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

2. - E1B03

Within what distance must an amateur station protect an FCC monitoring facility from harmful interference?

Select	Answer
A	3 miles
B	10 miles
C	30 miles
D	1 mile

3. - E1C13

Which of the following is required in order to operate in accordance with CEPT rules in foreign countries where permitted?

Select	Answer
A	The U.S. embassy must approve of your operation
B	You must append "/CEPT" to your call sign
C	You must identify in the official language of the country in which you are operating
D	You must bring a copy of FCC Public Notice DA 11-221

4. - E1D07

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

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

5. - E1E03

What is a Volunteer Examiner Coordinator?

Select	Answer
A	An organization that has entered into an agreement with the FCC to coordinate amateur operator license examinations
B	The person who has entered into an agreement with the FCC to be the VE session manager
C	A person who has volunteered to prepare amateur operator license examinations
D	A person who has volunteered to administer amateur operator license examinations

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. - E2A10

Why may the received signal from an amateur satellite exhibit a rapidly repeating fading effect?

Select	Answer
A	Because of the Doppler Effect
B	Because the satellite is spinning
C	Because of the satellite's low orbital altitude
D	Because of ionospheric absorption

8. - E2B04

What is blanking in a video signal?

Select	Answer
A	Transmitting a black and white test pattern
B	Synchronization of the horizontal and vertical sync pulses
C	Turning off the scanning beam while it is traveling from right to left or from bottom to top
D	Turning off the scanning beam at the conclusion of a transmission

9. - E2C10

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

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

10. - E2D10

How can an APRS station be used to help support a public service communications activity?

Select	Answer
A	All of these choices are correct
B	An APRS station with a GPS unit can automatically transmit information to show a mobile station's position during the event
C	An APRS station with an emergency medical technician can automatically transmit medical data to the nearest hospital
D	APRS stations with General Personnel Scanners can automatically relay the participant numbers and time as they pass the check points

11. - E2E06

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

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

12. - E3A09

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

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

13. - E3B10

What is the cause of gray-line propagation?

Select	Answer
A	At twilight and sunrise, D-layer absorption is low while E-layer and F-layer propagation remains high
B	At midday, the Sun super heats the ionosphere causing increased refraction of radio waves
C	In darkness, solar absorption drops greatly while atmospheric ionization remains steady
D	At mid-afternoon, the Sun heats the ionosphere decreasing radio wave refraction and the MUF

14. - E3C10

What does the 304A solar parameter measure?

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

15. - E4A02

Which of the following parameters would a spectrum analyzer display on the vertical and horizontal axes?

Select	Answer
A	SWR and time
B	RF amplitude and frequency
C	RF amplitude and time
D	SWR and frequency

16. - E4B03

If a frequency counter with a specified accuracy of +/- 1.0 ppm reads 146,520,000 Hz, what is the most the actual frequency being measured could differ from the reading?

Select	Answer
A	165.2 Hz
B	1.4652 MHz
C	146.52 Hz
D	14.652 kHz

17. - E4C08

An SDR receiver is overloaded when input signals exceed what level?

Select	Answer
A	The maximum count value of the analog-to-digital converter
B	One-half the maximum sample rate
C	The reference voltage of the analog-to-digital converter
D	One-half the maximum sampling buffer size

18. - E4D09

What is the purpose of the preselector in a communications receiver?

Select	Answer
A	To store often-used frequencies
B	To allow selection of the optimum RF amplifier device
C	To provide a range of AGC time constants
D	To increase rejection of unwanted signals

19. - E4E10

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

Select	Answer
A	All of these choices are correct
B	The interfering signal can be several kHz in width and usually repeats at regular intervals across a HF band
C	The interfering signal may drift slowly across the HF spectrum
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. - E5A10

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

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

21. - E5B05

What happens to the magnitude of a reactance when it is converted to a susceptance?

Select	Answer
A	The sign is reversed
B	It is shifted by 90 degrees
C	It is unchanged
D	The magnitude of the susceptance is the reciprocal of the magnitude of the reactance

22. - E5C12

If you plot the impedance of a circuit using the rectangular coordinate system and find the impedance point falls on the right side of the graph on the horizontal axis, what do you know about the circuit?

Select	Answer
A	It contains resistance and inductive reactance
B	It contains resistance and capacitive reactance
C	It has to be a direct current circuit
D	It is equivalent to a pure resistance

23. - E5D06

In what direction is the magnetic field oriented about a conductor in relation to the direction of electron flow?

Select	Answer
A	In all directions; omni-directional
B	In a direction opposite to the current
C	In a direction determined by the left-hand rule
D	In the same direction as the current

24. - E6A02

Which of the following semiconductor materials contains excess free electrons?

Select	Answer
A	Insulated gate
B	Bipolar
C	P-type
D	N-type

25. - E6B13

What type of bias is required for an LED to emit light?

Select	Answer
A	Reverse bias
B	Inductive bias
C	Forward bias
D	Zero bias

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. - E6D16

What is the common name for a capacitor connected across a transformer secondary that is used to absorb transient voltage spikes?

