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

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1. - E1A06

Where must the carrier frequency of a CW signal be set to comply with FCC rules for 60 meter operation?

Select	Answer
A	On any frequency where the signal's sidebands are within the channel
B	At the highest frequency of the channel
C	At the lowest frequency of the channel
D	At the center frequency of the channel

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. - E1C07

What is meant by local control?

Select	Answer
A	Direct manipulation of the transmitter by a control operator
B	Controlling a station through a local auxiliary link
C	Automatically manipulating local station controls
D	Controlling a repeater using a portable handheld transceiver

4. - E1D06

Which of the following is a requirement of a space station?

Select	Answer
A	The space station must be capable of terminating transmissions by telecommand when directed by the FCC
B	The space station must be capable of changing its orbit whenever such a change is ordered by NASA
C	The space station must cease all transmissions after 5 years
D	All of these choices are correct

5. - E1E02

Where are the questions for all written U.S. amateur license examinations listed?

Select	Answer
A	In a question pool maintained by all the VECs
B	In a question pool maintained by the FCC
C	In the appropriate FCC Report and Order
D	In FCC Part 97

6. - E1F09

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

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

7. - E2A01

What is the direction of an ascending pass for an amateur satellite?

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

8. - E2B02

How many horizontal lines make up a fast-scan (NTSC) television frame?

Select	Answer
A	525
B	1080
C	30
D	60

9. - E2C05

What is the function of a DX QSL Manager?

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

10. - E2D14

What is one advantage of using JT65 coding?

Select	Answer
A	The ability to decode signals which have a very low signal to noise ratio
B	Easily copied by ear if necessary
C	Uses only a 65 Hz bandwidth
D	Permits fast-scan TV transmissions over narrow bandwidth

11. - E2E04

What is indicated when one of the ellipses in an FSK crossed-ellipse display suddenly disappears?

Select	Answer
A	One of the signal filters is saturated
B	The mark and space signal have been inverted
C	The receiver has drifted 5 kHz from the desired receive frequency
D	Selective fading has occurred

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	East
B	South
C	West
D	North

13. - E3B07

Which of the following could account for hearing an echo on the received signal of a distant station?

Select	Answer
A	Meteor scatter
B	Receipt of a signal by more than one path
C	Transmit frequency is higher than the MUF
D	High D layer absorption

14. - E3C02

What is indicated by a rising A or K index?

Select	Answer
A	Higher levels of solar UV radiation
B	An increase in the critical frequency
C	Increasing disruption of the geomagnetic field
D	Decreasing disruption of the geomagnetic field

15. - E4A02

Which of the following parameters would a spectrum analyzer display on the vertical and horizontal axes?

Select	Answer
A	SWR and frequency
B	SWR and time
C	RF amplitude and frequency
D	RF amplitude and time

16. - E4B13

Which S parameter is equivalent to forward gain?

Select	Answer
A	S22
B	S21
C	S11
D	S12

17. - E4C14

What transmit frequency might generate an image response signal in a receiver tuned to 14.300 MHz and which uses a 455 kHz IF frequency?

Select	Answer
A	15.210 MHz
B	14.755 MHz
C	14.445 MHz
D	13.845 MHz

18. - E4D14

Which of the following is a way to reduce the likelihood of receiver desensitization?

Select	Answer
A	Decrease the RF bandwidth of the receiver
B	Raise the receiver IF frequency
C	Switch from fast AGC to slow AGC
D	Increase the receiver front end gain

19. - E4E04

How can conducted and radiated noise caused by an automobile alternator be suppressed?

Select	Answer
A	By installing filter capacitors in series with the DC power lead and a blocking capacitor in the field lead
B	By installing a noise suppression resistor and a blocking capacitor in both leads
C	By installing a high-pass filter in series with the radio's power lead and a low-pass filter in parallel with the field lead
D	By connecting the radio's power leads directly to the battery and by installing coaxial capacitors in line with the alternator leads

20. - E5A02

What is resonance in an electrical circuit?

Select	Answer
A	The highest frequency that will pass current
B	The frequency at which the reactive impedance equals the resistive impedance
C	The lowest frequency that will pass current
D	The frequency at which the capacitive reactance equals the inductive reactance

21. - E5B12

What is admittance?

Select	Answer
A	The inverse of impedance
B	The term for the gain of a field effect transistor
C	The turns ratio of a transformer
D	The unit used for Q factor

22. - E5C06

What does the impedance 50-j25 represent?

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

23. - E5D03

What is microstrip?

