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

2. - E1B07

What is the highest modulation index permitted at the highest modulation frequency for angle modulation below 29.0 MHz?

Select	Answer
A	2.0
B	1.0
C	3.0
D	0.5

3. - E1C12

What types of communications may be transmitted to amateur stations in foreign countries?

Select	Answer
A	All of these choices are correct
B	Messages intended for connection to users of the maritime satellite service
C	Business-related messages for non-profit organizations
D	Communications incidental to the purpose of the amateur service and remarks of a personal nature

4. - E1D10

Which amateur stations are eligible to be telecommand stations?

Select	Answer
A	Any amateur station so designated by the space station licensee, subject to the privileges of the class of operator license held by the control operator
B	Any amateur station so designated by the ITU
C	All of these choices are correct
D	Any amateur station designated by NASA

5. - E1E08

To which of the following examinees may a VE not administer an examination?

Select	Answer
A	All of these choices are correct
B	Relatives of the VE as listed in the FCC rules
C	Employees of the VE
D	Friends of the VE

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 additional spectrum for personal use
C	To provide for experimental amateur communications
D	To allow regular operation on Land Mobile channels

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	435 MHz - 438 MHz
C	144 MHz - 146 MHz
D	50.0 MHz - 50.2 MHz

8. - E2B19

What special operating frequency restrictions are imposed on slow scan TV transmissions?

Select	Answer
A	None; they are allowed on all amateur frequencies
B	They are restricted to 7.245 MHz, 14.245 MHz, 21.345 MHz, and 28.945 MHz
C	They are restricted to phone band segments and their bandwidth can be no greater than that of a voice signal of the same modulation type
D	They are not permitted above 54 MHz

9. - E2C05

What is the function of a DX QSL Manager?

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

10. - E2D01

Which of the following digital modes is especially designed for use for meteor scatter signals?

Select	Answer
A	Hellschreiber
B	FSK441
C	WSPR
D	APRS

11. - E2E11

What is the difference between direct FSK and audio FSK?

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

12. - E3A06

Which of the following is required for microwave propagation via rain scatter?

Select	Answer
A	Rain droplets must be within the E layer
B	Rain droplets must be electrically charged
C	All of these choices are correct
D	The rain must be within radio range of both stations

13. - E3B01

What is transequatorial propagation?

Select	Answer
A	Propagation between two continents by way of ducts along the magnetic equator
B	Propagation between two stations at the same latitude
C	Propagation between two mid-latitude points at approximately the same distance north and south of the magnetic equator
D	Propagation between any two points located on the magnetic equator

14. - E3C07

Which of the following descriptors indicates the greatest solar flare intensity?

Select	Answer
A	Class X
B	Class B
C	Class A
D	Class M

15. - E4A11

Which of the following is good practice when using an oscilloscope probe?

Select	Answer
A	All of these choices are correct
B	Keep the signal ground connection of the probe as short as possible
C	Never use a high impedance probe to measure a low impedance circuit
D	Never use a DC-coupled probe to measure an AC circuit

16. - E4B05

If a frequency counter with a specified accuracy of +/- 10 ppm reads 146,520,000 Hz, what is the most the actual frequency being measured could differ from the reading?

Select	Answer
A	10 Hz
B	1465.20 Hz
C	146.52 kHz
D	146.52 Hz

17. - E4C02

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

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

18. - E4D13

Which of the following can cause receiver desensitization?

Select	Answer
A	Audio gain adjusted too low
B	Strong adjacent channel signals
C	Squelch gain misadjusted
D	Audio bias adjusted too high

19. - E4E01

Which of the following types of receiver noise can often be reduced by use of a receiver noise blanker?

Select	Answer
A	All of these choices are correct
B	Heterodyne interference
C	Ignition noise
D	Broadband white noise

20. - E5A08

What is the phase relationship between the current through and the voltage across a series resonant circuit at resonance?

Select	Answer
A	The current leads the voltage by 90 degrees
B	The voltage leads the current by 90 degrees
C	The voltage and current are in phase
D	The voltage and current are 180 degrees out of phase

21. - E5B03

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

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

22. - E5C06

What does the impedance 50-j25 represent?

Select	Answer
A	25 ohms resistance in series with 50 ohms capacitive reactance
B	25 ohms resistance in series with 50 ohms inductive reactance
C	50 ohms resistance in series with 25 ohms inductive reactance
D	50 ohms resistance in series with 25 ohms capacitive reactance

23. - E5D14

What is reactive power?

Select	Answer
A	Wattless, nonproductive power
B	Power consumed in wire resistance in an inductor
C	Power consumed in circuit Q
D	Power lost because of capacitor leakage

24. - E6A06

What is the beta of a bipolar junction transistor?

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

25. - E6B05

What characteristic of a PIN diode makes it useful as an RF switch or attenuator?

Select	Answer
A	Ability to dissipate large amounts of power
B	A large region of intrinsic material
C	Extremely high reverse breakdown voltage
D	Reverse bias controls its forward voltage drop

26. - E6C06

Why do CMOS digital integrated circuits have high immunity to noise on the input signal or power supply?

Select	Answer
A	Input signals are stronger
B	The input switching threshold is about two times the power supply voltage
C	The input switching threshold is about one-half the power supply voltage
D	Larger bypass capacitors are used in CMOS circuit design

27. - E6D13

What is the primary cause of inductor self-resonance?

