

17. - E4C10

Which of the following is a desirable amount of selectivity for an amateur RTTY HF receiver?

Select	Answer
A	300 Hz
B	6000 Hz
C	2400 Hz
D	100 Hz

18. - E4D14

Which of the following is a way to reduce the likelihood of receiver desensitization?

Select	Answer
A	Switch from fast AGC to slow AGC
B	Raise the receiver IF frequency
C	Increase the receiver front end gain
D	Decrease the RF bandwidth of the receiver

19. - E4E10

What is a common characteristic of interference caused by a touch controlled electrical device?

Select	Answer
A	The interfering signal may drift slowly across the HF spectrum
B	The interfering signal can be several kHz in width and usually repeats at regular intervals across a HF band
C	All of these choices are correct
D	The interfering signal sounds like AC hum on an AM receiver or a carrier modulated by 60 Hz hum on a SSB or CW receiver

20. - E5A15

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

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

21. - 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?

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

22. - E5C09

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

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

23. - E5D05

Which parasitic characteristic increases with conductor length?

Select	Answer
A	Permittivity
B	Malleability
C	Permeability
D	Inductance

24. - E6A07

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

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

25. - E6B11

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

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

26. - E6C12

What is BiCMOS logic?

Select	Answer
A	A logic device with two CMOS circuits per package
B	A FET logic family based on bimetallic semiconductors
C	A logic family based on bismuth CMOS devices
D	An integrated circuit logic family using both bipolar and CMOS transistors

27. - E6D13

What is the primary cause of inductor self-resonance?

Select	Answer
A	The skin effect
B	Inter-turn capacitance
C	Inductive kickback
D	Non-linear core hysteresis

28. - E6E03

Which of the following materials is likely to provide the highest frequency of operation when used in MMICs?

Select	Answer
A	Silicon nitride
B	Silicon
C	Silicon dioxide
D	Gallium nitride

29. - E6F06

Which of these materials is affected the most by photoconductivity?

Select	Answer
A	A crystalline semiconductor
B	An ordinary metal
C	A liquid semiconductor
D	A heavy metal

30. - E7A02

What is the function of a decade counter digital IC?

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

31. - E7B13

In Figure E7-2, what is the purpose of R?

Select	Answer
A	Fixed bias
B	Emitter load
C	Collector load
D	Voltage regulation

32. - E7C01

How are the capacitors and inductors of a low-pass filter Pi-network arranged between the network's input and output?

Select	Answer
A	Two capacitors are in series between the input and output, and an inductor is connected between the two capacitors and ground
B	Two inductors are in series between the input and output, and a capacitor is connected between the two inductors and ground
C	A capacitor is connected between the input and ground, another capacitor is connected between the output and ground, and an inductor is connected between input and output
D	An inductor is connected between the input and ground, another inductor is connected between the output and ground, and a capacitor is connected between the input and output

33. - E7D06

What is the purpose of Q1 in the circuit shown in Figure E7-3?

Select	Answer
A	It increases the current-handling capability of the regulator
B	It provides D1 with current
C	It provides a constant load for the voltage source
D	It provides negative feedback to improve regulation

34. - E7E02

What is the function of a reactance modulator?

Select	Answer
A	To produce PM signals by using an electrically variable resistance
B	To produce PM signals by using an electrically variable inductance or capacitance
C	To produce AM signals by using an electrically variable inductance or capacitance
D	To produce AM signals by using an electrically variable resistance

35. - E7F06

What is the minimum number of bits required for an analog-to-digital converter to sample a signal with a range of 1 volt at a resolution of 1 millivolt?

Select	Answer
A	4 bits
B	6 bits
C	10 bits
D	8 bits

36. - E7G04

What is meant by the term op-amp input offset voltage?

Select	Answer
A	The potential between the amplifier input terminals of the op-amp in an open loop condition
B	The differential input voltage needed to bring the open loop output voltage to zero
C	The output voltage of the op-amp minus its input voltage
D	The difference between the output voltage of the op-amp and the input voltage required in the immediately following stage

37. - E7H10

What information is contained in the lookup table of a direct digital frequency synthesizer?

Select	Answer
A	The synthesizer frequency limits and frequency values stored in the radio memories
B	The phase relationship between a reference oscillator and the output waveform
C	The phase relationship between a voltage-controlled oscillator and the output waveform
D	The amplitude values that represent a sine-wave output

38. - E8A09

How many levels can an analog-to-digital converter with 8 bit resolution encode?

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

39. - E8B10

What describes frequency division multiplexing?

Select	Answer
A	Two or more information streams are merged into a baseband, which then modulates the transmitter
B	The transmitted signal is divided into packets of information
C	Two or more information streams are merged into a digital combiner, which then pulse position modulates the transmitter
D	The transmitted signal jumps from band to band at a predetermined rate

40. - E8C10

What is an advantage of Gray code in digital communications where symbols are transmitted as multiple bits

Select	Answer
A	It facilitates error detection
B	It has more resolution than simple binary
C	It has more possible states than simple binary
D	It increases security

41. - E8D01

Why are received spread spectrum signals resistant to interference?

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

42. - E9A03

Why would one need to know the feed point impedance of an antenna?

Select	Answer
A	To calculate the front-to-side ratio of the antenna
B	To match impedances in order to minimize standing wave ratio on the transmission line
C	To calculate the front-to-back ratio of the antenna
D	To measure the near-field radiation density from a transmitting antenna

43. - E9B12

What is the far field of an antenna?

Select	Answer
A	The region where the shape of the antenna pattern is independent of distance
B	The region where radiated field strengths are obstructed by objects of reflection
C	The region of the ionosphere where radiated power is not refracted
D	The region where radiated power dissipates over a specified time period

44. - E9C03

What is the radiation pattern of two 1/4 wavelength vertical antennas spaced a 1/2 wavelength apart and fed in phase?

Select	Answer
A	Omni-directional
B	A Figure-8 broadside to the axis of the array
C	A Figure-8 end-fire along the axis of the array
D	Cardioid

45. - E9D13

What usually occurs if a Yagi antenna is designed solely for maximum forward gain?

Select	Answer
A	The frequency response is widened over the whole frequency band
B	The front-to-back ratio increases
C	The front-to-back ratio decreases
D	The SWR is reduced

46. - E9E03

What is the name of the matching system that uses a section of transmission line connected in parallel with the feed line at or near the feed point?

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

47. - E9F16

Which of the following is a significant difference between foam dielectric coaxial cable and solid dielectric cable, assuming all other parameters are the same?

Select	Answer
A	All of these choices are correct
B	Foam dielectric has lower loss per unit of length
C	Foam dielectric has lower safe operating voltage limits
D	Foam dielectric has higher velocity factor

48. - E9G10

What do the arcs on a Smith chart represent?

Select	Answer
A	Points with constant resistance
B	SWR
C	Frequency
D	Points with constant reactance

49. - E9H11

What characteristic of a cardioid pattern antenna is useful for direction finding?

Select	Answer
A	Broad band response
B	A very sharp single null
C	A very sharp peak
D	High-radiation angle

50. - E0A07

How may dangerous levels of carbon monoxide from an emergency generator be detected?

Select	Answer
A	Any ordinary smoke detector can be used
B	Only with a carbon monoxide detector
C	By the odor
D	By the yellowish appearance of the gas

Figure E7-2

Figure E7-3