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. - E1A01

When using a transceiver that displays the carrier frequency of phone signals, which of the following displayed frequencies represents the highest frequency at which a properly adjusted USB emission will be totally within the band?

Select	Answer
A	1 kHz below the upper band edge
B	The exact upper band edge
C	3 kHz below the upper band edge
D	300 Hz below the upper band edge

2. - E1B05

What is the National Radio Quiet Zone?

Select	Answer
A	An area in New Mexico surrounding the White Sands Test Area
B	An area surrounding the National Radio Astronomy Observatory
C	An area in Puerto Rico surrounding the Arecibo Radio Telescope
D	An area in Florida surrounding Cape Canaveral

3. - E1C05

When may an automatically controlled station originate third party communications?

Select	Answer
A	When agreed upon by the sending or receiving station
B	Only when transmitting RTTY or data emissions
C	Never
D	When approved by the National Telecommunication and Information Administration

4. - E1D08

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

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

5. - E1E13

Which of these choices is an acceptable method for monitoring the applicants if a VEC opts to conduct an exam session remotely?

Select	Answer
A	Record the exam session on video tape for later review by the VE team
B	Use a real-time video link and the Internet to connect the exam session to the observing VEs
C	Have each applicant sign an affidavit stating that all session rules were followed
D	The exam proctor observes the applicants and reports any violations

6. - E1F09

Which of the following conditions apply when transmitting spread spectrum emission?

Select	Answer
A	A station transmitting SS emission must not cause harmful interference to other stations employing other authorized emissions
B	All of these choices are correct
C	The transmitting station must be in an area regulated by the FCC or in a country that permits SS emissions
D	The transmission must not be used to obscure the meaning of any communication

7. - E2A06

On what band would a satellite receive signals if it were operating in mode U/V?

Select	Answer
A	144 MHz - 146 MHz
B	435 MHz - 438 MHz
C	29.5 MHz - 29.7 MHz
D	50.0 MHz - 50.2 MHz

8. - E2B07

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

Select	Answer
A	Spectral Intensity
B	Luminance
C	Hue
D	Chroma

9. - E2C06

During a VHF/UHF contest, in which band segment would you expect to find the highest level of activity?

Select	Answer
A	At the top of each band, usually in a segment reserved for contests
B	In the middle of the band, usually 25 kHz above the national calling frequency
C	In the weak signal segment of the band, with most of the activity near the calling frequency
D	In the middle of each band, usually on the national calling frequency

10. - E2D05

Which of the following techniques is normally used by low Earth orbiting digital satellites to relay messages around the world?

Select	Answer
A	Node hopping
B	Multi-satellite relaying
C	Store-and-forward
D	Digipeating

11. - E2E10

Which of these digital modes has the narrowest bandwidth?

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

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 that circle the Earth
C	Waves with a rotating electric field
D	Waves produced by a loop antenna

13. - E3B04

What is meant by the terms extraordinary and ordinary waves?

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

14. - E3C01

What does the term ray tracing describe in regard to radio communications?

Select	Answer
A	Evaluating high voltage sources for X-Rays
B	Determining the radiation pattern from an array of antennas
C	Modeling a radio wave's path through the ionosphere
D	The process in which an electronic display presents a pattern

15. - E4A15

What is an advantage of a period-measuring frequency counter over a direct-count type?

Select	Answer
A	It provides improved resolution of low-frequency signals within a comparable time period
B	It can directly measure the modulation index of an FM transmitter
C	It does not require an expensive high-precision time base
D	It can run on battery power for remote measurements

16. - E4B08

Which of the following is a characteristic of a good DC voltmeter?

Select	Answer
A	Low impedance input
B	High reluctance input
C	Low reluctance input
D	High impedance input

17. - E4C03

What is the term for the blocking of one FM phone signal by another, stronger FM phone signal?

Select	Answer
A	Cross-modulation interference
B	Frequency discrimination
C	Capture effect
D	Desensitization

18. - E4D03

How can intermodulation interference between two repeaters occur?

Select	Answer
A	When the repeaters are in close proximity and the signals cause feedback in the final amplifier of one or both transmitters
B	When the signals from the transmitters are reflected out of phase from airplanes passing overhead
C	When the signals from the transmitters are reflected in phase from airplanes passing overhead
D	When the repeaters are in close proximity and the signals mix in the final amplifier of one or both transmitters

19. - E4E05

How can noise from an electric motor be suppressed?

Select	Answer
A	By installing a brute-force AC-line filter in series with the motor leads
B	By using a ground-fault current interrupter in the circuit used to power the motor
C	By installing a bypass capacitor in series with the motor leads
D	By installing a high pass filter in series with the motor's power leads

20. - E5A10

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

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

21. - E5B01

What is the term for the time required for the capacitor in an RC circuit to be charged to 63.2% of the applied voltage?

Select	Answer
A	An exponential rate of one
B	One exponential period
C	A time factor of one
D	One time constant

22. - E5C13

What coordinate system is often used to display the resistive, inductive, and/or capacitive reactance components of impedance?

Select	Answer
A	Elliptical coordinates
B	Maidenhead grid
C	Rectangular coordinates
D	Faraday grid

23. - E5D05

Which parasitic characteristic increases with conductor length?

Select	Answer
A	Permittivity
B	Permeability
C	Malleability
D	Inductance

24. - E6A16

What are the majority charge carriers in N-type semiconductor material?

