US Amateur Radio - Amateur Extra (Element 4, 2020-2024) Practice Test

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1. - E0A02

When evaluating RF exposure levels from your station at a neighbor's home, what must you do?

Select	Answer
A	Ensure signals from your station are less than the controlled Maximum Permitted Emission (MPE) limits
B	Ensure signals from your station are less than the controlled Maximum Permitted Exposure (MPE) limits
C	Ensure signals from your station are less than the uncontrolled Maximum Permitted Emission (MPE) limits
D	Ensure signals from your station are less than the uncontrolled Maximum Permitted Exposure (MPE) limits

2. - E1A03

What is the maximum legal carrier frequency on the 20 meter band for transmitting USB AFSK digital signals having a 1 kHz bandwidth?

Select	Answer
A	14.349 MHz
B	14.070 MHz
C	14.149 MHz
D	14.100 MHz

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

4. - E1C06

Which of the following is required in order to operate in accordance with CEPT rules in foreign countries where permitted?

Select	Answer
A	You must identify in the official language of the country in which you are operating
B	You must append "/CEPT" to your call sign
C	You must bring a copy of FCC Public Notice DA 16-1048
D	The U.S. embassy must approve of your operation

5. - E1D11

Which amateur stations are eligible to operate as Earth stations?

Select	Answer
A	Any amateur station, subject to the privileges of the class of operator license held by the control operator
B	Only those of General, Advanced or Amateur Extra Class operators
C	Any amateur station whose licensee has filed a pre-space notification with the FCC's International Bureau
D	Only those of Amateur Extra Class operators

6. - E1E09

What may be the penalty for a VE who fraudulently administers or certifies an examination?

Select	Answer
A	All these choices are correct
B	Revocation of the VE's amateur station license grant and the suspension of the VE's amateur operator license grant
C	A fine of up to $1000 per occurrence
D	A sentence of up to one year in prison

7. - E1F08

Which of the following types of amateur station communications are prohibited?

Select	Answer
A	Communications in a language other than English
B	Communications transmitted for hire or material compensation, except as otherwise provided in the rules
C	Communications that have political content, except as allowed by the Fairness Doctrine
D	Communications that have religious content

8. - E2A08

Why should effective radiated power to a satellite that uses a linear transponder be limited?

Select	Answer
A	To prevent creating errors in the satellite telemetry
B	To avoid reducing the downlink power to all other users
C	To prevent the satellite from emitting out-of-band signals
D	To avoid interfering with terrestrial QSOs

9. - E2B04

How is color information sent in analog SSTV?

Select	Answer
A	Color is amplitude modulated on the frequency modulated intensity signal
B	Color lines are sent sequentially
C	Color information is sent on a 2.8 kHz subcarrier
D	Color is sent in a color burst at the end of each line

10. - E2C08

Which of the following contacts may be confirmed through the U.S. QSL bureau system?

Select	Answer
A	Contacts using tactical call signs
B	Repeater contacts between U.S. club members
C	Contacts between a U.S. station and a non-U.S. station
D	Special event contacts between stations in the U.S.

11. - E2D06

Which of the following describes a method of establishing EME contacts?

Select	Answer
A	Judging optimum transmission times by monitoring beacons reflected from the moon
B	High-speed CW identification to avoid fading
C	Time synchronous transmissions alternately from each station
D	Storing and forwarding digital messages

12. - E2E11

What is the difference between direct FSK and audio FSK?

Select	Answer
A	Direct FSK can transmit faster baud rates
B	Direct FSK applies the data signal to the transmitter VFO, while AFSK transmits tones via phone
C	Only direct FSK can be decoded by computer
D	Direct FSK occupies less bandwidth

13. - E3A10

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

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

14. - E3B04

What is meant by the terms "extraordinary" and "ordinary" waves?

Select	Answer
A	Extraordinary waves describe rare long-skip propagation compared to ordinary waves, which travel shorter distances
B	Long-path and short-path waves
C	Refracted rays and reflected waves
D	Independent waves created in the ionosphere that are elliptically polarized

15. - E3C02

What is indicated by a rising A or K index?

