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

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

1. - E1A05

What is the maximum power output permitted on the 60 meter band?

Select	Answer
A	50 watts PEP effective radiated power relative to an isotropic radiator
B	50 watts PEP effective radiated power relative to a dipole
C	100 watts PEP effective radiated power relative to an isotropic radiator
D	100 watts PEP effective radiated power relative to the gain of a half-wave dipole

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

3. - E1C02

What is meant by automatic control of a station?

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

4. - E1D03

What is a telecommand station in the amateur satellite service?

Select	Answer
A	An amateur station that transmits communications to initiate, modify or terminate functions of a space station
B	An amateur station located on the Earth's surface for communication with other Earth stations by means of Earth satellites
C	An amateur station located more than 50 km above the Earth's surface
D	An amateur station that transmits telemetry consisting of measurements of upper atmosphere

5. - E1E05

What is the minimum passing score on amateur operator license examinations?

Select	Answer
A	Minimum passing score of 74%
B	Minimum passing score of 77%
C	Minimum passing score of 80%
D	Minimum passing score of 70%

6. - E1F01

On what frequencies are spread spectrum transmissions permitted?

Select	Answer
A	Only on amateur frequencies above 144 MHz
B	Only on amateur frequencies above 420 MHz
C	Only on amateur frequencies above 50 MHz
D	Only on amateur frequencies above 222 MHz

7. - E2A07

Which of the following types of signals can be relayed through a linear transponder?

Select	Answer
A	FM and CW
B	SSB and SSTV
C	PSK and Packet
D	All of these choices are correct

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	All of these choices are correct
D	A separate VHF or UHF audio link

9. - E2C06

During a VHF/UHF contest, in which band segment would you expect to find the highest level of activity?

Select	Answer
A	In the middle of each band, usually on the national calling frequency
B	In the weak signal segment of the band, with most of the activity near the calling frequency
C	In the middle of the band, usually 25 kHz above the national calling frequency
D	At the top of each band, usually in a segment reserved for contests

10. - E2D02

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

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

11. - E2E04

What is indicated when one of the ellipses in an FSK crossed-ellipse display suddenly disappears?

Select	Answer
A	The mark and space signal have been inverted
B	The receiver has drifted 5 kHz from the desired receive frequency
C	One of the signal filters is saturated
D	Selective fading has occurred

12. - E3A09

Which of the following frequency range is most suited for meteor scatter communications?

Select	Answer
A	10 MHz - 14 MHz
B	1.8 MHz - 1.9 MHz
C	28 MHz - 148 MHz
D	220 MHz - 450 MHz

13. - E3B01

What is transequatorial propagation?

Select	Answer
A	Propagation between two mid-latitude points at approximately the same distance north and south of the magnetic equator
B	Propagation between two stations at the same latitude
C	Propagation between two continents by way of ducts along the magnetic equator
D	Propagation between any two points located on the magnetic equator

14. - E3C08

What does the space weather term G5 mean?

Select	Answer
A	An extreme geomagnetic storm
B	Waning sunspot numbers
C	Very low solar activity
D	Moderate solar wind

15. - E4A05

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

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

16. - E4B12

What is the significance of voltmeter sensitivity expressed in ohms per volt?

Select	Answer
A	When used as a galvanometer, the reading in volts multiplied by the ohms per volt rating will determine the power drawn by the device under test
B	When used as an ammeter, the full scale reading in amps divided by ohms per volt rating will determine the size of shunt needed
C	When used as an ohmmeter, the reading in ohms divided by the ohms per volt rating will determine the voltage applied to the circuit
D	The full scale reading of the voltmeter multiplied by its ohms per volt rating will indicate the input impedance of the voltmeter

17. - E4C01

What is an effect of excessive phase noise in the local oscillator section of a receiver?

Select	Answer
A	It decreases receiver third-order intermodulation distortion dynamic range
B	It reduces receiver sensitivity
C	It can cause strong signals on nearby frequencies to interfere with reception of weak signals
D	It limits the receiver's ability to receive strong signals

18. - E4D06

What is the term for unwanted signals generated by the mixing of two or more signals?

Select	Answer
A	Intermodulation interference
B	Amplifier desensitization
C	Adjacent channel interference
D	Neutralization

19. - E4E12

What is one disadvantage of using some types of automatic DSP notch-filters when attempting to copy CW signals?

Select	Answer
A	Any nearby signal passing through the DSP system will overwhelm the desired signal
B	A DSP filter can remove the desired signal at the same time as it removes interfering signals
C	Received CW signals will appear to be modulated at the DSP clock frequency
D	Ringing in the DSP filter will completely remove the spaces between the CW characters

20. - E5A10

How is the Q of an RLC series resonant circuit calculated?

Select	Answer
A	Reactance of the inductance times the reactance of the capacitance
B	Reactance of either the inductance or capacitance times the resistance
C	Resistance divided by the reactance of either the inductance or capacitance
D	Reactance of either the inductance or capacitance divided by the resistance

21. - E5B09

What is the relationship between the current through a capacitor and the voltage across a capacitor?

Select	Answer
A	Voltage and current are in phase
B	Voltage and current are 180 degrees out of phase
C	Voltage leads current by 90 degrees
D	Current leads voltage by 90 degrees

22. - E5C08

What coordinate system is often used to display the phase angle of a circuit containing resistance, inductive and/or capacitive reactance?

Select	Answer
A	Maidenhead grid
B	Elliptical coordinates
C	Polar coordinates
D	Faraday grid

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

24. - E6A10

In Figure E6-2, what is the schematic symbol for an N-channel dual-gate MOSFET?

