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

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1. - E1A03

With your transceiver displaying the carrier frequency of phone signals, you hear a station calling CQ on 14.349 MHz USB. Is it legal to return the call using upper sideband on the same frequency?

Select	Answer
A	No, the sideband will extend beyond the band edge
B	Yes, because you were not the station calling CQ
C	Yes, because the displayed frequency is within the 20 meter band
D	No, U.S. stations are not permitted to use phone emissions above 14.340 MHz

2. - E1B02

Which of the following factors might cause the physical location of an amateur station apparatus or antenna structure to be restricted?

Select	Answer
A	The location is near an area of political conflict
B	The location is of environmental importance or significant in American history, architecture, or culture
C	The location is in an ITU Zone designated for coordination with one or more foreign governments
D	The location is of geographical or horticultural importance

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	You must bring a copy of FCC Public Notice DA 11-221
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	The U.S. embassy must approve of your operation

4. - E1D04

What is an Earth station in the amateur satellite service?

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

5. - E1E12

What must the VE team do with the application form if the examinee does not pass the exam?

Select	Answer
A	Send the application form to the FCC and inform the FCC of the grade
B	Return the application document to the examinee
C	Destroy the application form
D	Maintain the application form with the VEC's records

6. - E1F08

Which of the following types of amateur station communications are prohibited?

Select	Answer
A	Communications that have a religious content
B	Communications that have a political content, except as allowed by the Fairness Doctrine
C	Communications in a language other than English
D	Communications transmitted for hire or material compensation, except as otherwise provided in the rules

7. - E2A06

On what band would a satellite receive signals if it were operating in mode U/V?

Select	Answer
A	29.5 MHz - 29.7 MHz
B	50.0 MHz - 50.2 MHz
C	435 MHz - 438 MHz
D	144 MHz - 146 MHz

8. - E2B14

What aspect of an amateur slow-scan television signal encodes the brightness of the picture?

Select	Answer
A	Sync frequency
B	Tone amplitude
C	Sync amplitude
D	Tone frequency

9. - E2C05

What is the function of a DX QSL Manager?

Select	Answer
A	To relay calls to and from a DX station
B	To handle the receiving and sending of confirmation cards for a DX station
C	To run a net to allow many stations to contact a rare DX station
D	To allocate frequencies for DXpeditions

10. - E2D06

Which of the following describes a method of establishing EME contacts?

Select	Answer
A	High speed CW identification to avoid fading
B	Storing and forwarding digital messages
C	Judging optimum transmission times by monitoring beacons reflected from the Moon
D	Time synchronous transmissions alternately from each station

11. - E2E11

What is the difference between direct FSK and audio FSK?

Select	Answer
A	Direct FSK applies the data signal to the transmitter VFO
B	Audio FSK can be performed anywhere in the transmit chain
C	Direct FSK uses a DC-coupled data connection
D	Audio FSK has a superior frequency response

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	1.8 MHz - 1.9 MHz
D	220 MHz - 450 MHz

13. - E3B03

What is the best time of day for transequatorial propagation?

Select	Answer
A	Afternoon or early evening
B	Late at night
C	Noon
D	Morning

14. - E3C09

How does the intensity of an X3 flare compare to that of an X2 flare?

Select	Answer
A	10 percent greater
B	Twice as great
C	Four times as great
D	50 percent greater

15. - E4A09

When using a computer's soundcard input to digitize signals, what is the highest frequency signal that can be digitized without aliasing?

Select	Answer
A	One-half the sample rate
B	The same as the sample rate
C	One-tenth the sample rate
D	It depends on how the data is stored internally

16. - E4B02

What is an advantage of using a bridge circuit to measure impedance?

Select	Answer
A	It provides an excellent match under all conditions
B	It can display results directly in Smith chart format
C	It is relatively immune to drift in the signal generator source
D	It is very precise in obtaining a signal null

17. - E4C08

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

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

18. - E4D14

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

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

19. - E4E09

What undesirable effect can occur when using an IF noise blanker?

Select	Answer
A	Received audio in the speech range might have an echo effect
B	The audio frequency bandwidth of the received signal might be compressed
C	Nearby signals may appear to be excessively wide even if they meet emission standards
D	FM signals can no longer be demodulated

20. - E5A06

What is the magnitude of the circulating current within the components of a parallel LC circuit at resonance?

Select	Answer
A	It is at a minimum
B	It is at a maximum
C	It equals 1 divided by the quantity 2 times Pi, multiplied by the square root of inductance L multiplied by capacitance C
D	It equals 2 multiplied by Pi, multiplied by frequency, multiplied by inductance

21. - E5B13

What letter is commonly used to represent susceptance?

