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

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1. - E0A06

Why are there separate electric (E) and magnetic (H) field MPE limits?

Select	Answer
A	E field and H field radiation intensity peaks can occur at different locations
B	The body reacts to electromagnetic radiation from both the E and H fields
C	All these choices are correct
D	Ground reflections and scattering make the field strength vary with location

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

3. - E1B11

What does PRB-1 require of regulations affecting amateur radio?

Select	Answer
A	Amateur radio operations must be permitted in any private residence
B	No limitations may be placed on antenna size or placement
C	Reasonable accommodations of amateur radio must be made
D	Use of wireless devices in a vehicle is exempt from regulation

4. - E1C01

What is the maximum bandwidth for a data emission on 60 meters?

Select	Answer
A	170 Hz
B	2.8 kHz
C	60 Hz
D	1.5 kHz

5. - E1D08

Which VHF amateur bands have frequencies authorized for space stations?

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

6. - E1E04

Which of the following best describes the Volunteer Examiner accreditation process?

Select	Answer
A	Each General, Advanced and Amateur Extra Class operator is automatically accredited as a VE when the license is granted
B	The prospective VE obtains accreditation from the FCC
C	The amateur operator applying must pass a VE examination administered by the FCC Enforcement Bureau
D	The procedure by which a VEC confirms that the VE applicant meets FCC requirements to serve as an examiner

7. - E1F01

On what frequencies are spread spectrum transmissions permitted?

Select	Answer
A	Only on amateur frequencies above 420 MHz
B	Only on amateur frequencies above 50 MHz
C	Only on amateur frequencies above 222 MHz
D	Only on amateur frequencies above 144 MHz

8. - E2A01

What is the direction of an ascending pass for an amateur satellite?

Select	Answer
A	From south to north
B	From west to east
C	From east to west
D	From north to south

9. - E2B12

What signals SSTV receiving software to begin a new picture line?

Select	Answer
A	Elapsed time
B	Specific tone frequencies
C	Specific tone amplitudes
D	A two-tone signal

10. - E2C05

What is the function of a DX QSL Manager?

Select	Answer
A	To allocate frequencies for DXpeditions
B	To run a net to allow many stations to contact a rare DX station
C	To relay calls to and from a DX station
D	To handle the receiving and sending of confirmation cards for a DX station

11. - E2D08

What type of packet frame is used to transmit APRS beacon data?

Select	Answer
A	Connect
B	Disconnect
C	Acknowledgement
D	Unnumbered Information

12. - E2E03

How is the timing of FT4 contacts organized?

Select	Answer
A	Stations take turns on alternate days
B	By exchanging ACK/NAK packets
C	Alternating transmissions at 7.5 second intervals
D	It depends on the lunar phase

13. - E3A05

Tropospheric propagation of microwave signals often occurs in association with what phenomenon?

Select	Answer
A	Lightning discharges
B	Warm and cold fronts
C	Grayline
D	Sprites and jets

14. - E3B02

What is the approximate maximum range for signals using transequatorial propagation?

Select	Answer
A	7500 miles
B	1000 miles
C	5000 miles
D	2500 miles

15. - E3C01

What does the radio communication term "ray tracing" describe?

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

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	Amount of memory
D	Sampling rate of the analog-to-digital converter

17. - E4B01

Which of the following factors most affects the accuracy of a frequency counter?

Select	Answer
A	Temperature coefficient of the logic
B	Time base accuracy
C	Decade divider accuracy
D	Input attenuator accuracy

18. - E4C15

What is reciprocal mixing?

Select	Answer
A	In-phase signals cancelling in a mixer resulting in loss of receiver sensitivity
B	Two digital signals combining from alternate time slots
C	Two out-of-band signals mixing to generate an in-band spurious signal
D	Local oscillator phase noise mixing with adjacent strong signals to create interference to desired signals

19. - E4D05

What transmitter frequencies would cause an intermodulation-product signal in a receiver tuned to 146.70 MHz when a nearby station transmits on 146.52 MHz?

Select	Answer
A	146.10 MHz and 147.30 MHz
B	146.88 MHz and 146.34 MHz
C	173.35 MHz and 139.40 MHz
D	146.34 MHz and 146.61 MHz

20. - E4E08

What current flows equally on all conductors of an unshielded multi-conductor cable?

Select	Answer
A	Return current
B	Common-mode current
C	Reactive current only
D	Differential-mode current

21. - E5A09

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

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

22. - E5B04

What is the time constant of a circuit having two 220-microfarad capacitors and two 1-megohm resistors, all in parallel?

Select	Answer
A	440 seconds
B	110 seconds
C	55 seconds
D	220 seconds

23. - E5C02

How are impedances described in polar coordinates?

