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

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1. - E1A12

With your transceiver displaying the carrier frequency of CW signals, you hear a DX station's CQ on 3.500 MHz. Is it legal to return the call using CW on the same frequency?

Select	Answer
A	No, U.S. stations are not permitted to use CW emissions below 3.525 MHz
B	Yes, the displayed frequency is within the 80 meter CW band segment
C	No, one of the sidebands of the CW signal will be out of the band
D	Yes, the DX station initiated the contact

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 obtain a construction permit from the airport zoning authority
B	You must file an Environmental Impact Statement with the EPA before construction begins
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	No special rules apply if your antenna structure will be less than 300 feet in height

3. - E1C01

What is a remotely controlled station?

Select	Answer
A	A station controlled indirectly through a control link
B	A station operated away from its regular home location
C	A station controlled by someone other than the licensee
D	A station operating under automatic control

4. - E1D03

What is a telecommand station in the amateur satellite service?

Select	Answer
A	An amateur station that transmits telemetry consisting of measurements of upper atmosphere
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 that transmits communications to initiate, modify or terminate functions of a space station
D	An amateur station located more than 50 km above the Earth's surface

5. - E1E14

For which types of out-of-pocket expenses do the Part 97 rules state that VEs and VECs may be reimbursed?

Select	Answer
A	No expenses are authorized for reimbursement
B	Preparing, processing, administering and coordinating an examination for an amateur radio license
C	Providing amateur operator license examination preparation training materials
D	Teaching an amateur operator license examination preparation course

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	1.5 W
C	1 W
D	1.5 kW

7. - E2A02

What is the direction of a descending pass for an amateur satellite?

Select	Answer
A	From north to south
B	From east to west
C	From west to east
D	From south to north

8. - E2B18

On which of the following frequencies is one likely to find FM ATV transmissions?

Select	Answer
A	1255 MHz
B	14.230 MHz
C	52.525 MHz
D	29.6 MHz

9. - E2C08

Which of the following contacts may be confirmed through the U.S. QSL bureau system?

Select	Answer
A	Repeater contacts between U.S. club members
B	Special event contacts between stations in the U.S.
C	Contacts between a U.S. station and a non-U.S. station
D	Contacts using tactical call signs

10. - E2D09

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

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

11. - E2E05

Which type of digital mode does not support keyboard-to-keyboard operation?

Select	Answer
A	MFSK
B	PSK31
C	RTTY
D	Winlink

12. - E3A13

Which emission mode is best for aurora propagation?

Select	Answer
A	SSB
B	FM
C	RTTY
D	CW

13. - E3B07

Which of the following could account for hearing an echo on the received signal of a distant station?

Select	Answer
A	Meteor scatter
B	Transmit frequency is higher than the MUF
C	High D layer absorption
D	Receipt of a signal by more than one path

14. - E3C05

What orientation of Bz (B sub z) increases the likelihood that incoming particles from the Sun will cause disturbed conditions?

Select	Answer
A	Southward
B	Eastward
C	Northward
D	Westward

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

17. - E4C02

Which of the following portions of a receiver can be effective in eliminating image signal interference?

Select	Answer
A	A notch filter
B	A front-end filter or pre-selector
C	A properly adjusted product detector
D	A narrow IF filter

18. - E4D02

Which of the following describes two problems caused by poor dynamic range in a communications receiver?

Select	Answer
A	Cross-modulation of the desired signal and desensitization from strong adjacent signals
B	Cross-modulation of the desired signal and insufficient audio power to operate the speaker
C	Oscillator instability requiring frequent retuning and loss of ability to recover the opposite sideband
D	Oscillator instability and severe audio distortion of all but the strongest received signals

19. - E4E15

Which of the following can cause shielded cables to radiate or receive interference?

Select	Answer
A	Use of braided shielding material
B	Low inductance ground connections at both ends of the shield
C	Tying all ground connections to a common point resulting in differential mode currents in the shield
D	Common mode currents on the shield and conductors

20. - E5A02

What is resonance in an electrical circuit?

Select	Answer
A	The lowest frequency that will pass current
B	The frequency at which the reactive impedance equals the resistive impedance
C	The frequency at which the capacitive reactance equals the inductive reactance
D	The highest frequency that will pass current

21. - E5B06

What is susceptance?

Select	Answer
A	The inverse of reactance
B	A measure of the efficiency of a transformer
C	The magnetic impedance of a circuit
D	The ratio of magnetic field to electric field

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 6
C	Point 4
D	Point 2

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

24. - E6A04

What is the name given to an impurity atom that adds holes to a semiconductor crystal structure?

Select	Answer
A	Insulator impurity
B	Donor impurity
C	N-type impurity
D	Acceptor impurity

25. - E6B09

What is a common use for point contact diodes?