Select	Answer
A	Holes
B	Free electrons
C	Free neutrons
D	Free protons

25. - E6B06

Which of the following is a common use of a hot-carrier diode?

Select	Answer
A	As a variable capacitance in an automatic frequency control circuit
B	As balanced mixers in FM generation
C	As a VHF/UHF mixer or detector
D	As a constant voltage reference in a power supply

26. - E6C14

What is the primary advantage of using a Programmable Gate Array (PGA) in a logic circuit?

Select	Answer
A	Complex logic functions can be created in a single integrated circuit
B	A PGA contains its own internal power supply
C	All of these choices are correct
D	Many similar gates are less expensive than a mixture of gate types

27. - E6D12

What is the definition of saturation in a ferrite core inductor?

Select	Answer
A	The inductor windings are over coupled
B	The ability of the inductor's core to store magnetic energy has been exceeded
C	The inductor's voltage rating is exceeded causing a flashover
D	Adjacent inductors become over-coupled

28. - E6E09

Which of the following component package types would be most suitable for use at frequencies above the HF range?

Select	Answer
A	Radial lead
B	Axial lead
C	TO-220
D	Surface mount

29. - E6F09

What is the efficiency of a photovoltaic cell?

Select	Answer
A	The effective payback period
B	The open-circuit voltage divided by the short-circuit current under full illumination
C	The output RF power divided by the input DC power
D	The relative fraction of light that is converted to current

30. - E7A07

What logical operation does a NAND gate perform?

Select	Answer
A	It produces logic "0" at its output only when all inputs are logic "0"
B	It produces logic "0" at its output if some but not all inputs are logic "1"
C	It produces logic "0" at its output only when all inputs are logic "1"
D	It produces logic "1" at its output only when all inputs are logic "1"

31. - E7B10

In Figure E7-1, what is the purpose of R1 and R2?

Select	Answer
A	Self bias
B	Feedback
C	Fixed bias
D	Load resistors

32. - E7C02

Which of the following is a property of a T-network with series capacitors and a parallel shunt inductor?

Select	Answer
A	It is a low-pass filter
B	It is a high-pass filter
C	It is a band-pass filter
D	It is a notch filter

33. - E7D16

When several electrolytic filter capacitors are connected in series to increase the operating voltage of a power supply filter circuit, why should resistors be connected across each capacitor?

Select	Answer
A	All of these choices are correct
B	To provide a minimum load current to reduce voltage excursions at light loads
C	To provide a safety bleeder to discharge the capacitors when the supply is off
D	To equalize, as much as possible, the voltage drop across each capacitor

34. - E7E04

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

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

35. - E7F16

How might the sampling rate of an existing digital signal be adjusted by a factor of 3/4?

Select	Answer
A	Change the gain by a factor of 3/4
B	Multiply each sample value by a factor of 3/4
C	Interpolate by a factor of three, then decimate by a factor of four
D	Add 3 to each input value and subtract 4 from each output value

36. - E7G02

What is the effect of ringing in a filter?

Select	Answer
A	Undesired oscillations added to the desired signal
B	A reduction in high frequency response
C	Partial cancellation of the signal over a range of frequencies
D	An echo caused by a long time delay

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

38. - E8A04

What is "dither" with respect to analog to digital converters?

Select	Answer
A	An error caused by irregular quantization step size
B	A small amount of noise added to the input signal to allow more precise representation of a signal over time
C	An abnormal condition where the converter cannot settle on a value to represent the signal
D	A method of decimation by randomly skipping samples

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	1000
B	3000
C	0.3
D	3

40. - E8C01

How is Forward Error Correction implemented?

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

41. - E8D07

What is a common cause of overmodulation of AFSK signals?

Select	Answer
A	Bit errors in the modem
B	Excessive transmit audio levels
C	Excessive numbers of retries
D	Ground loops

42. - E9A08

What is meant by antenna bandwidth?

Select	Answer
A	The frequency range over which an antenna satisfies a performance requirement
B	Antenna length divided by the number of elements
C	The angle formed between two imaginary lines drawn through the element ends
D	The angle between the half-power radiation points

43. - E9B13

What does the abbreviation NEC stand for when applied to antenna modeling programs?

Select	Answer
A	Next Element Comparison
B	Numeric Electrical Computation
C	Numerical Electromagnetic Code
D	National Electrical Code

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

45. - E9D05

What is a disadvantage of using a multiband trapped antenna?

Select	Answer
A	It is too sharply directional at lower frequencies
B	It must be neutralized
C	It radiates the harmonics and fundamental equally well
D	It might radiate harmonics

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

47. - E9F07

How does ladder line compare to small-diameter coaxial cable such as RG-58 at 50 MHz?

Select	Answer
A	Lower loss
B	Smaller reflection coefficient
C	Lower velocity factor
D	Higher SWR

48. - E9G11

How are the wavelength scales on a Smith chart calibrated?

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

49. - E9H10

How can the output voltage of a multiple turn receiving loop antenna be increased?

Select	Answer
A	By reducing the permeability of the loop shield
B	By winding adjacent turns in opposing directions
C	By increasing the number of wire turns in the loop and reducing the area of the loop structure
D	By increasing either the number of wire turns in the loop or the area of the loop structure or both

50. - E0A07

How may dangerous levels of carbon monoxide from an emergency generator be detected?

Select	Answer
A	By the yellowish appearance of the gas
B	By the odor
C	Only with a carbon monoxide detector
D	Any ordinary smoke detector can be used

Figure E7-1