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

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1. - E1A05

What is the maximum power output permitted on the 60 meter band?

Select	Answer
A	50 watts PEP effective radiated power relative to an isotropic radiator
B	100 watts PEP effective radiated power relative to an isotropic radiator
C	100 watts PEP effective radiated power relative to the gain of a half-wave dipole
D	50 watts PEP effective radiated power relative to a dipole

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	No special rules apply if your antenna structure will be less than 300 feet in height
D	You may have to notify the Federal Aviation Administration and register it with the FCC as required by Part 17 of FCC rules

3. - E1C08

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

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

4. - E1D11

Which amateur stations are eligible to operate as Earth stations?

Select	Answer
A	Any amateur station whose licensee has filed a pre-space notification with the FCC's International Bureau
B	Only those of Amateur Extra Class operators
C	Only those of General, Advanced or Amateur Extra Class operators
D	Any amateur station, subject to the privileges of the class of operator license held by the control operator

5. - E1E05

What is the minimum passing score on amateur operator license examinations?

Select	Answer
A	Minimum passing score of 70%
B	Minimum passing score of 77%
C	Minimum passing score of 74%
D	Minimum passing score of 80%

6. - E1F05

Amateur stations may not transmit in which of the following frequency segments if they are located in the contiguous 48 states and north of Line A?

Select	Answer
A	440 MHz - 450 MHz
B	53 MHz - 54 MHz
C	420 MHz - 430 MHz
D	222 MHz - 223 MHz

7. - E2A12

What is one way to predict the location of a satellite at a given time?

Select	Answer
A	By subtracting the mean anomaly from the orbital inclination
B	By means of the Doppler data for the specified satellite
C	By adding the mean anomaly to the orbital inclination
D	By calculations using the Keplerian elements for the specified satellite

8. - E2B06

What is vestigial sideband modulation?

Select	Answer
A	Amplitude modulation in which one complete sideband and a portion of the other are transmitted
B	A type of modulation in which one sideband is inverted
C	Spread spectrum modulation achieved by applying FM modulation following single sideband amplitude modulation
D	Narrow-band FM modulation achieved by filtering one sideband from the audio before frequency modulating the carrier

9. - E2C07

What is the Cabrillo format?

Select	Answer
A	A standard for submission of electronic contest logs
B	A method of exchanging information during a contest QSO
C	The most common set of contest rules
D	The rules of order for meetings between contest sponsors

10. - E2D11

Which of the following data are used by the APRS network to communicate your location?

Select	Answer
A	Time and frequency
B	Polar coordinates
C	Latitude and longitude
D	Radio direction finding spectrum analysis

11. - E2E13

Which of the following is a possible reason that attempts to initiate contact with a digital station on a clear frequency are unsuccessful?

Select	Answer
A	Your transmit frequency is incorrect
B	Another station you are unable to hear is using the frequency
C	The protocol version you are using is not the supported by the digital station
D	All of these choices are correct

12. - E3A06

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

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

13. - E3B03

What is the best time of day for transequatorial propagation?

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

14. - E3C15

What might a sudden rise in radio background noise indicate?

Select	Answer
A	A meteor ping
B	A solar flare has occurred
C	Long-path propagation is occurring
D	Increased transequatorial propagation likely

15. - E4A13

How is the compensation of an oscilloscope probe typically adjusted?

Select	Answer
A	A DC voltage standard is displayed and the probe is adjusted until the displayed voltage is accurate
B	A frequency standard is displayed and the probe is adjusted until the deflection time is accurate
C	A square wave is displayed and the probe is adjusted until the horizontal portions of the displayed wave are as nearly flat as possible
D	A high frequency sine wave is displayed and the probe is adjusted for maximum amplitude

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

17. - E4C11

Which of the following is a desirable amount of selectivity for an amateur SSB phone receiver?

Select	Answer
A	1 kHz
B	4.2 kHz
C	4.8 kHz
D	2.4 kHz

18. - E4D03

How can intermodulation interference between two repeaters occur?

Select	Answer
A	When the signals from the transmitters are reflected in phase from airplanes passing overhead
B	When the signals from the transmitters are reflected out of phase from airplanes passing overhead
C	When the repeaters are in close proximity and the signals cause feedback in the final amplifier of one or both transmitters
D	When the repeaters are in close proximity and the signals mix in the final amplifier of one or both transmitters

19. - E4E15

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

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

20. - E5A12

What is the half-power bandwidth of a parallel resonant circuit that has a resonant frequency of 3.7 MHz and a Q of 118?

Select	Answer
A	31.4 kHz
B	218.3 kHz
C	436.6 kHz
D	15.7 kHz

21. - E5B01

What is the term for the time required for the capacitor in an RC circuit to be charged to 63.2% of the applied voltage?

