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

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 participating in the Military Auxiliary Radio System (MARS)
D	Any FCC-licensed amateur station certified by the responsible civil defense organization for the area served

3. - E1C08

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

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

4. - E1D08

Which VHF amateur service bands have frequencies available for space stations?

Select	Answer
A	6 meters and 2 meters
B	6 meters, 2 meters, and 1.25 meters
C	2 meters
D	2 meters and 1.25 meters

5. - E1E10

What must the administering VEs do after the administration of a successful examination for an amateur operator license?

Select	Answer
A	They must submit the application document to the coordinating VEC according to the coordinating VEC instructions
B	They must collect and send the documents to the FCC according to instructions
C	They must collect and send the documents to the NCVEC for grading
D	They must collect and submit the documents to the coordinating VEC for grading

6. - E1F02

What privileges are authorized in the U.S. to persons holding an amateur service license granted by the Government of Canada?

Select	Answer
A	None, they must obtain a U.S. license
B	The operating terms and conditions of the Canadian amateur service license, not to exceed U.S. Extra Class privileges
C	All privileges of the Extra Class license
D	Full privileges, up to and including those of the Extra Class License, on the 80, 40, 20, 15, and 10 meter bands

7. - E2A03

What is the orbital period of an Earth satellite?

Select	Answer
A	The time it takes for a satellite to travel from perigee to apogee
B	The point of minimum height of a satellite's orbit
C	The time it takes for a satellite to complete one revolution around the Earth
D	The point of maximum height of a satellite's orbit

8. - E2B07

What is the name of the signal component that carries color information in NTSC video?

Select	Answer
A	Hue
B	Chroma
C	Luminance
D	Spectral Intensity

9. - E2C04

What type of transmission is most often used for a ham radio mesh network?

Select	Answer
A	Multiple Frequency Shift Keying in the 10 GHz band
B	Store and forward on the 440 MHz band
C	Spread spectrum in the 2.4 GHz band
D	Frequency division multiplex in the 24 GHz band

10. - E2D02

Which of the following is a good technique for making meteor scatter contacts?

Select	Answer
A	Use of high speed CW or digital modes
B	All of these choices are correct
C	15 second timed transmission sequences with stations alternating based on location
D	Short transmission with rapidly repeated call signs and signal reports

11. - E2E05

Which type of digital mode does not support keyboard-to-keyboard operation?

Select	Answer
A	PSK31
B	Winlink
C	RTTY
D	MFSK

12. - E3A11

What is a typical range for tropospheric propagation of microwave signals?

Select	Answer
A	100 miles to 300 miles
B	1200 miles
C	10 miles to 50 miles
D	2500 miles

13. - E3B12

What is the primary characteristic of chordal hop propagation?

Select	Answer
A	Signals reflected back toward the transmitting station
B	Propagation across the geomagnetic equator
C	Propagation away from the great circle bearing between stations
D	Successive ionospheric reflections without an intermediate reflection from the ground

14. - E3C15

What might a sudden rise in radio background noise indicate?

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

15. - E4A12

Which of the following procedures is an important precaution to follow when connecting a spectrum analyzer to a transmitter output?

Select	Answer
A	Use high quality double shielded coaxial cables to reduce signal losses
B	All of these choices are correct
C	Attenuate the transmitter output going to the spectrum analyzer
D	Match the antenna to the load

16. - E4B16

Which S parameter represents return loss or SWR?

Select	Answer
A	S12
B	S21
C	S11
D	S22

17. - E4C06

A CW receiver with the AGC off has an equivalent input noise power density of -174 dBm/Hz. What would be the level of an unmodulated carrier input to this receiver that would yield an audio output SNR of 0 dB in a 400 Hz noise bandwidth?

Select	Answer
A	-155 dBm
B	-148 dBm
C	-174 dBm
D	-164 dBm

18. - E4D14

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

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

19. - E4E13

What might be the cause of a loud roaring or buzzing AC line interference that comes and goes at intervals?

Select	Answer
A	All of these choices are correct
B	Arcing contacts in a thermostatically controlled device
C	A malfunctioning illuminated advertising display
D	A defective doorbell or doorbell transformer inside a nearby residence

20. - E5A13

What is an effect of increasing Q in a resonant circuit?

Select	Answer
A	Parasitic effects are minimized
B	Fewer components are needed for the same performance
C	Phase shift can become uncontrolled
D	Internal voltages and circulating currents increase

21. - E5B13

What letter is commonly used to represent susceptance?

Select	Answer
A	X
B	B
C	Y
D	G

22. - E5C05

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

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

23. - E5D12

How many watts are consumed in a circuit having a power factor of 0.2 if the input is 100-VAC at 4 amperes?

