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	60 Hz
B	170 Hz
C	1.5 kHz
D	2.8 kHz

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

3. - E1C07

What is meant by local control?

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

4. - E1D09

Which UHF amateur service bands have frequencies available for a space station?

Select	Answer
A	70 cm only
B	70 cm and 13 cm
C	33 cm and 13 cm
D	70 cm and 33 cm

5. - E1E06

Who is responsible for the proper conduct and necessary supervision during an amateur operator license examination session?

Select	Answer
A	The FCC
B	The VEC coordinating the session
C	Each administering VE
D	The VE session manager

6. - E1F06

Under what circumstances might the FCC issue a Special Temporary Authority (STA) to an amateur station?

Select	Answer
A	To provide temporary operation while awaiting normal licensing
B	To provide for experimental amateur communications
C	To provide additional spectrum for personal use
D	To allow regular operation on Land Mobile channels

7. - E2A10

Why may the received signal from an amateur satellite exhibit a rapidly repeating fading effect?

Select	Answer
A	Because of the Doppler Effect
B	Because of ionospheric absorption
C	Because of the satellite's low orbital altitude
D	Because the satellite is spinning

8. - E2B16

Which is a video standard used by North American Fast Scan ATV stations?

Select	Answer
A	DRM
B	PAL
C	NTSC
D	Scottie

9. - E2C07

What is the Cabrillo format?

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

10. - E2D03

Which of the following digital modes is especially useful for EME communications?

Select	Answer
A	FSK441
B	JT65
C	PACTOR III
D	Olivia

11. - E2E12

Which type of control is used by stations using the Automatic Link Enable (ALE) protocol?

Select	Answer
A	Local
B	ALE can use any type of control
C	Remote
D	Automatic

12. - E3A03

When scheduling EME contacts, which of these conditions will generally result in the least path loss?

Select	Answer
A	When the Moon is at apogee
B	When the Moon is full
C	When the Moon is at perigee
D	When the MUF is above 30 MHz

13. - E3B08

What type of HF propagation is probably occurring if radio signals travel along the terminator between daylight and darkness?

Select	Answer
A	Transequatorial
B	Sporadic-E
C	Gray-line
D	Long-path

14. - E3C08

What does the space weather term G5 mean?

Select	Answer
A	An extreme geomagnetic storm
B	Very low solar activity
C	Moderate solar wind
D	Waning sunspot numbers

15. - E4A10

Which of the following displays multiple digital signal states simultaneously?

Select	Answer
A	Network analyzer
B	Modulation monitor
C	Bit error rate tester
D	Logic analyzer

16. - E4B15

Which of the following can be used as a relative measurement of the Q for a series-tuned circuit?

Select	Answer
A	The bandwidth of the circuit's frequency response
B	The frequency shift
C	The resonant frequency of the circuit
D	The inductance to capacitance ratio

17. - E4C07

What does the MDS of a receiver represent?

Select	Answer
A	The multiplex distortion stability
B	The maximum detectable spectrum
C	The meter display sensitivity
D	The minimum discernible signal

18. - E4D11

Why are third-order intermodulation products created within a receiver of particular interest compared to other products?

Select	Answer
A	Third-order intermodulation produces three products for every input signal within the band of interest
B	The third-order intercept is much higher than other orders
C	Third-order products are an indication of poor image rejection
D	The third-order product of two signals which are in the band of interest is also likely to be within the band

19. - E4E09

What undesirable effect can occur when using an IF noise blanker?

Select	Answer
A	The audio frequency bandwidth of the received signal might be compressed
B	Nearby signals may appear to be excessively wide even if they meet emission standards
C	Received audio in the speech range might have an echo effect
D	FM signals can no longer be demodulated

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	Reactance of the inductance times the reactance of the capacitance
C	Resistance divided by the reactance of either the inductance or capacitance
D	Reactance of either the inductance or capacitance times the resistance

21. - E5B03

What happens to the phase angle of a reactance when it is converted to a susceptance?

Select	Answer
A	It is shifted by 90 degrees
B	The susceptance phase angle is the inverse of the reactance phase angle
C	The sign is reversed
D	It is unchanged

22. - E5C16

Which point on Figure E5-2 best represents the impedance of a series circuit consisting of a 300 ohm resistor and a 19 picofarad capacitor at 21.200 MHz?

Select	Answer
A	Point 3
B	Point 1
C	Point 8
D	Point 7

23. - E5D09

What happens to reactive power in an AC circuit that has both ideal inductors and ideal capacitors?

