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

Logging in (or registering) will help the system to select questions that you need to focus on.

1. - E1A04

With your transceiver displaying the carrier frequency of phone signals, you hear a DX station calling CQ on 3.601 MHz LSB. Is it legal to return the call using lower sideband on the same frequency?

Select	Answer
A	No, the sideband will extend beyond the edge of the phone band segment
B	No, U.S. stations are not permitted to use phone emissions below 3.610 MHz
C	Yes, because the displayed frequency is within the 75 meter phone band segment
D	Yes, because the DX station initiated the contact

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 file an Environmental Impact Statement with the EPA before construction begins
B	No special rules apply if your antenna structure will be less than 300 feet in height
C	You may have to notify the Federal Aviation Administration and register it with the FCC as required by Part 17 of FCC rules
D	You must obtain a construction permit from the airport zoning authority

3. - E1C12

What types of communications may be transmitted to amateur stations in foreign countries?

Select	Answer
A	Communications incidental to the purpose of the amateur service and remarks of a personal nature
B	Messages intended for connection to users of the maritime satellite service
C	Business-related messages for non-profit organizations
D	All of these choices are correct

4. - E1D02

What is the amateur satellite service?

Select	Answer
A	A radio communications service using amateur radio stations on satellites
B	A spacecraft launching service for amateur-built satellites
C	A radio communications service using stations on Earth satellites for public service broadcast
D	A radio navigation service using satellites for the purpose of self training, intercommunication and technical studies carried out by amateurs

5. - E1E09

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

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

6. - 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 a religious content
D	Communications that have a political content, except as allowed by the Fairness Doctrine

7. - E2A10

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

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

8. - E2B01

How many times per second is a new frame transmitted in a fast-scan (NTSC) television system?

Select	Answer
A	120
B	90
C	30
D	60

9. - E2C03

From which of the following bands is amateur radio contesting generally excluded?

Select	Answer
A	33 cm
B	2 m
C	6 m
D	30 m

10. - E2D06

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

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

11. - E2E10

Which of these digital modes has the narrowest bandwidth?

Select	Answer
A	MFSK16
B	PSK31
C	300-baud packet
D	170 Hz shift, 45 baud RTTY

12. - E3A17

What is meant by circularly polarized electromagnetic waves?

Select	Answer
A	Waves with an electric field bent into a circular shape
B	Waves with a rotating electric field
C	Waves that circle the Earth
D	Waves produced by a loop antenna

13. - E3B10

What is the cause of gray-line propagation?

Select	Answer
A	At midday, the Sun super heats the ionosphere causing increased refraction of radio waves
B	At twilight and sunrise, D-layer absorption is low while E-layer and F-layer propagation remains high
C	At mid-afternoon, the Sun heats the ionosphere decreasing radio wave refraction and the MUF
D	In darkness, solar absorption drops greatly while atmospheric ionization remains steady

14. - E3C13

What type of polarization is best for ground-wave propagation?

Select	Answer
A	Elliptical
B	Horizontal
C	Vertical
D	Circular

15. - E4A01

Which of the following parameter determines the bandwidth of a digital or computer-based oscilloscope?

Select	Answer
A	Sample resolution
B	Input capacitance
C	Input impedance
D	Sampling rate

16. - E4B16

Which S parameter represents return loss or SWR?

Select	Answer
A	S22
B	S21
C	S11
D	S12

17. - E4C05

What does a value of -174 dBm/Hz represent with regard to the noise floor of a receiver?

Select	Answer
A	The noise figure of a 1 Hz bandwidth receiver
B	The minimum detectable signal as a function of receive frequency
C	The galactic noise contribution to minimum detectable signal
D	The theoretical noise at the input of a perfect receiver at room temperature

18. - E4D13

Which of the following can cause receiver desensitization?

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

19. - E4E10

What is a common characteristic of interference caused by a touch controlled electrical device?

Select	Answer
A	The interfering signal sounds like AC hum on an AM receiver or a carrier modulated by 60 Hz hum on a SSB or CW receiver
B	The interfering signal can be several kHz in width and usually repeats at regular intervals across a HF band
C	The interfering signal may drift slowly across the HF spectrum
D	All of these choices are correct

20. - E5A13

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

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

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

22. - E5C02

How are impedances described in polar coordinates?

Select	Answer
A	By X and R values
B	By real and imaginary parts
C	By Y and G values
D	By phase angle and amplitude

23. - E5D11

What is the power factor of an R-L circuit having a 60 degree phase angle between the voltage and the current?

Select	Answer
A	1.414
B	0.866
C	1.73
D	0.5

24. - E6A08

What term indicates the frequency at which the grounded-base current gain of a transistor has decreased to 0.7 of the gain obtainable at 1 kHz?

Select	Answer
A	Beta cutoff frequency
B	Corner frequency
C	Alpha rejection frequency
D	Alpha cutoff frequency

25. - E6B12

What is one common use for PIN diodes?

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

26. - E6C10

In Figure E6-5, what is the schematic symbol for a NOR gate?

Select	Answer
A	1
B	3
C	4
D	2

27. - E6D08

What is one reason for using powdered-iron cores rather than ferrite cores in an inductor?

Select	Answer
A	Powdered-iron cores use smaller diameter wire for the same inductance
B	Powdered-iron cores generally require fewer turns to produce a given inductance
C	Powdered-iron cores generally have greater initial permeability
D	Powdered-iron cores generally maintain their characteristics at higher currents

28. - E6E10

What is the packaging technique in which leadless components are soldered directly to circuit boards?

Select	Answer
A	Stripped lead
B	Virtual lead mounting
C	Direct soldering
D	Surface mount

29. - E6F12

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

Select	Answer
A	Photons
B	Electrons
C	Holes
D	Protons

30. - E7A03

Which of the following can divide the frequency of a pulse train by 2?