Select	Answer
A	2
B	4
C	5
D	6

25. - E6B06

Which of the following is a common use of a hot-carrier diode?

Select	Answer
A	As balanced mixers in FM generation
B	As a constant voltage reference in a power supply
C	As a VHF/UHF mixer or detector
D	As a variable capacitance in an automatic frequency control circuit

26. - E6C14

What is the primary advantage of using a Programmable Gate Array (PGA) in a logic circuit?

Select	Answer
A	All of these choices are correct
B	Many similar gates are less expensive than a mixture of gate types
C	A PGA contains its own internal power supply
D	Complex logic functions can be created in a single integrated circuit

27. - E6D17

Why should core saturation of a conventional impedance matching transformer be avoided?

Select	Answer
A	Temporary changes of the core permeability could result
B	RF susceptance would increase
C	Magnetic flux would increase with frequency
D	Harmonics and distortion could result

28. - E6E12

Why are high-power RF amplifier ICs and transistors sometimes mounted in ceramic packages?

Select	Answer
A	Better dissipation of heat
B	To provide a low-pass frequency response
C	High-voltage insulating ability
D	Enhanced sensitivity to light

29. - E6F14

Which of the following is true of LCD displays?

Select	Answer
A	They only display alphanumeric symbols
B	They are hard to view in high ambient light conditions
C	They may be hard view through polarized lenses
D	All of these choices are correct

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

31. - E7B12

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

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

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 inductors are in series between the input and output, and a capacitor is connected between the two inductors and ground
B	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
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	Two capacitors are in series between the input and output, and an inductor is connected between the two capacitors and ground

33. - E7D10

What is the primary reason that a high-frequency switching type high voltage power supply can be both less expensive and lighter in weight than a conventional power supply?

Select	Answer
A	The high frequency inverter design uses much smaller transformers and filter components for an equivalent power output
B	It uses a diode bridge rectifier for increased output
C	The inverter design does not require any output filtering
D	It uses a large power factor compensation capacitor to create free power from the unused portion of the AC cycle

34. - E7E01

Which of the following can be used to generate FM phone emissions?

Select	Answer
A	A reactance modulator on the oscillator
B	A balanced modulator on the oscillator
C	A reactance modulator on the final amplifier
D	A balanced modulator on the audio amplifier

35. - E7F15

Which of the following is an advantage of a Finite Impulse Response (FIR) filter vs an Infinite Impulse Response (IIR) digital filter?

Select	Answer
A	FIR filters can respond faster to impulses
B	FIR filters are easier to implement for a given set of passband rolloff requirements
C	FIR filters delay all frequency components of the signal by the same amount
D	All of these choices are correct

36. - E7G03

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

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

37. - E7H15

Which of these functions can be performed by a phase-locked loop?

Select	Answer
A	Photovoltaic conversion, optical coupling
B	Frequency synthesis, FM demodulation
C	Wide-band AF and RF power amplification
D	Comparison of two digital input signals, digital pulse counter

38. - E8A09

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

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

39. - E8B03

What is the modulation index of an FM-phone signal having a maximum frequency deviation of 3000 Hz either side of the carrier frequency when the modulating frequency is 1000 Hz?

Select	Answer
A	1000
B	3000
C	0.3
D	3

40. - E8C06

What is the necessary bandwidth of a 170-hertz shift, 300-baud ASCII transmission?

Select	Answer
A	0.3 kHz
B	0.5 kHz
C	0.1 Hz
D	1.0 kHz

41. - E8D03

How does the spread spectrum technique of frequency hopping work?

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

42. - E9A09

How is antenna efficiency calculated?

Select	Answer
A	(radiation resistance / total resistance) x 100 per cent
B	(effective radiated power / transmitter output) x 100 percent
C	(total resistance / radiation resistance) x 100 per cent
D	(radiation resistance / transmission resistance) x 100 per cent

43. - E9B09

What type of computer program technique is commonly used for modeling antennas?

Select	Answer
A	Mutual impedance analysis
B	Method of Moments
C	Calculus differentiation with respect to physical properties
D	Graphical analysis

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	Cardioid
C	A Figure-8 end-fire along the axis of the array
D	A Figure-8 broadside to the axis of the array

45. - E9D09

What is the function of a loading coil used as part of an HF mobile antenna?

Select	Answer
A	To lower the losses
B	To cancel capacitive reactance
C	To lower the Q
D	To increase the SWR bandwidth

46. - E9E01

What system matches a higher impedance transmission line to a lower impedance antenna by connecting the line to the driven element in two places spaced a fraction of a wavelength each side of element center?

Select	Answer
A	The stub matching system
B	The omega matching system
C	The delta matching system
D	The gamma matching system

47. - E9F15

What impedance does a 1/2 wavelength transmission line present to a generator when the line is open at the far end?

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

48. - E9G08

What is the process of normalization with regard to a Smith chart?

Select	Answer
A	Reassigning resistance values with regard to the reactance axis
B	Reassigning reactance values with regard to the resistance axis
C	Reassigning prime center with regard to the reactance axis
D	Reassigning impedance values with regard to the prime center

49. - E9H05

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

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

50. - E0A06

Why are there separate electric (E) and magnetic (H) field MPE limits?

Select	Answer
A	All of these choices are correct
B	The body reacts to electromagnetic radiation from both the E and H fields
C	E field and H field radiation intensity peaks can occur at different locations
D	Ground reflections and scattering make the field impedance vary with location

Figure E6-2

Figure E7-1