Select	Answer
A	As a constant current source
B	As a high voltage rectifier
C	As a constant voltage source
D	As an RF detector

26. - E6C02

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

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

27. - E6D06

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

Select	Answer
A	Thermal impedance
B	Resistance
C	Reactivity
D	Permeability

28. - E6E01

Which of the following is true of a charge-coupled device (CCD)?

Select	Answer
A	It is a CMOS analog-to-digital converter
B	It samples an analog signal and passes it in stages from the input to the output
C	It is used in a battery charger circuit
D	Its phase shift changes rapidly with frequency

29. - E6F09

What is the efficiency of a photovoltaic cell?

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

30. - E7A04

How many flip-flops are required to divide a signal frequency by 4?

Select	Answer
A	8
B	1
C	2
D	4

31. - E7B14

Why are switching amplifiers more efficient than linear amplifiers?

Select	Answer
A	The power transistor is at saturation or cut off most of the time, resulting in low power dissipation
B	Linear amplifiers have high gain resulting in higher harmonic content
C	Switching amplifiers operate at higher voltages
D	Switching amplifiers use push-pull circuits

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

33. - E7D07

What is the purpose of C2 in the circuit shown in Figure E7-3?

Select	Answer
A	It bypasses hum around D1
B	To provide fixed DC bias for Q1
C	To self-resonate at the hum frequency
D	It is a brute force filter for the output

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	1.414 and 0.707 times the input frequency
C	The sum, difference and square root of the input frequencies
D	The two input frequencies along with their sum and difference frequencies

35. - E7F14

Which of the following would allow a digital signal processing filter to create a sharper filter response?

Select	Answer
A	Double-precision math routines
B	Complex phasor representations
C	More taps
D	Higher data rate

36. - E7G01

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

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

37. - E7H05

How is positive feedback supplied in a Pierce oscillator?

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

38. - E8A06

What is the approximate ratio of PEP-to-average power in a typical single-sideband phone signal?

Select	Answer
A	25 to 1
B	100 to 1
C	1 to 1
D	2.5 to 1

39. - E8B05

What is the deviation ratio of an FM-phone signal having a maximum frequency swing of plus-or-minus 5 kHz when the maximum modulation frequency is 3 kHz?

Select	Answer
A	0.6
B	1.67
C	60
D	0.167

40. - E8C09

Which is the name of a digital code where each preceding or following character changes by only one bit?

Select	Answer
A	Gray code
B	Excess 3 code
C	Binary Coded Decimal Code
D	Extended Binary Coded Decimal Interchange Code

41. - E8D08

What parameter might indicate that excessively high input levels are causing distortion in an AFSK signal?

Select	Answer
A	Baud rate
B	Intermodulation Distortion (IMD)
C	Signal to noise ratio
D	Repeat Request Rate (RRR)

42. - E9A08

What is meant by antenna bandwidth?

Select	Answer
A	Antenna length divided by the number of elements
B	The frequency range over which an antenna satisfies a performance requirement
C	The angle formed between two imaginary lines drawn through the element ends
D	The angle between the half-power radiation points

43. - E9B04

What may occur when a directional antenna is operated at different frequencies within the band for which it was designed?

Select	Answer
A	The E-field and H-field patterns may reverse
B	Element spacing limits could be exceeded
C	Feed point impedance may become negative
D	The gain may change depending on frequency

44. - E9C05

What is an OCFD antenna?

Select	Answer
A	A multiband dipole antenna using one-way circular polarization for frequency diversity
B	A remotely tunable dipole antenna using orthogonally controlled frequency diversity
C	An eight band dipole antenna using octophase filters
D	A dipole feed approximately 1/3 the way from one end with a 4:1 balun to provide multiband operation

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 does not change
C	Gain increases by 3 dB
D	Gain is multiplied by 0.707

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	Connect 1/2 wavelength shorted stub of 75 ohm cable in parallel with the 50 ohm cable where it attaches to the antenna
B	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
C	Insert a 1/2 wavelength piece of 300 ohm twin-lead in series between the antenna terminals and the 50 ohm feed cable
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. - E9F11

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

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

48. - E9G11

How are the wavelength scales on a Smith chart calibrated?

Select	Answer
A	In fractions of antenna electrical wavelength
B	In fractions of transmission line electrical wavelength
C	In fractions of antenna electrical frequency
D	In fractions of transmission line electrical frequency

49. - E9H06

What is the triangulation method of direction finding?

Select	Answer
A	Antenna headings from several different receiving locations are used to locate the signal source
B	The geometric angles of sky waves from the source are used to determine its position
C	A fixed receiving station uses three different antennas to plot the location of the signal source
D	A fixed receiving station plots three headings to the signal source

50. - E0A05

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

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

Figure E5-2

Figure E7-3