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

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1. - E1A11

Which of the following describes authorization or licensing required when operating an amateur station aboard a U.S.-registered vessel in international waters?

Select	Answer
A	Only General class or higher amateur licenses
B	An unrestricted Radiotelephone Operator Permit
C	Any amateur license with an FCC Marine or Aircraft endorsement
D	Any FCC-issued amateur license

2. - E1B01

Which of the following constitutes a spurious emission?

Select	Answer
A	Any transmitted signal that unintentionally interferes with another licensed radio station
B	A signal transmitted to prevent its detection by any station other than the intended recipient
C	An amateur station transmission made at random without the proper call sign identification
D	An emission outside its necessary bandwidth that can be reduced or eliminated without affecting the information transmitted

3. - E1C08

What is the maximum permissible duration of a remotely controlled station's transmissions if its control link malfunctions?

Select	Answer
A	10 minutes
B	3 minutes
C	5 minutes
D	30 seconds

4. - E1D07

Which amateur service HF bands have frequencies authorized for space stations?

Select	Answer
A	Only the 40 m, 20 m, 17 m, 15 m and 10 m bands
B	Only the 40 m, 20 m, 17 m, 15 m, 12 m and 10 m bands
C	All HF bands
D	Only the 40 m, 30 m, 20 m, 15 m, 12 m and 10 m bands

5. - E1E12

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

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

6. - E1F09

Which of the following conditions apply when transmitting spread spectrum emission?

Select	Answer
A	All of these choices are correct
B	A station transmitting SS emission must not cause harmful interference to other stations employing other authorized emissions
C	The transmission must not be used to obscure the meaning of any communication
D	The transmitting station must be in an area regulated by the FCC or in a country that permits SS emissions

7. - E2A02

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

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

8. - E2B16

Which is a video standard used by North American Fast Scan ATV stations?

Select	Answer
A	PAL
B	DRM
C	Scottie
D	NTSC

9. - E2C03

From which of the following bands is amateur radio contesting generally excluded?

Select	Answer
A	33 cm
B	6 m
C	2 m
D	30 m

10. - E2D12

How does JT65 improve EME communications?

Select	Answer
A	It controls the receiver to track Doppler shift
B	It can decode signals many dB below the noise floor using FEC
C	All of these choices are correct
D	It supplies signals to guide the antenna to track the Moon

11. - E2E09

Which of the following HF digital modes uses variable-length coding for bandwidth efficiency?

Select	Answer
A	MT63
B	PSK31
C	RTTY
D	PACTOR

12. - E3A08

When a meteor strikes the Earth's atmosphere, a cylindrical region of free electrons is formed at what layer of the ionosphere?

Select	Answer
A	The F2 layer
B	The E layer
C	The F1 layer
D	The D layer

13. - E3B13

Why is chordal hop propagation desirable?

Select	Answer
A	Signals travel faster along ionospheric chords
B	Atmospheric noise is lower in the direction of chordal hop propagation
C	The MUF for chordal hop propagation is much lower than for normal skip propagation
D	The signal experiences less loss along the path compared to normal skip propagation

14. - E3C11

What does VOACAP software model?

Select	Answer
A	HF propagation
B	VHF radio propagation
C	AC voltage and impedance
D	AC current and impedance

15. - E4A15

What is an advantage of a period-measuring frequency counter over a direct-count type?

Select	Answer
A	It provides improved resolution of low-frequency signals within a comparable time period
B	It does not require an expensive high-precision time base
C	It can run on battery power for remote measurements
D	It can directly measure the modulation index of an FM transmitter

16. - E4B10

Which of the following describes a method to measure intermodulation distortion in an SSB transmitter?

Select	Answer
A	Modulate the transmitter with two harmonically related audio frequencies and observe the RF output with a peak reading wattmeter
B	Modulate the transmitter with two non-harmonically related radio frequencies and observe the RF output with a spectrum analyzer
C	Modulate the transmitter with two non-harmonically related audio frequencies and observe the RF output with a spectrum analyzer
D	Modulate the transmitter with two harmonically related audio frequencies and observe the RF output with a logic analyzer

17. - E4C12

What is an undesirable effect of using too wide a filter bandwidth in the IF section of a receiver?

Select	Answer
A	Undesired signals may be heard
B	Thermal-noise distortion
C	Filter ringing
D	Output-offset overshoot

18. - E4D02

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

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

19. - E4E15

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

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

20. - E5A07

What is the magnitude of the current at the input of a parallel RLC circuit at resonance?

Select	Answer
A	Maximum
B	Minimum
C	L/R
D	R/L

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	220 seconds
B	110 seconds
C	440 seconds
D	55 seconds

22. - E5C11

What do the two numbers that are used to define a point on a graph using rectangular coordinates represent?

Select	Answer
A	The tangent and cotangent values
B	The sine and cosine values
C	The coordinate values along the horizontal and vertical axes
D	The magnitude and phase of the point

23. - E5D11

What is the power factor of an R-L circuit having a 60 degree phase angle between the voltage and the current?

Select	Answer
A	0.866
B	1.73
C	0.5
D	1.414

24. - E6A06

What is the beta of a bipolar junction transistor?