Select	Answer
A	X
B	G
C	Y
D	B

22. - E5C14

Which point on Figure E5-2 best represents the impedance of a series circuit consisting of a 400 ohm resistor and a 38 picofarad capacitor at 14 MHz?

Select	Answer
A	Point 5
B	Point 2
C	Point 4
D	Point 6

23. - E5D17

How many watts are consumed in a circuit having a power factor of 0.6 if the input is 200VAC at 5 amperes?

Select	Answer
A	200 watts
B	1000 watts
C	1600 watts
D	600 watts

24. - E6A15

Which semiconductor material contains excess holes in the outer shell of electrons?

Select	Answer
A	P-type
B	Bipolar-type
C	N-type
D	Superconductor-type

25. - E6B04

What type of semiconductor device is designed for use as a voltage-controlled capacitor?

Select	Answer
A	Zener diode
B	Silicon-controlled rectifier
C	Tunnel diode
D	Varactor diode

26. - E6C10

In Figure E6-5, what is the schematic symbol for a NOR gate?

Select	Answer
A	3
B	4
C	1
D	2

27. - E6D06

What core material property determines the inductance of a toroidal inductor?

Select	Answer
A	Reactivity
B	Permeability
C	Thermal impedance
D	Resistance

28. - E6E12

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

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

29. - E6F07

What is a solid state relay?

Select	Answer
A	A passive delay line
B	A mechanical relay that latches in the on or off state each time it is pulsed
C	A device that uses semiconductors to implement the functions of an electromechanical relay
D	A relay using transistors to drive the relay coil

30. - E7A05

Which of the following is a circuit that continuously alternates between two states without an external clock?

Select	Answer
A	Astable multivibrator
B	Monostable multivibrator
C	J-K flip-flop
D	T flip-flop

31. - E7B08

How can an RF power amplifier be neutralized?

Select	Answer
A	By reducing the driving power
B	By feeding a 180-degree out-of-phase portion of the output back to the input
C	By increasing the driving power
D	By feeding an in-phase component of the output back to the input

32. - E7C07

What kind of filter would you use to attenuate an interfering carrier signal while receiving an SSB transmission?

Select	Answer
A	A band-pass filter
B	A Pi-network filter
C	A notch filter
D	An all-pass filter

33. - E7D14

What is one purpose of a "bleeder" resistor in a conventional unregulated power supply?

Select	Answer
A	To improve output voltage regulation
B	To cut down on waste heat generated by the power supply
C	To balance the low-voltage filament windings
D	To boost the amount of output current

34. - E7E08

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

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

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. - E7G01

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

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

37. - E7H11

What are the major spectral impurity components of direct digital synthesizers?

Select	Answer
A	Nyquist limit noise
B	Spurious signals at discrete frequencies
C	Digital conversion noise
D	Broadband noise

38. - E8A10

What is the purpose of a low pass filter used in conjunction with a digital-to-analog converter?

Select	Answer
A	All of these choices are correct
B	Remove harmonics from the output caused by the discrete analog levels generated
C	Lower the input bandwidth to increase the effective resolution
D	Improve accuracy by removing out of sequence codes from the input

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	3000
B	3
C	1000
D	0.3

40. - E8C06

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

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

41. - E8D02

What spread spectrum communications technique uses a high speed binary bit stream to shift the phase of an RF carrier?

Select	Answer
A	Binary phase-shift keying
B	Direct sequence
C	Frequency hopping
D	Phase compandored spread spectrum

42. - E9A03

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

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

43. - E9B06

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

Select	Answer
A	75 degrees
B	45 degrees
C	7.5 degrees
D	25 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	Cardioid
B	Omni-directional
C	A Figure-8 broadside to the axis of the array
D	A Figure-8 end-fire along the axis of the array

45. - E9D08

What happens as the Q of an antenna increases?

Select	Answer
A	Gain is reduced
B	More common-mode current is present on the feed line
C	SWR bandwidth decreases
D	SWR bandwidth increases

46. - E9E07

What term best describes the interactions at the load end of a mismatched transmission line?

Select	Answer
A	Velocity factor
B	Dielectric constant
C	Reflection coefficient
D	Characteristic impedance

47. - E9F03

Why is the physical length of a coaxial cable transmission line shorter than its electrical length?

Select	Answer
A	Electrical signals move more slowly in a coaxial cable than in air
B	The surge impedance is higher in a parallel feed line
C	Skin effect is less pronounced in the coaxial cable
D	The characteristic impedance is higher in a parallel feed line

48. - E9G08

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

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

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

Figure E5-2

Figure E6-5

Figure E9-2