Ham Extra License Practice Quiz
• Percentage: 0%; Correct: 0; Total: 0 of 50
E0A07: How may dangerous levels of carbon monoxide from an emergency generator be detected?
By the odor
Only with a carbon monoxide detector
Any ordinary smoke detector can be used
By the yellowish appearance of the gas
E1A08: If a station in a message forwarding system inadvertently forwards a message that is in violation of FCC rules, who is primarily accountable for the rules violation?
The control operator of the packet bulletin board station
The control operator of the originating station
The control operators of all the stations in the system
The control operators of all the stations in the system not authenticating the source from which they accept communications
E1B12: What is the highest modulation index permitted at the highest modulation frequency for angle modulation?
.5
1.0
2.0
3.0
E1C09: Which of these frequencies are available for an automatically controlled repeater operating below 30 MHz?
18.110 - 18.168 MHz
24.940 - 24.990 MHz
10.100 - 10.150 MHz
29.500 - 29.700 MHz
E1D10: Which amateur stations are eligible to be telecommand stations?
Any amateur station designated by NASA
Any amateur station so designated by the space station licensee, subject to the privileges of the class of operator license held by the control operator
Any amateur station so designated by the ITU
All of these choices are correct
E1E05: What is the minimum passing score on amateur operator license examinations?
Minimum passing score of 70%
Minimum passing score of 74%
Minimum passing score of 80%
Minimum passing score of 77%
E1F07: When may an amateur station send a message to a business?
When the total money involved does not exceed $25
When the control operator is employed by the FCC or another government agency
When transmitting international third-party communications
When neither the amateur nor his or her employer has a pecuniary interest in the communications
E2A11: What type of antenna can be used to minimize the effects of spin modulation and Faraday rotation?
A linearly polarized antenna
A circularly polarized antenna
An isotropic antenna
A log-periodic dipole array
E2B15: What signals SSTV receiving equipment to begin a new picture line?
Specific tone frequencies
Elapsed time
Specific tone amplitudes
A two-tone signal
E2C08: Why are received spread-spectrum signals resistant to interference?
Signals not using the spectrum-spreading algorithm are suppressed in the receiver
The high power used by a spread-spectrum transmitter keeps its signal from being easily overpowered
The receiver is always equipped with a digital blanker circuit
If interference is detected by the receiver it will signal the transmitter to change frequencies
E2D02: What is the definition of baud?
The number of data symbols transmitted per second
The number of characters transmitted per second
The number of characters transmitted per minute
The number of words transmitted per minute
E2E12: Which type of digital communication does not support keyboard-to-keyboard operation?
Winlink
RTTY
PSK31
MFSK
E3A06: What frequency range would you normally tune to find EME signals in the 2 meter band?
144.000 - 144.001 MHz
144.000 - 144.100 MHz
144.100 - 144.300 MHz
145.000 - 145.100 MHz
E3B09: At what time of day is gray-line propagation most likely to occur?
At sunrise and sunset
When the Sun is directly above the location of the transmitting station
When the Sun is directly overhead at the middle of the communications path between the two stations
When the Sun is directly above the location of the receiving station
E3C05: Which of the following describes selective fading?
Variability of signal strength with beam heading
Partial cancellation of some frequencies within the received pass band
Sideband inversion within the ionosphere
Degradation of signal strength due to backscatter
E4A10: Which of the following tests establishes that a silicon NPN junction transistor is biased on?
Measure base-to-emitter resistance with an ohmmeter; it should be approximately
Measure base-to-emitter resistance with an ohmmeter; it should be approximately 0.6 to 0.7 ohms
Measure base-to-emitter voltage with a voltmeter; it should be approximately
Measure base-to-emitter voltage with a voltmeter; it should be approximately
E4B11: How should a portable antenna analyzer be connected when measuring antenna resonance and feed point impedance?
Loosely couple the analyzer near the antenna base
Connect the analyzer via a high-impedance transformer to the antenna
Connect the antenna and a dummy load to the analyzer
Connect the antenna feed line directly to the analyzer's connector
E4C10: Which of the following is a desirable amount of selectivity for an amateur RTTY HF receiver?
100 Hz
300 Hz
6000 Hz
2400 Hz
E4D08: What causes intermodulation in an electronic circuit?
Too little gain
Lack of neutralization
Nonlinear circuits or devices
Positive feedback
E4E03: Which of the following signals might a receiver noise blanker be able to remove from desired signals?
Signals which are constant at all IF levels
Signals which appear across a wide bandwidth
Signals which appear at one IF but not another
Signals which have a sharply peaked frequency distribution
E5A17: What is the resonant frequency of a parallel RLC circuit if R is 47 ohms, L is 25 microhenrys and C is 10 picofarads?
10.1 MHz
63.2 MHz
10.1 kHz
63.2 kHz
E5B06: How long does it take for an initial charge of 800 V DC to decrease to 294 V DC in a 450-microfarad capacitor when a 1-megohm resistor is connected across it?
4.50 seconds
9 seconds
450 seconds
900 seconds
E5C03: In polar coordinates, what is the impedance of a network consisting of a 300-ohm-reactance capacitor, a 600-ohm-reactance inductor, and a 400-ohm resistor, all connected in series?
500 ohms at an angle of 37 degrees
900 ohms at an angle of 53 degrees
400 ohms at an angle of 0 degrees
1300 ohms at an angle of 180 degrees
E5D01: What is the result of skin effect?
