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

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

2. - E1B08

What limitations may the FCC place on an amateur station if its signal causes interference to domestic broadcast reception, assuming that the receivers involved are of good engineering design?

Select	Answer
A	The amateur station must cease operation
B	The amateur station must cease operation on all frequencies above 30 MHz
C	The amateur station must cease operation on all frequencies below 30 MHz
D	The amateur station must avoid transmitting during certain hours on frequencies that cause the interference

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 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	The use of a control link between a control point and a locally controlled station

4. - E1D04

What is an Earth station in the amateur satellite service?

Select	Answer
A	An amateur station within 50 km of the Earth's surface intended for communications with amateur stations by means of objects in space
B	An amateur station that is not able to communicate using amateur satellites
C	An amateur station that transmits telemetry consisting of measurement of upper atmosphere
D	Any amateur station on the surface of the Earth

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 70%
C	Minimum passing score of 80%
D	Minimum passing score of 77%

6. - E1F10

What is the maximum permitted transmitter peak envelope power for an amateur station transmitting spread spectrum communications?

Select	Answer
A	10 W
B	1 W
C	1.5 kW
D	1.5 W

7. - E2A07

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

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

8. - E2B10

Which of the following is an acceptable bandwidth for Digital Radio Mondiale (DRM) based voice or SSTV digital transmissions made on the HF amateur bands?

Select	Answer
A	20 KHz
B	3 KHz
C	10 KHz
D	15 KHz

9. - E2C13

What indicator is required to be used by U.S.-licensed operators when operating a station via remote control where the transmitter is located in the U.S.?

Select	Answer
A	/R# where # is the district of the remote station
B	/ followed by the USPS two letter abbreviation for the state in which the remote station is located
C	No additional indicator is required
D	The ARRL section of the remote station

10. - E2D09

Which of these digital modes has the fastest data throughput under clear communication conditions?

Select	Answer
A	170 Hz shift, 45 baud RTTY
B	AMTOR
C	PSK31
D	300 baud packet

11. - E2E04

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

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

12. - E3A15

What is an electromagnetic wave?

Select	Answer
A	A wave consisting of two electric fields at parallel right angles to each other
B	A wave consisting of two magnetic fields at right angles to each other
C	A wave consisting of an electric field and a magnetic field oscillating at right angles to each other
D	A wave of alternating current, in the core of an electromagnet

13. - E3B05

Which amateur bands typically support long-path propagation?

Select	Answer
A	160 meters to 40 meters
B	6 meters to 2 meters
C	30 meters to 10 meters
D	160 meters to 10 meters

14. - E3C10

What does the 304A solar parameter measure?

Select	Answer
A	The solar wind velocity at 304 degrees from the solar equator, correlated to solar activity
B	The solar emission at 304 GHz, correlated to X-Ray flare levels
C	UV emissions at 304 angstroms, correlated to solar flux index
D	The ratio of X-Ray flux to radio flux, correlated to sunspot number

15. - E4A04

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

Select	Answer
A	Amount of memory on the soundcard
B	Q of the interface of the interface circuit
C	Analog-to-digital conversion speed of 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	75 watts
D	25 watts

17. - E4C15

What is usually the primary source of noise that is heard from an HF receiver with an antenna connected?

Select	Answer
A	Detector noise
B	Atmospheric noise
C	Receiver front-end noise
D	Induction motor noise

18. - E4D10

What does a third-order intercept level of 40 dBm mean with respect to receiver performance?

Select	Answer
A	Signals less than 40 dBm will not generate audible third-order intermodulation products
B	A pair of 40 dBm signals will theoretically generate a third-order intermodulation product with the same level as the input signals
C	A pair of 1 mW input signals will produce a third-order intermodulation product which is 40 dB stronger than the input signal
D	The receiver can tolerate signals up to 40 dB above the noise floor without producing third-order intermodulation products

19. - E4E07

How can you determine if line noise interference is being generated within your home?

Select	Answer
A	By observing the AC power line waveform with an oscilloscope
B	By turning off the AC power line main circuit breaker and listening on a battery operated radio
C	By checking the power line voltage with a time domain reflectometer
D	By observing the AC power line voltage with a spectrum analyzer

20. - E5A08

What is the phase relationship between the current through and the voltage across a series resonant circuit at resonance?

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

21. - E5B11

What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 25 ohms, R is 100 ohms, and XL is 50 ohms?

Select	Answer
A	14 degrees with the voltage lagging the current
B	14 degrees with the voltage leading the current
C	76 degrees with the voltage lagging the current
D	76 degrees with the voltage leading the current

22. - E5C03

Which of the following represents an inductive reactance in polar coordinates?

Select	Answer
A	A negative real part
B	A negative phase angle
C	A positive phase angle
D	A positive real part

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	704 W
B	355 W
C	252 W
D	1.42 mW

24. - E6A17

What are the names of the three terminals of a field-effect transistor?

Select	Answer
A	Gate, drain, source
B	Emitter, base, collector
C	Emitter, base 1, base 2
D	Gate 1, gate 2, drain

25. - E6B05

What characteristic of a PIN diode makes it useful as an RF switch or attenuator?

Select	Answer
A	A large region of intrinsic material
B	Ability to dissipate large amounts of power
C	Extremely high reverse breakdown voltage
D	Reverse bias controls its forward voltage drop

26. - E6C02

What happens when the level of a comparator's input signal crosses the threshold?

