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

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1. - E1A14

What is the maximum bandwidth for a data emission on 60 meters?

Select	Answer
A	1.5 kHz
B	170 Hz
C	60 Hz
D	2.8 kHz

2. - E1B09

Which amateur stations may be operated under RACES rules?

Select	Answer
A	Only those club stations licensed to Amateur Extra class operators
B	Any FCC-licensed amateur station except a Technician class
C	Any FCC-licensed amateur station certified by the responsible civil defense organization for the area served
D	Any FCC-licensed amateur station participating in the Military Auxiliary Radio System (MARS)

3. - E1C09

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

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

4. - E1D01

What is the definition of the term telemetry?

Select	Answer
A	Two-way single channel transmissions of data
B	Two-way radiotelephone transmissions in excess of 1000 feet
C	One-way transmission of measurements at a distance from the measuring instrument
D	One-way transmission that initiates, modifies, or terminates the functions of a device at a distance

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

6. - E1F04

Which of the following geographic descriptions approximately describes "Line A"?

Select	Answer
A	A line roughly parallel to and north of the U.S.-Mexican border and Gulf coastline
B	A line roughly parallel to and east of the U.S. Pacific coastline
C	A line roughly parallel to and south of the U.S.-Canadian border
D	A line roughly parallel to and west of the U.S. Atlantic coastline

7. - E2A05

What do the letters in a satellite's mode designator specify?

Select	Answer
A	The location of the ground control station
B	The polarization of uplink and downlink signals
C	Power limits for uplink and downlink transmissions
D	The uplink and downlink frequency ranges

8. - E2B18

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

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

9. - E2C13

What indicator is required to be used by U.S.-licensed operators when operating a station via remote control where the transmitter is located in the U.S.?

Select	Answer
A	/ followed by the USPS two letter abbreviation for the state in which the remote station is located
B	/R# where # is the district of the remote station
C	The ARRL section of the remote station
D	No additional indicator is required

10. - E2D07

What digital protocol is used by APRS?

Select	Answer
A	PACTOR
B	802.11
C	AMTOR
D	AX.25

11. - E2E10

Which of these digital modes has the narrowest bandwidth?

Select	Answer
A	300-baud packet
B	MFSK16
C	PSK31
D	170 Hz shift, 45 baud RTTY

12. - E3A14

From the contiguous 48 states, in which approximate direction should an antenna be pointed to take maximum advantage of aurora propagation?

Select	Answer
A	North
B	East
C	South
D	West

13. - E3B02

What is the approximate maximum range for signals using transequatorial propagation?

Select	Answer
A	1000 miles
B	7500 miles
C	2500 miles
D	5000 miles

14. - E3C01

What does the term ray tracing describe in regard to radio communications?

Select	Answer
A	The process in which an electronic display presents a pattern
B	Determining the radiation pattern from an array of antennas
C	Modeling a radio wave's path through the ionosphere
D	Evaluating high voltage sources for X-Rays

15. - E4A13

How is the compensation of an oscilloscope probe typically adjusted?

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

16. - E4B02

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

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

17. - E4C08

An SDR receiver is overloaded when input signals exceed what level?

Select	Answer
A	One-half the maximum sample rate
B	The maximum count value of the analog-to-digital converter
C	The reference voltage of the analog-to-digital converter
D	One-half the maximum sampling buffer size

18. - E4D06

What is the term for unwanted signals generated by the mixing of two or more signals?

Select	Answer
A	Amplifier desensitization
B	Adjacent channel interference
C	Intermodulation interference
D	Neutralization

19. - E4E02

Which of the following types of receiver noise can often be reduced with a DSP noise filter?

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

20. - E5A05

What is the magnitude of the current at the input of a series RLC circuit as the frequency goes through resonance?

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

21. - E5B13

What letter is commonly used to represent susceptance?

Select	Answer
A	X
B	Y
C	G
D	B

22. - E5C05

What is the name of the diagram used to show the phase relationship between impedances at a given frequency?

Select	Answer
A	Venn diagram
B	Near field diagram
C	Phasor diagram
D	Far field diagram

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

24. - E6A01

In what application is gallium arsenide used as a semiconductor material in preference to germanium or silicon?

Select	Answer
A	In high-current rectifier circuits
B	In microwave circuits
C	In high-power audio circuits
D	In very low frequency RF circuits

25. - E6B07

What is the failure mechanism when a junction diode fails due to excessive current?

Select	Answer
A	Excessive junction temperature
B	Charge carrier depletion
C	Insufficient forward voltage
D	Excessive inverse voltage

26. - E6C05

What is an advantage of CMOS logic devices over TTL devices?