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

24. - E5D10

How can the true power be determined in an AC circuit where the voltage and current are out of phase?

Select	Answer
A	By multiplying the reactive power by the power factor
B	By dividing the apparent power by the power factor
C	By multiplying the apparent power by the power factor
D	By dividing the reactive power by the power factor

25. - E6A05

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	They are both low impedance
B	An FET has lower input impedance
C	An FET has higher input impedance
D	They are both high impedance

26. - E6B03

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

27. - E6C03

What is tri-state logic?

Select	Answer
A	Low-power logic devices designed to operate at 3 volts
B	Logic devices with 0, 1, and high-impedance output states
C	Proprietary logic devices manufactured by Tri-State Devices
D	Logic devices that utilize ternary math

28. - E6D11

Which type of core material decreases inductance when inserted into a coil?

Select	Answer
A	Ceramic
B	Brass
C	Powdered iron
D	Ferrite

29. - E6E09

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

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

30. - E6F08

Why are optoisolators often used in conjunction with solid-state circuits when switching 120 VAC?

Select	Answer
A	Optoisolators provide a very high degree of electrical isolation between a control circuit and the circuit being switched
B	Optoisolators eliminate the effects of reflected light in the control circuit
C	Optoisolators provide a low impedance link between a control circuit and a power circuit
D	Optoisolators provide impedance matching between the control circuit and power circuit

31. - E7A07

What logical operation does a NAND gate perform?

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

32. - E7B18

What is a characteristic of a grounded-grid amplifier?

Select	Answer
A	Low bandwidth
B	Low input impedance
C	High filament voltage
D	High power gain

33. - 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 band-pass filter
B	It is a low-pass filter
C	It is a notch filter
D	It is a high-pass filter

34. - E7D13

What is the equation for calculating power dissipated by a series linear voltage regulator?

Select	Answer
A	Output voltage multiplied by output current
B	Voltage difference from input to output multiplied by output current
C	Input voltage divided by output current
D	Input voltage multiplied by input current

35. - E7E01

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

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

36. - E7F13

What is the function of taps in a digital signal processing filter?

Select	Answer
A	Select the point at which baseband signals are generated
B	Provide incremental signal delays for filter algorithms
C	Provide access for debugging software
D	To reduce excess signal pressure levels

37. - E7G06

What is the gain-bandwidth of an operational amplifier?

Select	Answer
A	The frequency at which the open-loop gain of the amplifier equals one
B	The maximum frequency for a filter circuit using that type of amplifier
C	The gain of the amplifier at a filter's cutoff frequency
D	The frequency at which the amplifier's offset voltage is zero

38. - E7H09

What type of frequency synthesizer circuit uses a phase accumulator, lookup table, digital to analog converter, and a low-pass anti-alias filter?

Select	Answer
A	A hybrid synthesizer
B	A diode-switching matrix synthesizer
C	A phase-locked loop synthesizer
D	A direct digital synthesizer

39. - E8A01

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

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

40. - E8B01

What is the modulation index of an FM signal?

Select	Answer
A	The type of modulation used by the transmitter
B	The ratio of frequency deviation to modulating signal frequency
C	The bandwidth of the transmitted signal divided by the modulating signal frequency
D	The ratio of modulating signal amplitude to frequency deviation

41. - E8C09

Which digital code allows only one bit to change between sequential code values?

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

42. - 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

43. - E9A01

What is an isotropic antenna?

Select	Answer
A	A theoretical, omnidirectional antenna used as a reference for antenna gain
B	A horizontally polarized antenna used to compare Yagi antennas
C	A spacecraft antenna used to direct signals toward Earth
D	A grounded antenna used to measure Earth conductivity

44. - E9B06

What is the elevation angle of peak response in the antenna radiation pattern shown in Figure E9-2?

Select	Answer
A	45 degrees
B	7.5 degrees
C	75 degrees
D	25 degrees

45. - 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 vertical angle increases
D	The lobes become more perpendicular to the wire

46. - E9D12

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

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

47. - E9E04

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

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

48. - E9F07

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

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

49. - E9G04

What are the two families of circles and arcs that make up a Smith chart?

Select	Answer
A	Voltage and impedance
B	Resistance and reactance
C	Resistance and voltage
D	Reactance and voltage

50. - E9H04

What is an advantage of placing a grounded electrostatic shield around a small loop direction-finding antenna?

Select	Answer
A	It increases signal strength by providing a better match to the feed line
B	It eliminates unbalanced capacitive coupling to the surroundings, improving the nulls
C	It adds capacitive loading, increasing the bandwidth of the antenna
D	It eliminates tracking errors caused by strong out-of-band signals

Figure E9-2