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. - E1A09

What is the first action you should take if your digital message forwarding station inadvertently forwards a communication that violates FCC rules?

Select	Answer
A	Notify the originating station that the communication does not comply with FCC rules
B	Notify the nearest FCC Field Engineer's office
C	Discontinue forwarding the communication as soon as you become aware of it
D	Discontinue forwarding all messages

2. - E1B03

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

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

3. - E1C06

Which of the following statements concerning remotely controlled amateur stations is true?

Select	Answer
A	A control operator must be present at the control point
B	Repeater and auxiliary stations may not be remotely controlled
C	A control operator need not be present at the control point
D	Only Extra Class operators may be the control operator of a remote station

4. - E1D06

Which of the following is a requirement of a space station?

Select	Answer
A	The space station must be capable of terminating transmissions by telecommand when directed by the FCC
B	The space station must cease all transmissions after 5 years
C	All of these choices are correct
D	The space station must be capable of changing its orbit whenever such a change is ordered by NASA

5. - E1E04

Which of the following best describes the Volunteer Examiner accreditation process?

Select	Answer
A	The amateur operator applying must pass a VE examination administered by the FCC Enforcement Bureau
B	The procedure by which a VEC confirms that the VE applicant meets FCC requirements to serve as an examiner
C	Each General, Advanced and Amateur Extra Class operator is automatically accredited as a VE when the license is granted
D	The prospective VE obtains accreditation from the FCC

6. - E1F07

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

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

7. - E2A13

What type of satellite appears to stay in one position in the sky?

Select	Answer
A	Geomagnetic
B	HEO
C	LEO
D	Geostationary

8. - E2B15

What signals SSTV receiving equipment to begin a new picture line?

Select	Answer
A	Specific tone amplitudes
B	Specific tone frequencies
C	A two-tone signal
D	Elapsed time

9. - E2C06

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

Select	Answer
A	At the top of each band, usually in a segment reserved for contests
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	In the middle of each band, usually on the national calling frequency

10. - E2D13

What type of modulation is used for JT65 contacts?

Select	Answer
A	IEEE 802.11
B	PSK
C	RTTY
D	Multi-tone AFSK

11. - E2E04

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

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

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. - E3B02

What is the approximate maximum range for signals using transequatorial propagation?

Select	Answer
A	7500 miles
B	5000 miles
C	1000 miles
D	2500 miles

14. - E3C14

Why does the radio-path horizon distance exceed the geometric horizon?

Select	Answer
A	D-region skip
B	Downward bending due to aurora refraction
C	Downward bending due to density variations in the atmosphere
D	E-region skip

15. - E4A02

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

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

16. - E4B14

What happens if a dip meter is too tightly coupled to a tuned circuit being checked?

Select	Answer
A	Cross modulation occurs
B	Harmonics are generated
C	A less accurate reading results
D	Intermodulation distortion occurs

17. - E4C09

Which of the following choices is a good reason for selecting a high frequency for the design of the IF in a conventional HF or VHF communications receiver?

Select	Answer
A	Improved receiver noise figure
B	Fewer components in the receiver
C	Easier for front-end circuitry to eliminate image responses
D	Reduced drift

18. - E4D10

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

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

19. - E4E04

How can conducted and radiated noise caused by an automobile alternator be suppressed?

Select	Answer
A	By installing a high-pass filter in series with the radio's power lead and a low-pass filter in parallel with the field lead
B	By installing a noise suppression resistor and a blocking capacitor in both leads
C	By installing filter capacitors in series with the DC power lead and a blocking capacitor in the field lead
D	By connecting the radio's power leads directly to the battery and by installing coaxial capacitors in line with the alternator leads

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	Reactance of the inductance times the reactance of the capacitance
C	Resistance divided by the reactance of either the inductance or capacitance
D	Reactance of either the inductance or capacitance times the resistance

21. - E5B04

What is the time constant of a circuit having two 220 microfarad capacitors and two 1 megohm resistors, all in parallel?

Select	Answer
A	55 seconds
B	110 seconds
C	440 seconds
D	220 seconds

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 is equivalent to a pure resistance
C	It has to be a direct current circuit
D	It contains resistance and capacitive reactance

23. - E5D04

Why are short connections necessary at microwave frequencies?

Select	Answer
A	To reduce noise figure
B	To reduce phase shift along the connection
C	Because of ground reflections
D	To increase neutralizing resistance

24. - E6A10

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

Select	Answer
A	2
B	5
C	6
D	4

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	Capacitance of an RF coupling capacitor
C	A sub-harmonic pump signal
D	Forward DC bias current

26. - E6C12

What is BiCMOS logic?

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

27. - E6D10

What is a primary advantage of using a toroidal core instead of a solenoidal core in an inductor?

Select	Answer
A	Toroidal cores make it easier to couple the magnetic energy into other components
B	Toroidal cores have lower Q characteristics
C	Toroidal cores exhibit greater hysteresis
D	Toroidal cores confine most of the magnetic field within the core material

28. - E6E02

Which of the following device packages is a through-hole type?

