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

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1. - E1A07

Which amateur band requires transmission on specific channels rather than on a range of frequencies?

Select	Answer
A	30 meter band
B	17 meter band
C	12 meter band
D	60 meter band

2. - E1B08

What limitations may the FCC place on an amateur station if its signal causes interference to domestic broadcast reception, assuming that the receivers involved are of good engineering design?

Select	Answer
A	The amateur station must cease operation on all frequencies below 30 MHz
B	The amateur station must cease operation
C	The amateur station must avoid transmitting during certain hours on frequencies that cause the interference
D	The amateur station must cease operation on all frequencies above 30 MHz

3. - E1C02

What is meant by automatic control of a station?

Select	Answer
A	Remotely controlling a station's antenna pattern through a directional control link
B	The use of a control link between a control point and a locally controlled station
C	The use of devices and procedures for control so that the control operator does not have to be present at a control point
D	A station operating with its output power controlled automatically

4. - E1D10

Which amateur stations are eligible to be telecommand stations?

Select	Answer
A	Any amateur station designated by NASA
B	All of these choices are correct
C	Any amateur station so designated by the space station licensee, subject to the privileges of the class of operator license held by the control operator
D	Any amateur station so designated by the ITU

5. - E1E01

What is the minimum number of qualified VEs required to administer an Element 4 amateur operator license examination?

Select	Answer
A	2
B	5
C	3
D	4

6. - E1F03

Under what circumstances may a dealer sell an external RF power amplifier capable of operation below 144 MHz if it has not been granted FCC certification?

Select	Answer
A	It was imported from a manufacturer in a country that does not require certification of RF power amplifiers
B	It was imported from a manufacturer in another country and was certificated by that country's government
C	The equipment dealer assembled it from a kit
D	It was purchased in used condition from an amateur operator and is sold to another amateur operator for use at that operator's station

7. - E2A04

What is meant by the term mode as applied to an amateur radio satellite?

Select	Answer
A	The type of signals that can be relayed through the satellite
B	The satellite's uplink and downlink frequency bands
C	Whether the satellite is in a polar or equatorial orbit
D	The satellite's orientation with respect to the Earth

8. - E2B03

How is an interlaced scanning pattern generated in a fast-scan (NTSC) television system?

Select	Answer
A	By scanning lines from left to right in one field and right to left in the next
B	By scanning each field from bottom to top
C	By scanning two fields simultaneously
D	By scanning odd numbered lines in one field and even numbered lines in the next

9. - E2C11

How should you generally identify your station when attempting to contact a DX station during a contest or in a pileup?

Select	Answer
A	Send the call sign of the DX station three times, the words "this is", then your call sign three times
B	Send your full call sign and grid square
C	Send only the last two letters of your call sign until you make contact
D	Send your full call sign once or twice

10. - E2D14

What is one advantage of using JT65 coding?

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

11. - E2E05

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

Select	Answer
A	MFSK
B	PSK31
C	RTTY
D	Winlink

12. - E3A10

Which type of atmospheric structure can create a path for microwave propagation?

Select	Answer
A	The jet stream
B	Temperature inversion
C	Dust devil
D	Wind shear

13. - E3B13

Why is chordal hop propagation desirable?

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

14. - E3C07

Which of the following descriptors indicates the greatest solar flare intensity?

Select	Answer
A	Class X
B	Class B
C	Class M
D	Class A

15. - E4A04

What determines the upper frequency limit for a computer soundcard-based oscilloscope program?

Select	Answer
A	All of these choices are correct
B	Amount of memory on the soundcard
C	Analog-to-digital conversion speed of the soundcard
D	Q of the interface of the interface circuit

16. - E4B05

If a frequency counter with a specified accuracy of +/- 10 ppm reads 146,520,000 Hz, what is the most the actual frequency being measured could differ from the reading?

Select	Answer
A	146.52 kHz
B	146.52 Hz
C	1465.20 Hz
D	10 Hz

17. - E4C10

Which of the following is a desirable amount of selectivity for an amateur RTTY HF receiver?

Select	Answer
A	100 Hz
B	300 Hz
C	6000 Hz
D	2400 Hz

18. - E4D13

Which of the following can cause receiver desensitization?

Select	Answer
A	Strong adjacent channel signals
B	Audio bias adjusted too high
C	Audio gain adjusted too low
D	Squelch gain misadjusted

19. - E4E02

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

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

20. - E5A10

How is the Q of an RLC series resonant circuit calculated?

Select	Answer
A	Reactance of either the inductance or capacitance divided by the resistance
B	Resistance divided by the reactance of either the inductance or capacitance
C	Reactance of either the inductance or capacitance times the resistance
D	Reactance of the inductance times the reactance of the capacitance

21. - E5B08

What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 100 ohms, R is 100 ohms, and XL is 75 ohms?