Select	Answer
A	Lower power consumption
B	Differential output capability
C	Immune to damage from static discharge
D	Lower distortion

27. - E6D06

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

Select	Answer
A	Permeability
B	Resistance
C	Thermal impedance
D	Reactivity

28. - E6E05

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

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

29. - E6F09

What is the efficiency of a photovoltaic cell?

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

30. - E7A08

What logical operation does an OR gate perform?

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

31. - E7B08

How can an RF power amplifier be neutralized?

Select	Answer
A	By feeding a 180-degree out-of-phase portion of the output back to the input
B	By reducing the driving power
C	By feeding an in-phase component of the output back to the input
D	By increasing the driving power

32. - E7C03

What advantage does a Pi-L-network have over a regular Pi-network for impedance matching between the final amplifier of a vacuum-tube transmitter and an antenna?

Select	Answer
A	Lower losses
B	Higher efficiency
C	Greater transformation range
D	Greater harmonic suppression

33. - E7D01

What is one characteristic of a linear electronic voltage regulator?

Select	Answer
A	It has a ramp voltage as its output
B	The conduction of a control element is varied to maintain a constant output voltage
C	The control element duty cycle is proportional to the line or load conditions
D	It eliminates the need for a pass transistor

34. - E7E02

What is the function of a reactance modulator?

Select	Answer
A	To produce PM signals by using an electrically variable resistance
B	To produce PM signals by using an electrically variable inductance or capacitance
C	To produce AM signals by using an electrically variable inductance or capacitance
D	To produce AM signals by using an electrically variable resistance

35. - E7F11

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

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

36. - E7G09

What will be the output voltage of the circuit shown in Figure E7-4 if R1 is 1000 ohms, RF is 10,000 ohms, and 0.23 volts DC is applied to the input?

Select	Answer
A	-0.23 volts
B	-2.3 volts
C	0.23 volts
D	2.3 volts

37. - E7H03

How is positive feedback supplied in a Hartley oscillator?

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

38. - E8A08

Why would a direct or flash conversion analog-to-digital converter be useful for a software defined radio?

Select	Answer
A	Immunity to out of sequence coding reduces spurious responses
B	All of these choices are correct
C	Very low power consumption decreases frequency drift
D	Very high speed allows digitizing high frequencies

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	FM compressibility
C	Percentage of modulation
D	Quieting index

40. - E8C05

What is the necessary bandwidth of a 13-WPM international Morse code transmission?

Select	Answer
A	Approximately 104 Hz
B	Approximately 26 Hz
C	Approximately 52 Hz
D	Approximately 13 Hz

41. - E8D12

What is the advantage of including a parity bit with an ASCII character stream?

Select	Answer
A	The signal can overpower interfering signals
B	Faster transmission rate
C	Some types of errors can be detected SUBELEMENT E9 - ANTENNAS AND TRANSMISSION LINES [8 Exam Questions - 8 Groups] E9A Basic Antenna parameters: radiation resistance, gain, beamwidth, efficiency, beamwidth; effective radiated power, polarization E9A01 (C) What describes an isotropic antenna? A. A grounded antenna used to measure earth conductivity B. A horizontally polarized antenna used to compare Yagi antennas C. A theoretical antenna used as a reference for antenna gain D. A spacecraft antenna used to direct signals toward the earth
D	Foreign language characters can be sent

42. - E9A03

Why would one need to know the feed point impedance of an antenna?

Select	Answer
A	To calculate the front-to-back ratio of the antenna
B	To match impedances in order to minimize standing wave ratio on the transmission line
C	To measure the near-field radiation density from a transmitting antenna
D	To calculate the front-to-side ratio of the antenna

43. - E9B02

In the antenna radiation pattern shown in Figure E9-1, what is the front-to-back ratio?

Select	Answer
A	36 dB
B	24 dB
C	18 dB
D	14 dB

44. - E9C02

What is the radiation pattern of two 1/4 wavelength vertical antennas spaced 1/4 wavelength apart and fed 90 degrees out of phase?

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

45. - E9D13

What usually occurs if a Yagi antenna is designed solely for maximum forward gain?

Select	Answer
A	The front-to-back ratio increases
B	The frequency response is widened over the whole frequency band
C	The front-to-back ratio decreases
D	The SWR is reduced

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

47. - E9F08

What is the term for the ratio of the actual speed at which a signal travels through a transmission line to the speed of light in a vacuum?

Select	Answer
A	Velocity factor
B	Standing wave ratio
C	Surge impedance
D	Characteristic impedance

48. - E9G05

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

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

49. - E9H06

What is the triangulation method of direction finding?

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

50. - E0A07

How may dangerous levels of carbon monoxide from an emergency generator be detected?

Select	Answer
A	Only with a carbon monoxide detector
B	Any ordinary smoke detector can be used
C	By the odor
D	By the yellowish appearance of the gas

Figure E7-4

Figure E9-1

Figure E9-3