Select	Answer
A	An exponential rate of one
B	One exponential period
C	A time factor of one
D	One time constant

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 4
B	Point 6
C	Point 5
D	Point 2

23. - E5D10

How can the true power be determined in an AC circuit where the voltage and current are out of phase?

Select	Answer
A	By dividing the apparent power by the power factor
B	By dividing the reactive power by the power factor
C	By multiplying the apparent power times the power factor
D	By multiplying the reactive power times the power factor

24. - E6A15

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

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

25. - E6B09

What is a common use for point contact diodes?

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

26. - E6C04

What is the primary advantage of tri-state logic?

Select	Answer
A	Ability to connect many device outputs to a common bus
B	Low power consumption
C	More efficient arithmetic operations
D	High speed operation

27. - E6D16

What is the common name for a capacitor connected across a transformer secondary that is used to absorb transient voltage spikes?

Select	Answer
A	Clipper capacitor
B	Feedback capacitor
C	Trimmer capacitor
D	Snubber capacitor

28. - E6E09

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

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

29. - E6F04

What is the photovoltaic effect?

Select	Answer
A	The tendency of a battery to discharge when used outside
B	The conversion of voltage to current when exposed to light
C	The conversion of light to electrical energy
D	The conversion of electrical energy to mechanical energy

30. - E7A01

Which is a bi-stable circuit?

Select	Answer
A	An "AND" gate
B	A clock
C	A flip-flop
D	An "OR" gate

31. - E7B14

Why are switching amplifiers more efficient than linear amplifiers?

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

32. - E7C06

What are the distinguishing features of an elliptical filter?

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

33. - E7D07

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

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

34. - E7E07

What is meant by the term baseband in radio communications?

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

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	Higher data rate
C	Complex phasor representations
D	More taps

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 decreases logarithmically with increasing frequency
C	It increases linearly with increasing frequency
D	It does not vary with frequency

37. - E7H04

How is positive feedback supplied in a Colpitts oscillator?

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

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	Improve accuracy by removing out of sequence codes from the input
C	Lower the input bandwidth to increase the effective resolution
D	Remove harmonics from the output caused by the discrete analog levels generated

39. - E8B04

What is the modulation index of an FM-phone signal having a maximum carrier deviation of plus or minus 6 kHz when modulated with a 2 kHz modulating frequency?

Select	Answer
A	2000
B	3
C	6000
D	1/3

40. - E8C03

When performing phase shift keying, why is it advantageous to shift phase precisely at the zero crossing of the RF carrier?

Select	Answer
A	It is easier to demodulate with a conventional, non-synchronous detector
B	This results in the least possible transmitted bandwidth for the particular mode
C	It improves carrier suppression
D	All of these choices are correct

41. - E8D04

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

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

42. - E9A09

How is antenna efficiency calculated?

Select	Answer
A	(effective radiated power / transmitter output) x 100 percent
B	(total resistance / radiation resistance) x 100 per cent
C	(radiation resistance / total resistance) x 100 per cent
D	(radiation resistance / transmission resistance) x 100 per cent

43. - E9B15

What is the front-to-back ratio of the radiation pattern shown in Figure E9-2?

Select	Answer
A	15 dB
B	28 dB
C	3 dB
D	24 dB

44. - E9C09

What is a G5RV antenna?

Select	Answer
A	A multi-band dipole antenna fed with coax and a balun through a selected length of open wire transmission line
B	A phased array antenna consisting of multiple loops
C	A multi-band trap antenna
D	A wide band dipole using shorted coaxial cable for the radiating elements and fed with a 4:1 balun

45. - E9D07

What is an advantage of using top loading in a shortened HF vertical antenna?

Select	Answer
A	Greater structural strength
B	Lower Q
C	Improved radiation efficiency
D	Higher losses

46. - E9E04

What is the purpose of the series capacitor in a gamma-type antenna matching network?

Select	Answer
A	To provide DC isolation between the feed line and the antenna
B	To provide a rejection notch that prevents the radiation of harmonics
C	To transform the antenna impedance to a higher value
D	To cancel the inductive reactance of the matching network

47. - E9F10

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

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

48. - E9G04

What are the two families of circles and arcs that make up a Smith chart?

Select	Answer
A	Resistance and reactance
B	Reactance and voltage
C	Resistance and voltage
D	Voltage and impedance

49. - E9H10

How can the output voltage of a multiple turn receiving loop antenna be increased?

Select	Answer
A	By winding adjacent turns in opposing directions
B	By increasing either the number of wire turns in the loop or the area of the loop structure or both
C	By reducing the permeability of the loop shield
D	By increasing the number of wire turns in the loop and reducing the area of the loop structure

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	All of these choices are correct
D	Ground reflections and scattering make the field impedance vary with location

Figure E5-2

Figure E7-3

Figure E9-2