Select	Answer
A	14 degrees with the voltage leading the current
B	14 degrees with the voltage lagging the current
C	76 degrees with the voltage lagging the current
D	76 degrees with the voltage leading the current

22. - E5C04

Which of the following represents a capacitive reactance in polar coordinates?

Select	Answer
A	A positive phase angle
B	A positive real part
C	A negative phase angle
D	A negative real part

23. - E5D02

Why is it important to keep lead lengths short for components used in circuits for VHF and above?

Select	Answer
A	To increase the thermal time constant
B	To avoid unwanted inductive reactance
C	To maintain component lifetime
D	All of these choices are correct

24. - E6A15

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

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

25. - E6B02

What is an important characteristic of a Schottky diode as compared to an ordinary silicon diode when used as a power supply rectifier?

Select	Answer
A	Enhanced carrier retention time
B	Less forward voltage drop
C	Controlled reverse avalanche voltage
D	Much higher reverse voltage breakdown

26. - E6C13

Which of the following is an advantage of BiCMOS logic?

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

27. - E6D01

How many turns will be required to produce a 5-microhenry inductor using a powdered-iron toroidal core that has an inductance index (A L) value of 40 microhenrys/100 turns?

Select	Answer
A	35 turns
B	79 turns
C	13 turns
D	141 turns

28. - E6E02

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

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

29. - E6F12

What absorbs the energy from light falling on a photovoltaic cell?

Select	Answer
A	Protons
B	Electrons
C	Photons
D	Holes

30. - E7A12

What type of logic defines "0" as a high voltage?

Select	Answer
A	Negative logic
B	Assertive Logic
C	Positive Logic
D	Reverse Logic

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	Switching amplifiers operate at higher voltages
D	The power transistor is at saturation or cut off most of the time, resulting in low power dissipation

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. - E7D04

Which of the following types of linear voltage regulator usually make the most efficient use of the primary power source?

Select	Answer
A	A series regulator
B	A series current source
C	A shunt regulator
D	A shunt current source

34. - E7E01

Which of the following can be used to generate FM phone emissions?

Select	Answer
A	A balanced modulator on the audio amplifier
B	A balanced modulator on the oscillator
C	A reactance modulator on the final amplifier
D	A reactance modulator on the oscillator

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	10 bits
C	8 bits
D	4 bits

36. - E7G10

What absolute voltage gain can be expected from the circuit in Figure E7-4 when R1 is 1800 ohms and RF is 68 kilohms?

Select	Answer
A	1
B	38
C	76
D	0.03

37. - E7H07

How can an oscillator's microphonic responses be reduced?

Select	Answer
A	Using the oscillator only for CW and digital signals
B	Eliminating noise on the oscillator's power supply
C	Use of NP0 capacitors
D	Mechanically isolating the oscillator circuitry from its enclosure

38. - E8A06

What is the approximate ratio of PEP-to-average power in a typical single-sideband phone signal?

Select	Answer
A	25 to 1
B	100 to 1
C	2.5 to 1
D	1 to 1

39. - E8B03

What is the modulation index of an FM-phone signal having a maximum frequency deviation of 3000 Hz either side of the carrier frequency when the modulating frequency is 1000 Hz?

Select	Answer
A	3
B	1000
C	3000
D	0.3

40. - E8C09

Which is the name of a digital code where each preceding or following character changes by only one bit?

Select	Answer
A	Excess 3 code
B	Binary Coded Decimal Code
C	Gray code
D	Extended Binary Coded Decimal Interchange Code

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	The generation of key clicks
C	Limits data speed
D	More difficult to copy

42. - E9A03

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

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

43. - E9B15

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

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

44. - E9C10

Which of the following describes a Zepp antenna?

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

45. - E9D10

What happens to feed point impedance at the base of a fixed length HF mobile antenna as the frequency of operation is lowered?

Select	Answer
A	The radiation resistance decreases and the capacitive reactance decreases
B	The radiation resistance decreases and the capacitive reactance increases
C	The radiation resistance increases and the capacitive reactance increases
D	The radiation resistance increases and the capacitive reactance decreases

46. - E9E07

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

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

47. - E9F03

Why is the physical length of a coaxial cable transmission line shorter than its electrical length?

Select	Answer
A	The characteristic impedance is higher in a parallel feed line
B	Electrical signals move more slowly in a coaxial cable than in air
C	The surge impedance is higher in a parallel feed line
D	Skin effect is less pronounced in the coaxial cable

48. - E9G07

On the Smith chart shown in Figure E9-3, what is the only straight line shown?

Select	Answer
A	The voltage axis
B	The resistance axis
C	The reactance axis
D	The current axis

49. - E9H11

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

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

50. - E0A01

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

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

Figure E7-4

Figure E9-2

Figure E9-3