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

16. - E4A01

Which of the following limits the highest frequency signal that can be accurately displayed on a digital oscilloscope?

Select	Answer
A	All these choices are correct
B	Q of the circuit
C	Sampling rate of the analog-to-digital converter
D	Amount of memory

17. - E4B08

Which of the following can be used to measure the Q of a series-tuned circuit?

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

18. - E4C04

What is the noise figure of a receiver?

Select	Answer
A	The ratio in dB of the noise generated by the receiver to the theoretical minimum noise
B	The ratio of atmospheric noise to phase noise
C	The ratio of the noise bandwidth in hertz to the theoretical bandwidth of a resistive network
D	The ratio of thermal noise to atmospheric noise

19. - E4D07

Which of the following reduces the likelihood of receiver desensitization?

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

20. - E4E01

What problem can occur when using an automatic notch filter (ANF) to remove interfering carriers while receiving CW signals?

Select	Answer
A	Received CW signals will appear to be modulated at the DSP clock frequency
B	Removal of the CW signal as well as the interfering carrier
C	Any nearby signal passing through the DSP system will overwhelm the desired signal
D	Ringing in the DSP filter will completely remove the spaces between the CW characters

21. - E5A06

What is the magnitude of the circulating current within the components of a parallel LC circuit at resonance?

Select	Answer
A	It equals 2 multiplied by pi, multiplied by frequency, multiplied by inductance
B	It is at a minimum
C	It is at a maximum
D	It equals 1 divided by the quantity 2 times pi, multiplied by the square root of inductance L multiplied by capacitance C

22. - E5B12

What is admittance?

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

23. - E5C01

Which of the following represents capacitive reactance in rectangular notation?

Select	Answer
A	Omega
B	+jX
C	Delta
D	-jX

24. - 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	2000 watts
B	80 watts
C	400 watts
D	50 watts

25. - E6A12

Why do many MOSFET devices have internally connected Zener diodes on the gates?

Select	Answer
A	To protect the substrate from excessive voltages
B	To reduce the chance of static damage to the gate
C	To provide a voltage reference for the correct amount of reverse-bias gate voltage
D	To keep the gate voltage within specifications and prevent the device from overheating

26. - E6B09

What is a common use for point-contact diodes?

Select	Answer
A	As a constant voltage source
B	As a high-voltage rectifier
C	As a constant current source
D	As an RF detector

27. - E6C01

What is the function of hysteresis in a comparator?

Select	Answer
A	To allow the comparator to be used with AC input signals
B	To prevent input noise from causing unstable output signals
C	To increase the sensitivity
D	To cause the output to change states continually

28. - E6D01

Why should core saturation of an impedance matching transformer be avoided?

Select	Answer
A	Harmonics and distortion could result
B	Temporary changes of the core permeability could result
C	RF susceptance would increase
D	Magnetic flux would increase with frequency

29. - E6E06

What characteristics of the MMIC make it a popular choice for VHF through microwave circuits?

Select	Answer
A	Nearly infinite gain, very high input impedance, and very low output impedance
B	The ability to retrieve information from a single signal even in the presence of other strong signals
C	Plate current that is controlled by a control grid
D	Controlled gain, low noise figure, and constant input and output impedance over the specified frequency range

30. - E6F01

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

Select	Answer
A	Holes
B	Photons
C	Electrons
D	Protons

31. - 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

32. - E7B17

Why are odd-order rather than even-order intermodulation distortion products of concern in linear power amplifiers?

Select	Answer
A	Because they are relatively far in frequency from the desired signal
B	Because they maintain the sidebands, thus causing multiple duplicate signals
C	Because they invert the sidebands causing distortion
D	Because they are relatively close in frequency to the desired signal

33. - E7C11

Which of the following describes a receiving filter's ability to reject signals occupying an adjacent channel?