Select	Answer
A	PLCC
B	SOT
C	DIP
D	Ball grid array

29. - E6F09

What is the efficiency of a photovoltaic cell?

Select	Answer
A	The open-circuit voltage divided by the short-circuit current under full illumination
B	The relative fraction of light that is converted to current
C	The effective payback period
D	The output RF power divided by the input DC power

30. - E7A10

What is a truth table?

Select	Answer
A	A table of logic symbols that indicate the logic states of an op-amp
B	A list of inputs and corresponding outputs for a digital device
C	A table of logic symbols that indicate the high logic states of an op-amp
D	A diagram showing logic states when the digital device output is true

31. - E7B10

In Figure E7-1, what is the purpose of R1 and R2?

Select	Answer
A	Feedback
B	Self bias
C	Fixed bias
D	Load resistors

32. - E7C03

What advantage does a Pi-L-network have over a regular Pi-network for impedance matching between the final amplifier of a vacuum-tube transmitter and an antenna?

Select	Answer
A	Lower losses
B	Greater transformation range
C	Higher efficiency
D	Greater harmonic suppression

33. - E7D01

What is one characteristic of a linear electronic voltage regulator?

Select	Answer
A	It eliminates the need for a pass transistor
B	The conduction of a control element is varied to maintain a constant output voltage
C	It has a ramp voltage as its output
D	The control element duty cycle is proportional to the line or load conditions

34. - E7E05

What circuit is added to an FM transmitter to boost the higher audio frequencies?

Select	Answer
A	An audio prescaler
B	A de-emphasis network
C	A heterodyne suppressor
D	A pre-emphasis network

35. - E7F16

How might the sampling rate of an existing digital signal be adjusted by a factor of 3/4?

Select	Answer
A	Multiply each sample value by a factor of 3/4
B	Interpolate by a factor of three, then decimate by a factor of four
C	Change the gain by a factor of 3/4
D	Add 3 to each input value and subtract 4 from each output value

36. - E7G03

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

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

37. - E7H02

Which describes a microphonic?

Select	Answer
A	An IC used for amplifying microphone signals
B	Changes in oscillator frequency due to mechanical vibration
C	Excess loading of the microphone by an oscillator
D	Distortion caused by RF pickup on the microphone cable

38. - E8A04

What is "dither" with respect to analog to digital converters?

Select	Answer
A	A small amount of noise added to the input signal to allow more precise representation of a signal over time
B	A method of decimation by randomly skipping samples
C	An abnormal condition where the converter cannot settle on a value to represent the signal
D	An error caused by irregular quantization step size

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	2000
B	3
C	6000
D	1/3

40. - E8C03

When performing phase shift keying, why is it advantageous to shift phase precisely at the zero crossing of the RF carrier?

Select	Answer
A	This results in the least possible transmitted bandwidth for the particular mode
B	It improves carrier suppression
C	All of these choices are correct
D	It is easier to demodulate with a conventional, non-synchronous detector

41. - E8D04

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

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

42. - E9A11

Which of the following factors determines ground losses for a ground-mounted vertical antenna operating in the 3 MHz to 30 MHz range?

Select	Answer
A	The standing wave ratio
B	Take-off angle
C	Distance from the transmitter
D	Soil conductivity

43. - E9B12

What is the far field of an antenna?

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

44. - E9C10

Which of the following describes a Zepp antenna?

Select	Answer
A	A vertical array capable of quickly changing the direction of maximum radiation by changing phasing lines
B	A dipole constructed from zip cord
C	An omni-directional antenna commonly used for satellite communications
D	An end fed dipole antenna

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 SWR is reduced
D	The front-to-back ratio decreases

46. - E9E04

What is the purpose of the series capacitor in a gamma-type antenna matching network?

Select	Answer
A	To cancel the inductive reactance of the matching network
B	To provide a rejection notch that prevents the radiation of harmonics
C	To transform the antenna impedance to a higher value
D	To provide DC isolation between the feed line and the antenna

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 higher velocity factor
C	Foam dielectric has lower safe operating voltage limits
D	Foam dielectric has lower loss per unit of length

48. - E9G01

Which of the following can be calculated using a Smith chart?

Select	Answer
A	Radiation resistance
B	Impedance along transmission lines
C	Radio propagation
D	Antenna radiation pattern

49. - E9H02

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

Select	Answer
A	All of these choices are correct
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	They must be erected at least 1/2 wavelength above the ground to attain good directivity

50. - E0A05

What is one of the potential hazards of using microwaves in the amateur radio bands?

Select	Answer
A	The extremely high frequency energy can damage the joints of antenna structures
B	Microwaves often travel long distances by ionospheric reflection
C	The high gain antennas commonly used can result in high exposure levels
D	Microwaves are ionizing radiation

Figure E6-2

Figure E7-1