Select	Answer
A	It is repeatedly exchanged between the associated magnetic and electric fields, but is not dissipated
B	It is dissipated in the formation of inductive and capacitive fields
C	It is dissipated as kinetic energy in the circuit
D	It is dissipated as heat in the circuit

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

25. - E6B13

What type of bias is required for an LED to emit light?

Select	Answer
A	Zero bias
B	Inductive bias
C	Forward bias
D	Reverse bias

26. - E6C13

Which of the following is an advantage of BiCMOS logic?

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

27. - E6D06

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

Select	Answer
A	Thermal impedance
B	Resistance
C	Reactivity
D	Permeability

28. - E6E04

Which is the most common input and output impedance of circuits that use MMICs?

Select	Answer
A	10 ohms
B	50 ohms
C	300 ohms
D	450 ohms

29. - E6F13

What is a liquid crystal display (LCD)?

Select	Answer
A	A frequency-determining unit for a transmitter or receiver
B	A display that uses a glowing liquid to remain brightly lit in dim light
C	A modern replacement for a quartz crystal oscillator which displays its fundamental frequency
D	A display utilizing a crystalline liquid and polarizing filters which becomes opaque when voltage is applied

30. - E7A12

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

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

31. - E7B12

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

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

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

33. - E7D06

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

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

34. - E7E11

Which type of detector is used for demodulating SSB signals?

Select	Answer
A	Phase detector
B	Product detector
C	Discriminator
D	Phase comparator

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. - 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 does not vary with frequency
D	It increases linearly with increasing frequency

37. - E7H13

Which of the following is a technique for providing highly accurate and stable oscillators needed for microwave transmission and reception?

Select	Answer
A	Use a temperature-controlled high Q dielectric resonator
B	Use a rubidium stabilized reference oscillator
C	All of these choices are correct
D	Use a GPS signal reference

38. - E8A01

What is the name of the process that shows that a square wave is made up of a sine wave plus all of its odd harmonics?

Select	Answer
A	Numerical analysis
B	Differential analysis
C	Fourier analysis
D	Vector analysis

39. - E8B06

What is the deviation ratio of an FM-phone signal having a maximum frequency swing of plus or minus 7.5 kHz when the maximum modulation frequency is 3.5 kHz?

Select	Answer
A	0.214
B	2.14
C	47
D	0.47

40. - E8C04

What technique is used to minimize the bandwidth requirements of a PSK31 signal?

Select	Answer
A	Use of sinusoidal data pulses
B	Use of trapezoidal data pulses
C	Reed-Solomon character encoding
D	Zero-sum character encoding

41. - E8D11

What is one advantage of using ASCII code for data communications?

Select	Answer
A	It uses one character as a shift code to send numeric and special characters
B	It includes built in error correction features
C	It contains fewer information bits per character than any other code
D	It is possible to transmit both upper and lower case text

42. - E9A18

What term describes station output, taking into account all gains and losses?

Select	Answer
A	Effective radiated power
B	Apparent power
C	Half-power bandwidth
D	Power factor

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	18 dB
C	24 dB
D	14 dB

44. - E9C04

What happens to the radiation pattern of an unterminated long wire antenna as the wire length is increased?

Select	Answer
A	The front-to-back ratio decreases
B	The lobes align more in the direction of the wire
C	The lobes become more perpendicular to the wire
D	The vertical angle increases

45. - E9D02

How can linearly polarized Yagi antennas be used to produce circular polarization?

Select	Answer
A	Stack two Yagis fed in phase to form an array with the respective elements in parallel planes
B	Stack two Yagis fed 90 degrees out of phase to form an array with the respective elements in parallel planes
C	Arrange two Yagis collinear to each other with the driven elements fed 180 degrees out of phase
D	Arrange two Yagis perpendicular to each other with the driven elements at the same point on the boom fed 90 degrees out of phase

46. - E9E04

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

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

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

48. - E9G06

On the Smith chart shown in Figure E9-3, what is the name for the large outer circle on which the reactance arcs terminate?

Select	Answer
A	Reactance axis
B	Polar axis
C	Impedance axis
D	Prime axis

49. - E9H04

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

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

50. - E0A05

What is one of the potential hazards of using microwaves in the amateur radio bands?

Select	Answer
A	The extremely high frequency energy can damage the joints of antenna structures
B	Microwaves are ionizing radiation
C	Microwaves often travel long distances by ionospheric reflection
D	The high gain antennas commonly used can result in high exposure levels

Figure E5-2

Figure E7-1

Figure E7-3

Figure E9-1

Figure E9-3