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

25. - E6B11

What is used to control the attenuation of RF signals by a PIN diode?

Select	Answer
A	Capacitance of an RF coupling capacitor
B	Forward DC bias current
C	Reverse voltage larger than the RF signal
D	A sub-harmonic pump signal

26. - E6C13

Which of the following is an advantage of BiCMOS logic?

Select	Answer
A	It is totally immune to electrostatic damage
B	It has the high input impedance of CMOS and the low output impedance of bipolar transistors
C	Its simplicity results in much less expensive devices than standard CMOS
D	All of these choices are correct

27. - E6D13

What is the primary cause of inductor self-resonance?

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

28. - E6E02

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

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

29. - E6F09

What is the efficiency of a photovoltaic cell?

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

30. - E7A04

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

Select	Answer
A	4
B	2
C	1
D	8

31. - E7B03

Which of the following components form the output of a class D amplifier circuit?

Select	Answer
A	A low-pass filter to remove switching signal components
B	A temperature compensating load resistor to improve linearity
C	A matched load resistor to prevent damage by switching transients
D	A high-pass filter to compensate for low gain at low frequencies

32. - E7C06

What are the distinguishing features of an elliptical filter?

Select	Answer
A	Extremely flat response over its pass band with gradually rounded stop band corners
B	Gradual passband rolloff with minimal stop band ripple
C	Extremely sharp cutoff with one or more notches in the stop band
D	Gradual passband rolloff with extreme stop band ripple

33. - E7D02

What is one characteristic of a switching electronic voltage regulator?

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

34. - E7E07

What is meant by the term baseband in radio communications?

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

35. - E7F06

What is the minimum number of bits required for an analog-to-digital converter to sample a signal with a range of 1 volt at a resolution of 1 millivolt?

Select	Answer
A	6 bits
B	8 bits
C	4 bits
D	10 bits

36. - E7G08

How does the gain of an ideal operational amplifier vary with frequency?

Select	Answer
A	It decreases linearly with increasing frequency
B	It does not vary with frequency
C	It increases linearly with increasing frequency
D	It decreases logarithmically with increasing frequency

37. - E7H13

Which of the following is a technique for providing highly accurate and stable oscillators needed for microwave transmission and reception?

Select	Answer
A	Use a temperature-controlled high Q dielectric resonator
B	Use a GPS signal reference
C	All of these choices are correct
D	Use a rubidium stabilized reference oscillator

38. - E8A02

What type of wave has a rise time significantly faster than its fall time (or vice versa)?

Select	Answer
A	A square wave
B	A sawtooth wave
C	A sine wave
D	A cosine wave

39. - E8B09

What is meant by deviation ratio?

Select	Answer
A	The ratio of the maximum carrier frequency deviation to the highest audio modulating frequency
B	The ratio of the audio modulating frequency to the center carrier frequency
C	The ratio of the carrier center frequency to the audio modulating frequency
D	The ratio of the highest audio modulating frequency to the average audio modulating frequency

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 sinusoidal data pulses
C	Use of trapezoidal data pulses
D	Reed-Solomon character encoding

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

42. - E9A05

What is included in the total resistance of an antenna system?

Select	Answer
A	Radiation resistance plus transmission resistance
B	Radiation resistance plus ohmic resistance
C	Transmission-line resistance plus radiation resistance
D	Radiation resistance plus space impedance

43. - E9B08

How can the approximate beam-width in a given plane of a directional antenna be determined?

Select	Answer
A	Measure the ratio of the signal strengths of the radiated power lobes from the front and side of the antenna
B	Draw two imaginary lines through the ends of the elements and measure the angle between the lines
C	Measure the ratio of the signal strengths of the radiated power lobes from the front and rear of the antenna
D	Note the two points where the signal strength of the antenna is 3 dB less than maximum and compute the angular difference

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	50 ohms
C	300 ohms
D	72 ohms

45. - E9D01

How does the gain of an ideal parabolic dish antenna change when the operating frequency is doubled?

Select	Answer
A	Gain does not change
B	Gain increases by 6 dB
C	Gain is multiplied by 0.707
D	Gain increases by 3 dB

46. - E9E06

What is the equivalent lumped-constant network for a hairpin matching system of a 3-element Yagi?

Select	Answer
A	A series capacitor
B	A shunt inductor
C	Pi-network
D	Pi-L-network

47. - E9F14

What impedance does a 1/2 wavelength transmission line present to a generator when the line is shorted at the far end?

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

48. - E9G05

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

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

49. - E9H04

What is an advantage of using a shielded loop antenna for direction finding?

Select	Answer
A	It automatically cancels ignition noise in mobile installations
B	It eliminates tracking errors caused by strong out-of-band signals
C	It is electro statically balanced against ground, giving better nulls
D	It allows stations to communicate without giving away their position

50. - E0A04

When evaluating a site with multiple transmitters operating at the same time, the operators and licensees of which transmitters are responsible for mitigating over-exposure situations?

Select	Answer
A	Each transmitter operating with a duty-cycle greater than 50 percent
B	Only commercial transmitters
C	Each transmitter that produces 5 percent or more of its MPE limit at accessible locations
D	Only the most powerful transmitter

Figure E9-3