Select	Answer
A	Inter-turn capacitance
B	Inductive kickback
C	Non-linear core hysteresis
D	The skin effect

28. - E6E09

Which of the following component package types would be most suitable for use at frequencies above the HF range?

Select	Answer
A	TO-220
B	Surface mount
C	Radial lead
D	Axial lead

29. - E6F14

Which of the following is true of LCD displays?

Select	Answer
A	They may be hard view through polarized lenses
B	They are hard to view in high ambient light conditions
C	All of these choices are correct
D	They only display alphanumeric symbols

30. - E7A09

What logical operation is performed by an exclusive NOR gate?

Select	Answer
A	It produces logic "0" at its output if any single input is logic "1"
B	It produces logic "1" at its output if any single input is logic "1"
C	It produces logic "0" at its output only if all inputs are logic "0"
D	It produces logic "1" at its output only if all inputs are logic "1"

31. - E7B10

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

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

32. - E7C11

Which of the following is the common name for a filter network which is equivalent to two L-networks connected back-to-back with the two inductors in series and the capacitors in shunt at the input and output?

Select	Answer
A	Pi-L
B	Omega
C	Cascode
D	Pi

33. - E7D02

What is one characteristic of a switching electronic voltage regulator?

Select	Answer
A	The controlled device's duty cycle is changed to produce a constant average output voltage
B	It is generally less efficient than a linear regulator
C	It gives a ramp voltage at its output
D	The resistance of a control element is varied in direct proportion to the line voltage or load current

34. - E7E07

What is meant by the term baseband in radio communications?

Select	Answer
A	The unmodulated bandwidth of the transmitted signal
B	The basic oscillator frequency in an FM transmitter that is multiplied to increase the deviation and carrier frequency
C	The frequency components present in the modulating signal
D	The lowest frequency band that the transmitter or receiver covers

35. - E7F01

What is meant by direct digital conversion as applied to software defined radios?

Select	Answer
A	Software is converted from source code to object code during operation of the receiver
B	Incoming RF is digitized by an analog-to-digital converter without being mixed with a local oscillator signal
C	Incoming RF is converted to a control voltage for a voltage controlled oscillator
D	A switching mixer is used to generate I and Q signals directly from the RF input

36. - E7G06

Which of the following is the most appropriate use of an op-amp active filter?

Select	Answer
A	As a high-pass filter used to block RFI at the input to receivers
B	For smoothing power supply output
C	As a low-pass filter used between a transmitter and a transmission line
D	As an audio filter in a receiver

37. - E7H03

How is positive feedback supplied in a Hartley oscillator?

Select	Answer
A	Through link coupling
B	Through a neutralizing capacitor
C	Through a tapped coil
D	Through a capacitive divider

38. - E8A06

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

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

39. - E8B11

What is digital time division multiplexing?

Select	Answer
A	Two or more data streams share the same channel by transmitting time of transmission as the sub-carrier
B	Two or more signals are arranged to share discrete time slots of a data transmission
C	Two or more signals are quadrature modulated to increase bandwidth efficiency
D	Two or more data streams are assigned to discrete sub-carriers on an FM transmitter

40. - E8C04

What technique is used to minimize the bandwidth requirements of a PSK31 signal?

Select	Answer
A	Zero-sum character encoding
B	Use of trapezoidal data pulses
C	Use of sinusoidal data pulses
D	Reed-Solomon character encoding

41. - E8D07

What is a common cause of overmodulation of AFSK signals?

Select	Answer
A	Ground loops
B	Excessive transmit audio levels
C	Bit errors in the modem
D	Excessive numbers of retries

42. - E9A10

Which of the following choices is a way to improve the efficiency of a ground-mounted quarter-wave vertical antenna?

Select	Answer
A	Reduce the diameter of the radiating element
B	Install a good radial system
C	Isolate the coax shield from ground
D	Shorten the radiating element

43. - E9B09

What type of computer program technique is commonly used for modeling antennas?

Select	Answer
A	Graphical analysis
B	Method of Moments
C	Mutual impedance analysis
D	Calculus differentiation with respect to physical properties

44. - E9C07

What is the approximate feed point impedance at the center of a two-wire folded dipole antenna?

Select	Answer
A	450 ohms
B	72 ohms
C	300 ohms
D	50 ohms

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 increases
D	SWR bandwidth decreases

46. - E9E03

What is the name of the matching system that uses a section of transmission line connected in parallel with the feed line at or near the feed point?

Select	Answer
A	The delta match
B	The gamma match
C	The omega match
D	The stub match

47. - E9F12

What impedance does a 1/4 wavelength transmission line present to a generator when the line is open at the far end?

Select	Answer
A	The same as the input impedance to the generator
B	Very low impedance
C	The same as the characteristic impedance of the line
D	Very high impedance

48. - E9G05

What type of chart is shown in Figure E9-3?

Select	Answer
A	Elevation angle radiation pattern chart
B	Azimuth angle radiation pattern chart
C	Free space radiation directivity chart
D	Smith chart

49. - E9H11

What characteristic of a cardioid pattern antenna is useful for direction finding?

Select	Answer
A	Broad band response
B	A very sharp peak
C	A very sharp single null
D	High-radiation angle

50. - E0A06

Why are there separate electric (E) and magnetic (H) field MPE limits?

Select	Answer
A	E field and H field radiation intensity peaks can occur at different locations
B	The body reacts to electromagnetic radiation from both the E and H fields
C	Ground reflections and scattering make the field impedance vary with location
D	All of these choices are correct

Figure E7-1

Figure E9-3