Select	Answer
A	Noise factor
B	Shape factor
C	Passband ripple
D	Phase response

34. - E7D15

What is the purpose of a step-start circuit in a high-voltage power supply?

Select	Answer
A	To compensate for variations of the incoming line voltage
B	To allow the filter capacitors to charge gradually
C	To allow for remote control of the power supply
D	To provide a dual-voltage output for reduced power applications

35. - E7E11

Which type of detector circuit is used for demodulating SSB signals?

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

36. - E7F09

Why is an anti-aliasing digital filter required in a digital decimator?

Select	Answer
A	It removes high-frequency signal components that would otherwise be reproduced as lower frequency components
B	It removes low-frequency signal components to eliminate the need for DC restoration
C	It notches out the sampling frequency to avoid sampling errors
D	It peaks the response of the decimator, improving bandwidth

37. - E7G09

What will be the output voltage of the circuit shown in Figure E7-3 if R1 is 1000 ohms, RF is 10,000 ohms, and 0.23 volts DC is applied to the input?

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

38. - E7H07

How can an oscillator's microphonic responses be reduced?

Select	Answer
A	Use NP0 capacitors
B	Mechanically isolate the oscillator circuitry from its enclosure
C	Reduce noise on the oscillator's power supply
D	Increase the bias voltage

39. - E8A05

What of the following instruments would be the most accurate for measuring the RMS voltage of a complex waveform?

Select	Answer
A	A D'Arsonval meter
B	A true-RMS calculating meter
C	An absorption wave meter
D	A grid dip meter

40. - E8B08

What describes Orthogonal Frequency Division Multiplexing?

Select	Answer
A	A bandwidth compression technique using Fourier transforms
B	A digital mode for narrow-band, slow-speed transmissions
C	A digital modulation technique using subcarriers at frequencies chosen to avoid intersymbol interference
D	A frequency modulation technique that uses non-harmonically related frequencies

41. - E8C01

How is Forward Error Correction implemented?

Select	Answer
A	By the receiving station repeating each block of three data characters
B	By transmitting extra data that may be used to detect and correct transmission errors
C	By varying the frequency shift of the transmitted signal according to a predefined algorithm
D	By transmitting a special algorithm to the receiving station along with the data characters

42. - E8D09

What is considered an acceptable maximum IMD level for an idling PSK signal?

Select	Answer
A	+15 dB
B	-30 dB
C	-20 dB
D	+10 dB

43. - E9A05

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

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

44. - E9B03

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

Select	Answer
A	18 dB
B	12 dB
C	24 dB
D	14 dB

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

46. - E9D12

Which of the following would provide the best RF ground for your station?

Select	Answer
A	A 50-ohm resistor connected to ground
B	An electrically short connection to 3 or 4 interconnected ground rods via a series RF choke
C	An electrically short connection to a metal water pipe
D	An electrically short connection to 3 or 4 interconnected ground rods driven into the Earth

47. - E9E01

What system matches a higher-impedance transmission line to a lower-impedance antenna by connecting the line to the driven element in two places spaced a fraction of a wavelength each side of element center?

Select	Answer
A	The gamma matching system
B	The delta matching system
C	The omega matching system
D	The stub matching system

48. - E9F06

What is the approximate physical length of an air-insulated, parallel conductor transmission line that is electrically 1/2 wavelength long at 14.10 MHz?

Select	Answer
A	7.0 meters
B	8.5 meters
C	10.6 meters
D	13.3 meters

49. - E9G11

How are the wavelength scales on a Smith chart calibrated?

Select	Answer
A	In fractions of antenna electrical wavelength
B	In fractions of antenna electrical frequency
C	In fractions of transmission line electrical frequency
D	In fractions of transmission line electrical wavelength

50. - E9H08

What is the function of a sense antenna?

Select	Answer
A	It allows DF antennas to receive signals at different vertical angles
B	It increases the sensitivity of a DF antenna array
C	It provides diversity reception that cancels multipath signals
D	It modifies the pattern of a DF antenna array to provide a null in one direction

Figure E7-3

Figure E9-1