Select	Answer
A	The comparator enters latch-up
B	The comparator changes its output state
C	The IC input can be damaged
D	The feedback loop becomes unstable

27. - E6D03

Which of the following is an aspect of the piezoelectric effect?

Select	Answer
A	Mechanical deformation of material by the application of a magnetic field
B	Increased conductivity in the presence of light
C	Mechanical deformation of material by the application of a voltage
D	Generation of electrical energy in the presence of light

28. - E6E07

Which of the following is typically used to construct a MMIC-based microwave amplifier?

Select	Answer
A	Wave-soldering construction
B	Point-to-point construction
C	Ground-plane construction
D	Microstrip construction

29. - E6F08

Why are optoisolators often used in conjunction with solid state circuits when switching 120VAC?

Select	Answer
A	Optoisolators provide impedance matching between the control circuit and power circuit
B	Optoisolators eliminate the effects of reflected light in the control circuit
C	Optoisolators provide a low impedance link between a control circuit and a power circuit
D	Optoisolators provide a very high degree of electrical isolation between a control circuit and the circuit being switched

30. - E7A06

What is a characteristic of a monostable multivibrator?

Select	Answer
A	It maintains a constant output voltage, regardless of variations in the input voltage
B	It produces a continuous square wave oscillating between 1 and 0
C	It stores one bit of data in either a 0 or 1 state
D	It switches momentarily to the opposite binary state and then returns to its original state after a set time

31. - E7B11

In Figure E7-1, what is the purpose of R3?

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

33. - E7D03

What device is typically used as a stable reference voltage in a linear voltage regulator?

Select	Answer
A	A Zener diode
B	A tunnel diode
C	An SCR
D	A varactor diode

34. - E7E10

How does a diode detector function?

Select	Answer
A	By breakdown of the Zener voltage
B	By sensing the change of reactance in the diode with respect to frequency
C	By mixing signals with noise in the transition region of the diode
D	By rectification and filtering of RF signals

35. - E7F11

What sets the minimum detectable signal level for an SDR in the absence of atmospheric or thermal noise?

Select	Answer
A	Sample clock phase noise
B	Reference voltage level and sample width in bits
C	Data storage transfer rate
D	Missing codes and jitter

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	0.21
C	24
D	47

37. - E7H04

How is positive feedback supplied in a Colpitts oscillator?

Select	Answer
A	Through a tapped coil
B	Through link coupling
C	Through a neutralizing capacitor
D	Through a capacitive divider

38. - E8A05

What would be the most accurate way of measuring the RMS voltage of a complex waveform?

Select	Answer
A	By measuring the heating effect in a known resistor
B	By using an absorption wave meter
C	By using a grid dip meter
D	By measuring the voltage with a D'Arsonval meter

39. - E8B02

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

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

40. - E8C10

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

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

41. - E8D09

What is considered a good minimum IMD level for an idling PSK signal?

Select	Answer
A	-30 dB
B	+10 dB
C	+15 dB
D	-20 dB

42. - E9A16

What is the effective radiated power relative to a dipole of a repeater station with 200 watts transmitter power output, 4 dB feed line loss, 3.2 dB duplexer loss, 0.8 dB circulator loss, and 10 dBd antenna gain?

Select	Answer
A	300 watts
B	317 watts
C	2000 watts
D	126 watts

43. - E9B03

In the antenna radiation pattern shown in Figure E9-1, what is the front-to-side ratio?

Select	Answer
A	14 dB
B	12 dB
C	24 dB
D	18 dB

44. - E9C07

What is the approximate feed point impedance at the center of a two-wire folded dipole antenna?

Select	Answer
A	72 ohms
B	300 ohms
C	450 ohms
D	50 ohms

45. - E9D01

How does the gain of an ideal parabolic dish antenna change when the operating frequency is doubled?

Select	Answer
A	Gain increases by 6 dB
B	Gain is multiplied by 0.707
C	Gain does not change
D	Gain increases by 3 dB

46. - E9E13

What is a use for a Wilkinson divider?

Select	Answer
A	It is used to feed low-impedance loads from a high-impedance source
B	It is used to divide power equally between two 50 ohm loads while maintaining 50 ohm input impedance
C	It divides the operating frequency of a transmitter signal so it can be used on a lower frequency band
D	It is used to feed high-impedance antennas from a low-impedance source

47. - E9F10

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

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

48. - E9G10

What do the arcs on a Smith chart represent?

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

49. - E9H01

When constructing a Beverage antenna, which of the following factors should be included in the design to achieve good performance at the desired frequency?

Select	Answer
A	It should be one or more wavelengths long
B	It must be mounted more than 1 wavelength above ground
C	It should be configured as a four-sided loop
D	Its overall length must not exceed 1/4 wavelength

50. - E0A03

Which of the following would be a practical way to estimate whether the RF fields produced by an amateur radio station are within permissible MPE limits?

Select	Answer
A	Use a calibrated antenna analyzer
B	Use a hand calculator plus Smith-chart equations to calculate the fields
C	Use an antenna modeling program to calculate field strength at accessible locations
D	All of the choices are correct

Figure E7-1

Figure E7-4

Figure E9-1