Select	Answer
A	Snubber capacitor
B	Clipper capacitor
C	Feedback capacitor
D	Trimmer capacitor

28. - E6E03

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

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

29. - E6F05

Which describes an optical shaft encoder?

Select	Answer
A	A device for generating RTTY signals by means of a rotating light source
B	A device which measures the strength of a beam of light using analog to digital conversion
C	A device which detects rotation of a control by interrupting a light source with a patterned wheel
D	A digital encryption device often used to encrypt spacecraft control signals

30. - E7A12

What type of logic defines "0" as a high voltage?

Select	Answer
A	Positive Logic
B	Reverse Logic
C	Assertive Logic
D	Negative logic

31. - E7B15

What is one way to prevent thermal runaway in a bipolar transistor amplifier?

Select	Answer
A	All of these choices are correct
B	Neutralization
C	Use a resistor in series with the emitter
D	Select transistors with high beta

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

33. - E7D16

When several electrolytic filter capacitors are connected in series to increase the operating voltage of a power supply filter circuit, why should resistors be connected across each capacitor?

Select	Answer
A	All of these choices are correct
B	To provide a safety bleeder to discharge the capacitors when the supply is off
C	To provide a minimum load current to reduce voltage excursions at light loads
D	To equalize, as much as possible, the voltage drop across each capacitor

34. - E7E08

What are the principal frequencies that appear at the output of a mixer circuit?

Select	Answer
A	Two and four times the original frequency
B	The sum, difference and square root of the input frequencies
C	The two input frequencies along with their sum and difference frequencies
D	1.414 and 0.707 times the input frequency

35. - E7F12

What digital process is applied to I and Q signals in order to recover the baseband modulation information?

Select	Answer
A	Fast Fourier Transform
B	Decimation
C	Signal conditioning
D	Quadrature mixing

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	0.21
B	47
C	94
D	24

37. - E7H05

How is positive feedback supplied in a Pierce oscillator?

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

38. - E8A05

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

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

39. - E8B04

What is the modulation index of an FM-phone signal having a maximum carrier deviation of plus or minus 6 kHz when modulated with a 2 kHz modulating frequency?

Select	Answer
A	3
B	1/3
C	2000
D	6000

40. - E8C05

What is the necessary bandwidth of a 13-WPM international Morse code transmission?

Select	Answer
A	Approximately 13 Hz
B	Approximately 104 Hz
C	Approximately 52 Hz
D	Approximately 26 Hz

41. - E8D04

What is the primary effect of extremely short rise or fall time on a CW signal?

Select	Answer
A	The generation of key clicks
B	More difficult to copy
C	Limits data speed
D	The generation of RF harmonics

42. - E9A07

What is meant by antenna gain?

Select	Answer
A	The ratio of the amount of power radiated by an antenna compared to the transmitter output power
B	The final amplifier gain minus the transmission line losses
C	The ratio of the signal in the forward direction to that in the opposite direction
D	The ratio of the radiated signal strength of an antenna in the direction of maximum radiation to that of a reference antenna

43. - E9B06

What is the elevation angle of peak response in the antenna radiation pattern shown in Figure E9-2?

Select	Answer
A	25 degrees
B	45 degrees
C	75 degrees
D	7.5 degrees

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

45. - E9D12

Which of the following would provide the best RF ground for your station?

Select	Answer
A	An electrically short connection to a metal water pipe
B	An electrically short connection to 3 or 4 interconnected ground rods driven into the Earth
C	An electrically short connection to 3 or 4 interconnected ground rods via a series RF choke
D	A 50 ohm resistor connected to ground

46. - E9E10

Which of these choices is an effective way to match an antenna with a 100 ohm feed point impedance to a 50 ohm coaxial cable feed line?

Select	Answer
A	Insert a 1/2 wavelength piece of 300 ohm twin-lead in series between the antenna terminals and the 50 ohm feed cable
B	Connect 1/2 wavelength shorted stub of 75 ohm cable in parallel with the 50 ohm cable where it attaches to the antenna
C	Connect a 1/4-wavelength open stub of 300 ohm twin-lead in parallel with the coaxial feed line where it connects to the antenna
D	Insert a 1/4-wavelength piece of 75 ohm coaxial cable transmission line in series between the antenna terminals and the 50 ohm feed cable

47. - E9F05

What is the approximate physical length of a solid polyethylene dielectric coaxial transmission line that is electrically one-quarter wavelength long at 14.1 MHz?

Select	Answer
A	20 meters
B	3.5 meters
C	0.2 meters
D	2.3 meters

48. - E9G04

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

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

49. - E9H02

Which is generally true for low band (160 meter and 80 meter) receiving antennas?

Select	Answer
A	They must be erected at least 1/2 wavelength above the ground to attain good directivity
B	Atmospheric noise is so high that gain over a dipole is not important
C	Low loss coax transmission line is essential for good performance
D	All of these choices are correct

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

Figure E7-4

Figure E9-2