Select	Answer
A	An XOR gate
B	A flip-flop
C	An OR gate
D	A multiplexer

31. - E7B09

Which of the following describes how the loading and tuning capacitors are to be adjusted when tuning a vacuum tube RF power amplifier that employs a Pi-network output circuit?

Select	Answer
A	The tuning capacitor is set to maximum capacitance and the loading capacitor is adjusted for minimum plate permissible current
B	The tuning capacitor is adjusted for minimum plate current, and the loading capacitor is adjusted for maximum permissible plate current
C	The loading capacitor is set to maximum capacitance and the tuning capacitor is adjusted for minimum allowable plate current
D	The loading capacitor is adjusted to minimum plate current while alternately adjusting the tuning capacitor for maximum allowable plate current

32. - E7C05

Which filter type is described as having ripple in the passband and a sharp cutoff?

Select	Answer
A	A Butterworth filter
B	A Chebyshev filter
C	An active LC filter
D	A passive op-amp filter

33. - E7D10

What is the primary reason that a high-frequency switching type high voltage power supply can be both less expensive and lighter in weight than a conventional power supply?

Select	Answer
A	It uses a large power factor compensation capacitor to create free power from the unused portion of the AC cycle
B	The inverter design does not require any output filtering
C	The high frequency inverter design uses much smaller transformers and filter components for an equivalent power output
D	It uses a diode bridge rectifier for increased output

34. - E7E04

What is one way a single-sideband phone signal can be generated?

Select	Answer
A	By using a loop modulator followed by a mixer
B	By using a balanced modulator followed by a filter
C	By driving a product detector with a DSB signal
D	By using a reactance modulator followed by a mixer

35. - E7F01

What is meant by direct digital conversion as applied to software defined radios?

Select	Answer
A	Software is converted from source code to object code during operation of the receiver
B	A switching mixer is used to generate I and Q signals directly from the RF input
C	Incoming RF is digitized by an analog-to-digital converter without being mixed with a local oscillator signal
D	Incoming RF is converted to a control voltage for a voltage controlled oscillator

36. - E7G03

What is the typical input impedance of an integrated circuit op-amp?

Select	Answer
A	100 ohms
B	1000 ohms
C	Very low
D	Very high

37. - E7H12

Which of the following must be done to insure that a crystal oscillator provides the frequency specified by the crystal manufacturer?

Select	Answer
A	Provide the crystal with a specified parallel capacitance
B	Bias the crystal at a specified voltage
C	Provide the crystal with a specified parallel inductance
D	Bias the crystal at a specified current

38. - E8A07

What determines the PEP-to-average power ratio of a single-sideband phone signal?

Select	Answer
A	The frequency of the modulating signal
B	The characteristics of the modulating signal
C	The degree of carrier suppression
D	The amplifier gain

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	1/3
C	6000
D	3

40. - E8C02

What is the definition of symbol rate in a digital transmission?

Select	Answer
A	The number of characters carried per second by the station-to-station link
B	The rate at which the waveform of a transmitted signal changes to convey information
C	The duration of each bit in a message sent over the air
D	The number of control characters in a message packet

41. - E8D09

What is considered a good minimum IMD level for an idling PSK signal?

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

42. - E9A06

How does the beamwidth of an antenna vary as the gain is increased?

Select	Answer
A	It increases arithmetically
B	It increases geometrically
C	It is essentially unaffected
D	It decreases

43. - E9B11

What is a disadvantage of decreasing the number of wire segments in an antenna model below the guideline of 10 segments per half-wavelength?

Select	Answer
A	The computed feed point impedance may be incorrect
B	Ground conductivity will not be accurately modeled
C	The antenna will become mechanically unstable
D	The resulting design will favor radiation of harmonic energy

44. - E9C03

What is the radiation pattern of two 1/4 wavelength vertical antennas spaced a 1/2 wavelength apart and fed in phase?

Select	Answer
A	A Figure-8 end-fire along the axis of the array
B	A Figure-8 broadside to the axis of the array
C	Cardioid
D	Omni-directional

45. - E9D08

What happens as the Q of an antenna increases?

Select	Answer
A	More common-mode current is present on the feed line
B	SWR bandwidth decreases
C	SWR bandwidth increases
D	Gain is reduced

46. - E9E05

How must the driven element in a 3-element Yagi be tuned to use a hairpin matching system?

Select	Answer
A	The driven element reactance must be capacitive
B	The driven element radiation resistance must be higher than the characteristic impedance of the transmission line
C	The driven element reactance must be inductive
D	The driven element resonance must be lower than the operating frequency

47. - E9F08

What is the term for the ratio of the actual speed at which a signal travels through a transmission line to the speed of light in a vacuum?

Select	Answer
A	Surge impedance
B	Characteristic impedance
C	Velocity factor
D	Standing wave ratio

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	Prime axis
C	Polar axis
D	Impedance axis

49. - E9H07

Why is it advisable to use an RF attenuator on a receiver being used for direction finding?

Select	Answer
A	It compensates for the effects of an isotropic antenna, thereby improving directivity
B	It reduces loss of received signals caused by antenna pattern nulls, thereby increasing sensitivity
C	It narrows the bandwidth of the received signal to improve signal to noise ratio
D	It prevents receiver overload which could make it difficult to determine peaks or nulls

50. - E0A03

Which of the following would be a practical way to estimate whether the RF fields produced by an amateur radio station are within permissible MPE limits?

Select	Answer
A	Use a calibrated antenna analyzer
B	Use an antenna modeling program to calculate field strength at accessible locations
C	All of the choices are correct
D	Use a hand calculator plus Smith-chart equations to calculate the fields

Figure E6-5

Figure E9-3