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

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1. - E1A02

When using a transceiver that displays the carrier frequency of phone signals, which of the following displayed frequencies represents the lowest frequency at which a properly adjusted LSB emission will be totally within the band?

Select	Answer
A	The exact lower band edge
B	300 Hz above the lower band edge
C	1 kHz above the lower band edge
D	3 kHz above the lower band edge

2. - E1B10

What frequencies are authorized to an amateur station operating under RACES rules?

Select	Answer
A	Specific local government channels
B	All amateur service frequencies authorized to the control operator
C	Military Auxiliary Radio System (MARS) channels
D	Specific segments in the amateur service MF, HF, VHF and UHF bands

3. - E1C09

Which of these ranges of frequencies is available for an automatically controlled repeater operating below 30 MHz?

Select	Answer
A	24.940 MHz - 24.990 MHz
B	18.110 MHz - 18.168 MHz
C	29.500 MHz - 29.700 MHz
D	10.100 MHz - 10.150 MHz

4. - E1D09

Which UHF amateur service bands have frequencies available for a space station?

Select	Answer
A	33 cm and 13 cm
B	70 cm and 33 cm
C	70 cm only
D	70 cm and 13 cm

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

6. - E1F06

Under what circumstances might the FCC issue a Special Temporary Authority (STA) to an amateur station?

Select	Answer
A	To provide temporary operation while awaiting normal licensing
B	To provide for experimental amateur communications
C	To allow regular operation on Land Mobile channels
D	To provide additional spectrum for personal use

7. - E2A11

What type of antenna can be used to minimize the effects of spin modulation and Faraday rotation?

Select	Answer
A	A log-periodic dipole array
B	An isotropic antenna
C	A linearly polarized antenna
D	A circularly polarized antenna

8. - E2B13

How many lines are commonly used in each frame of an amateur slow-scan color television picture?

Select	Answer
A	60 or 100
B	180 or 360
C	128 or 256
D	30 or 60

9. - E2C09

What type of equipment is commonly used to implement a ham radio mesh network?

Select	Answer
A	A 2 meter VHF transceiver with a 1200 baud modem
B	An optical cable connection between the USB ports of 2 separate computers
C	A 440 MHz transceiver with a 9600 baud modem
D	A standard wireless router running custom software

10. - E2D09

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

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

11. - E2E01

Which type of modulation is common for data emissions below 30 MHz?

Select	Answer
A	FSK
B	Pulse modulation
C	Spread spectrum
D	DTMF tones modulating an FM signal

12. - E3A03

When scheduling EME contacts, which of these conditions will generally result in the least path loss?

Select	Answer
A	When the Moon is full
B	When the Moon is at perigee
C	When the Moon is at apogee
D	When the MUF is above 30 MHz

13. - E3B14

What happens to linearly polarized radio waves that split into ordinary and extraordinary waves in the ionosphere?

Select	Answer
A	They become elliptically polarized
B	They become phase-locked
C	They are bent toward the magnetic poles
D	Their polarization is randomly modified

14. - E3C08

What does the space weather term G5 mean?

Select	Answer
A	Moderate solar wind
B	Waning sunspot numbers
C	Very low solar activity
D	An extreme geomagnetic storm

15. - E4A04

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

Select	Answer
A	All of these choices are correct
B	Q of the interface of the interface circuit
C	Analog-to-digital conversion speed of the soundcard
D	Amount of memory on the soundcard

16. - E4B02

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

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

17. - E4C17

Which of the following has the largest effect on an SDR receiver's linearity?

Select	Answer
A	Analog-to-digital converter sample width in bits
B	RAM speed used for data storage
C	Anti-aliasing input filter bandwidth
D	CPU register width in bits

18. - E4D12

What is the term for the reduction in receiver sensitivity caused by a strong signal near the received frequency?

Select	Answer
A	Quieting
B	Cross-modulation interference
C	Squelch gain rollback
D	Desensitization

19. - E4E06

What is a major cause of atmospheric static?

Select	Answer
A	Solar radio frequency emissions
B	Thunderstorms
C	Meteor showers
D	Geomagnetic storms

20. - E5A03

What is the magnitude of the impedance of a series RLC circuit at resonance?

Select	Answer
A	Approximately equal to capacitive reactance
B	Approximately equal to circuit resistance
C	High, as compared to the circuit resistance
D	Approximately equal to inductive reactance

21. - E5B13

What letter is commonly used to represent susceptance?

Select	Answer
A	B
B	G
C	Y
D	X

22. - E5C04

Which of the following represents a capacitive reactance in polar coordinates?

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

23. - E5D16

What is the power factor of an R-L circuit having a 30 degree phase angle between the voltage and the current?