Select	Answer
A	Lightweight transmission line made of common zip cord
B	Precision printed circuit conductors above a ground plane that provide constant impedance interconnects at microwave frequencies
C	Short lengths of coax mounted on printed circuit boards to minimize time delay between microwave circuits
D	Miniature coax used for low power applications

24. - E6A14

How does DC input impedance at the gate of a field-effect transistor compare with the DC input impedance of a bipolar transistor?

Select	Answer
A	They are both low impedance
B	They are both high impedance
C	An FET has low input impedance; a bipolar transistor has high input impedance
D	An FET has high input impedance; a bipolar transistor has low input impedance

25. - E6B11

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

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

26. - E6C06

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

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

27. - E6D06

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

Select	Answer
A	Resistance
B	Thermal impedance
C	Reactivity
D	Permeability

28. - E6E12

Why are high-power RF amplifier ICs and transistors sometimes mounted in ceramic packages?

Select	Answer
A	High-voltage insulating ability
B	Enhanced sensitivity to light
C	To provide a low-pass frequency response
D	Better dissipation of heat

29. - E6F03

What is the most common configuration of an optoisolator or optocoupler?

Select	Answer
A	A lens and a photomultiplier
B	An LED and a phototransistor
C	An amplitude modulated helium-neon laser
D	A frequency modulated helium-neon laser

30. - E7A08

What logical operation does an OR gate perform?

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

31. - E7B16

What is the effect of intermodulation products in a linear power amplifier?

Select	Answer
A	Creation of parasitic oscillations
B	Transmission of spurious signals
C	All of these choices are correct
D	Low efficiency

32. - E7C13

What is one advantage of a Pi-matching network over an L-matching network consisting of a single inductor and a single capacitor?

Select	Answer
A	Pi-networks have fewer components
B	The Q of Pi-networks can be varied depending on the component values chosen
C	Pi-networks are designed for balanced input and output
D	L-networks cannot perform impedance transformation

33. - E7D07

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

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

34. - E7E03

How does an analog phase modulator function?

Select	Answer
A	By varying the tuning of a microphone preamplifier to produce PM signals
B	By varying the tuning of an amplifier tank circuit to produce PM signals
C	By varying the tuning of an amplifier tank circuit to produce AM signals
D	By varying the tuning of a microphone preamplifier to produce AM signals

35. - E7F08

What is the function of decimation with regard to digital filters?

Select	Answer
A	Converting data to binary code decimal form
B	Reducing the effective sample rate by removing samples
C	Removing unnecessary significant digits
D	Attenuating the signal

36. - E7G08

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

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

37. - E7H10

What information is contained in the lookup table of a direct digital frequency synthesizer?

Select	Answer
A	The synthesizer frequency limits and frequency values stored in the radio memories
B	The amplitude values that represent a sine-wave output
C	The phase relationship between a voltage-controlled oscillator and the output waveform
D	The phase relationship between a reference oscillator and the output waveform

38. - E8A05

What would be the most accurate way of measuring the RMS voltage of a complex waveform?

Select	Answer
A	By measuring the voltage with a D'Arsonval meter
B	By using an absorption wave meter
C	By measuring the heating effect in a known resistor
D	By using a grid dip meter

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. - 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. - E8D08

What parameter might indicate that excessively high input levels are causing distortion in an AFSK signal?

Select	Answer
A	Baud rate
B	Repeat Request Rate (RRR)
C	Intermodulation Distortion (IMD)
D	Signal to noise ratio

42. - E9A05

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

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

43. - E9B02

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

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

44. - E9C10

Which of the following describes a Zepp antenna?

Select	Answer
A	An end fed dipole antenna
B	A vertical array capable of quickly changing the direction of maximum radiation by changing phasing lines
C	An omni-directional antenna commonly used for satellite communications
D	A dipole constructed from zip cord

45. - E9D03

Where should a high Q loading coil be placed to minimize losses in a shortened vertical antenna?

Select	Answer
A	As low as possible on the vertical radiator
B	At a voltage node
C	As close to the transmitter as possible
D	Near the center of the vertical radiator

46. - E9E04

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

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

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

48. - E9G08

What is the process of normalization with regard to a Smith chart?

Select	Answer
A	Reassigning impedance values with regard to the prime center
B	Reassigning reactance values with regard to the resistance axis
C	Reassigning prime center with regard to the reactance axis
D	Reassigning resistance values with regard to the reactance axis

49. - E9H04

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

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

50. - E0A10

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

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

Figure E7-3

Figure E9-1