Select	Answer
A	400 watts
B	80 watts
C	50 watts
D	2000 watts

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 high-power audio circuits
C	In very low frequency RF circuits
D	In microwave circuits

25. - E6B07

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

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

26. - E6C13

Which of the following is an advantage of BiCMOS logic?

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

27. - E6D04

Which materials are commonly used as a slug core in a variable inductor?

Select	Answer
A	Cobalt and aluminum
B	Ferrite and brass
C	Polystyrene and polyethylene
D	Teflon and Delrin

28. - E6E08

How is voltage from a power supply normally furnished to the most common type of monolithic microwave integrated circuit (MMIC)?

Select	Answer
A	Through a resistor and/or RF choke connected to the amplifier output lead
B	Through a capacitor and RF choke connected to the amplifier input lead
C	Directly to the bias voltage (VCC IN) lead
D	MMICs require no operating bias

29. - E6F02

What happens to the conductivity of a photoconductive material when light shines on it?

Select	Answer
A	It stays the same
B	It becomes unstable
C	It increases
D	It decreases

30. - E7A02

What is the function of a decade counter digital IC?

Select	Answer
A	It produces ten output pulses for every input pulse
B	It adds two decimal numbers together
C	It produces one output pulse for every ten input pulses
D	It decodes a decimal number for display on a seven segment LED display

31. - E7B12

What type of amplifier circuit is shown in Figure E7-1?

Select	Answer
A	Common base
B	Common collector
C	Emitter follower
D	Common emitter

32. - E7C08

Which of the following factors has the greatest effect in helping determine the bandwidth and response shape of a crystal ladder filter?

Select	Answer
A	The gain of the RF stage preceding the filter
B	The amplitude of the signals passing through the filter
C	The DC voltage applied to the quartz crystal
D	The relative frequencies of the individual crystals

33. - E7D06

What is the purpose of Q1 in the circuit shown in Figure E7-3?

Select	Answer
A	It provides negative feedback to improve regulation
B	It provides D1 with current
C	It increases the current-handling capability of the regulator
D	It provides a constant load for the voltage source

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 frequency components present in the modulating signal
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	More taps
B	Double-precision math routines
C	Complex phasor representations
D	Higher data rate

36. - E7G11

What absolute voltage gain can be expected from the circuit in Figure E7-4 when R1 is 3300 ohms and RF is 47 kilohms?

Select	Answer
A	7
B	0.07
C	28
D	14

37. - E7H02

Which describes a microphonic?

Select	Answer
A	An IC used for amplifying microphone signals
B	Distortion caused by RF pickup on the microphone cable
C	Changes in oscillator frequency due to mechanical vibration
D	Excess loading of the microphone by an oscillator

38. - E8A08

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

Select	Answer
A	Very low power consumption decreases frequency drift
B	All of these choices are correct
C	Immunity to out of sequence coding reduces spurious responses
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	Percentage of modulation
B	Modulation index
C	Quieting index
D	FM compressibility

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

41. - E8D03

How does the spread spectrum technique of frequency hopping work?

Select	Answer
A	A pseudo-random binary bit stream is used to shift the phase of an RF carrier very rapidly in a particular sequence
B	The frequency of the transmitted signal is changed very rapidly according to a particular sequence also used by the receiving station
C	If interference is detected by the receiver it will signal the transmitter to wait until the frequency is clear
D	If interference is detected by the receiver it will signal the transmitter to change frequencies

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

43. - E9B09

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

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

44. - E9C13

What is the main effect of placing a vertical antenna over an imperfect ground?

Select	Answer
A	It changes the impedance angle of the matching network
B	It causes increased SWR
C	It reduces losses in the radiating portion of the antenna
D	It reduces low-angle radiation

45. - E9D03

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

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

46. - E9E07

What term best describes the interactions at the load end of a mismatched transmission line?

Select	Answer
A	Characteristic impedance
B	Dielectric constant
C	Velocity factor
D	Reflection coefficient

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	Very high impedance
D	The same as the characteristic impedance of the line

48. - E9G01

Which of the following can be calculated using a Smith chart?

Select	Answer
A	Radio propagation
B	Radiation resistance
C	Impedance along transmission lines
D	Antenna radiation pattern

49. - E9H11

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

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

50. - E0A01

What is the primary function of an external earth connection or ground rod?

Select	Answer
A	Lightning protection
B	Reduce RF current flow between pieces of equipment
C	Reduce RFI to telephones and home entertainment systems
D	Reduce received noise

Figure E7-1

Figure E7-3

Figure E7-4