Select	Answer
A	0.5
B	0.577
C	0.866
D	1.73

24. - E6A06

What is the beta of a bipolar junction transistor?

Select	Answer
A	The switching speed of the transistor
B	The frequency at which the current gain is reduced to 1
C	The breakdown voltage of the base to collector junction
D	The change in collector current with respect to base current

25. - E6B08

Which of the following describes a type of semiconductor diode?

Select	Answer
A	Thermionic emission diode
B	Electrolytic rectifier
C	Metal-semiconductor junction
D	CMOS-field effect

26. - E6C14

What is the primary advantage of using a Programmable Gate Array (PGA) in a logic circuit?

Select	Answer
A	A PGA contains its own internal power supply
B	Complex logic functions can be created in a single integrated circuit
C	All of these choices are correct
D	Many similar gates are less expensive than a mixture of gate types

27. - E6D03

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

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

28. - E6E05

Which of the following noise figure values is typical of a low-noise UHF preamplifier?

Select	Answer
A	-20 dBm
B	-10 dB
C	2 dB
D	44 dBm

29. - E6F02

What happens to the conductivity of a photoconductive material when light shines on it?

Select	Answer
A	It stays the same
B	It becomes unstable
C	It increases
D	It decreases

30. - E7A05

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

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

31. - E7B15

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

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

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

33. - E7D04

Which of the following types of linear voltage regulator usually make the most efficient use of the primary power source?

Select	Answer
A	A series current source
B	A series regulator
C	A shunt current source
D	A shunt regulator

34. - E7E06

Why is de-emphasis commonly used in FM communications receivers?

Select	Answer
A	For compatibility with transmitters using phase modulation
B	To reduce impulse noise reception
C	For higher efficiency
D	To remove third-order distortion products

35. - E7F11

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

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

36. - E7G01

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

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

37. - E7H15

Which of these functions can be performed by a phase-locked loop?

Select	Answer
A	Wide-band AF and RF power amplification
B	Photovoltaic conversion, optical coupling
C	Comparison of two digital input signals, digital pulse counter
D	Frequency synthesis, FM demodulation

38. - E8A10

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

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

39. - E8B01

What is the term for the ratio between the frequency deviation of an RF carrier wave and the modulating frequency of its corresponding FM-phone signal?

Select	Answer
A	Modulation index
B	Quieting index
C	FM compressibility
D	Percentage of modulation

40. - E8C11

What is the relationship between symbol rate and baud?

Select	Answer
A	Baud is only used for RTTY
B	They are the same
C	Symbol rate is only used for packet-based modes
D	Baud is twice the symbol rate

41. - E8D04

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

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

42. - E9A07

What is meant by antenna gain?

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

43. - E9B07

How does the total amount of radiation emitted by a directional gain antenna compare with the total amount of radiation emitted from an isotropic antenna, assuming each is driven by the same amount of power?

Select	Answer
A	The total amount of radiation from the directional antenna is increased by the gain of the antenna
B	They are the same
C	The total amount of radiation from the directional antenna is stronger by its front-to-back ratio
D	The radiation from the isotropic antenna is 2.15 dB stronger than that from the directional antenna

44. - E9C01

What is the radiation pattern of two 1/4-wavelength vertical antennas spaced 1/2-wavelength apart and fed 180 degrees out of phase?

Select	Answer
A	A figure-8 broadside to the axis of the array
B	Cardioid
C	A figure-8 oriented along the axis of the array
D	Omni-directional

45. - E9D08

What happens as the Q of an antenna increases?

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

46. - E9E09

Which of these matching systems is an effective method of connecting a 50 ohm coaxial cable feed line to a grounded tower so it can be used as a vertical antenna?

Select	Answer
A	Double-bazooka match
B	Gamma match
C	Hairpin match
D	All of these choices are correct

47. - E9F01

What is the velocity factor of a transmission line?

Select	Answer
A	The ratio of the characteristic impedance of the line to the terminating impedance
B	The index of shielding for coaxial cable
C	The velocity of the wave in the transmission line multiplied by the velocity of light in a vacuum
D	The velocity of the wave in the transmission line divided by the velocity of light in a vacuum

48. - E9G11

How are the wavelength scales on a Smith chart calibrated?

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

49. - E9H09

Which of the following describes the construction of a receiving loop antenna?

Select	Answer
A	One or more turns of wire wound in the shape of a large open coil
B	A large circularly polarized antenna
C	A small coil of wire tightly wound around a toroidal ferrite core
D	A vertical antenna coupled to a feed line through an inductive loop of wire

50. - E0A10

What toxic material may be present in some electronic components such as high voltage capacitors and transformers?

Select	Answer
A	Polychlorinated Biphenyls
B	Polyethylene
C	Polytetrafluroethylene
D	Polymorphic silicon