As frequency increases, RF current flows in a thinner layer of the conductor, closer to the surface
As frequency decreases, RF current flows in a thinner layer of the conductor, closer to the surface
Thermal effects on the surface of the conductor increase the impedance
Thermal effects on the surface of the conductor decrease the impedance
E6A06: What is the beta of a bipolar junction transistor?
The frequency at which the current gain is reduced to 1
The change in collector current with respect to base current
The breakdown voltage of the base to collector junction
The switching speed of the transistor
E6B07: What is the failure mechanism when a junction diode fails due to excessive current?
Excessive inverse voltage
Excessive junction temperature
Insufficient forward voltage
Charge carrier depletion
E6C02: What logic state do the inputs of a TTL device assume if they are left open?
A logic-high state
A logic-low state
The device becomes randomized and will not provide consistent high or low-logic states
Open inputs on a TTL device are ignored
E6D09: What devices are commonly used as VHF and UHF parasitic suppressors at the input and output terminals of transistorized HF amplifiers?
Electrolytic capacitors
Butterworth filters
Ferrite beads
Steel-core toroids
E6E09: Which of the following must be done to insure that a crystal oscillator provides the frequency specified by the crystal manufacturer?
Provide the crystal with a specified parallel inductance
Provide the crystal with a specified parallel capacitance
Bias the crystal at a specified voltage
Bias the crystal at a specified current
E6F02: What happens to the conductivity of a photoconductive material when light shines on it?
It increases
It decreases
It stays the same
It becomes unstable
E7A14: What is a JK flip-flop?
A flip-flop similar to an RS except that it toggles when both J and K are high
A flip-flop utilizing low power, low temperature Joule-Kelvin devices
A flip-flop similar to a D flip-flop except that it triggers on the negative clock edge
A flip-flop originally developed in Japan and Korea which has very low power consumption
E7B02: What is a Class D amplifier?
A type of amplifier that uses switching technology to achieve high efficiency
A low power amplifier using a differential amplifier for improved linearity
An amplifier using drift-mode FETs for high efficiency
A frequency doubling amplifier
E7C05: Which filter type is described as having ripple in the passband and a sharp cutoff?
A Butterworth filter
An active LC filter
A passive op-amp filter
A Chebyshev filter
E7D10: What is the purpose of C3 in the circuit shown in Figure E7-3?
It prevents self-oscillation
It provides brute force filtering of the output
It provides fixed bias for Q1
It clips the peaks of the ripple
E7E01: Which of the following can be used to generate FM phone emissions?
A balanced modulator on the audio amplifier
A reactance modulator on the oscillator
A reactance modulator on the final amplifier
A balanced modulator on the oscillator
E7F04: What additional circuitry must be added to a 100-kHz crystal-controlled marker generator so as to provide markers at 50 and 25 kHz?
An emitter-follower
Two frequency multipliers
Two flip-flops
A voltage divider
E7G14: What is the typical input impedance of an integrated circuit op-amp?
100 ohms
1000 ohms
Very low
Very high
E7H10: What information is contained in the lookup table of a direct digital frequency synthesizer?
The phase relationship between a reference oscillator and the output waveform
The amplitude values that represent a sine-wave output
The phase relationship between a voltage-controlled oscillator and the output waveform
The synthesizer frequency limits and frequency values stored in the radio memories
E8A09: What type of waveform is produced by human speech?
Sinusoidal
Logarithmic
Irregular
Trapezoidal
E8B11: Which of the following describes frequency division multiplexing?
The transmitted signal jumps from band to band at a predetermined rate
Two or more information streams are merged into a "baseband", which then modulates the transmitter
The transmitted signal is divided into packets of information
Two or more information streams are merged into a digital combiner, which then pulse position modulates the transmitter
E8C01: Which one of the following digital codes consists of elements having unequal length?
ASCII
AX.25
Baudot
Morse code
E8D08: Which of the following best describes electromagnetic waves traveling in free space?
Electric and magnetic fields become aligned as they travel
The energy propagates through a medium with a high refractive index
The waves are reflected by the ionosphere and return to their source
Changing electric and magnetic fields propagate the energy
E9A01: Which of the following describes an isotropic antenna?
A grounded antenna used to measure earth conductivity
A horizontally polarized antenna used to compare Yagi antennas
A theoretical antenna used as a reference for antenna gain
A spacecraft antenna used to direct signals toward the earth
E9B03: In the antenna radiation pattern shown in Figure E9-1, what is the front-to-side ratio?
12 dB
14 dB
18 dB
24 dB
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?
A cardioid
A figure-8 end-fire along the axis of the array
A figure-8 broadside to the axis of the array
Omnidirectional
E9D14: Which of the following types of conductor would be best for minimizing losses in a station's RF ground system?
A resistive wire, such as a spark plug wire
A wide flat copper strap
A cable with 6 or 7 18-gauge conductors in parallel
A single 12 or 10-gauge stainless steel wire
E9E13: What is the purpose of a Wilkinson divider?
It divides the operating frequency of a transmitter signal so it can be used on a lower frequency band
It is used to feed high-impedance antennas from a low-impedance source
It divides power equally among multiple loads while preventing changes in one load from disturbing power flow to the others
It is used to feed low-impedance loads from a high-impedance source
E9F03: Why is the physical length of a coaxial cable transmission line shorter than its electrical length?
Skin effect is less pronounced in the coaxial cable
The characteristic impedance is higher in a parallel feed line
The surge impedance is higher in a parallel feed line
Electrical signals move more slowly in a coaxial cable than in air
E9G03: Which of the following is often determined using a Smith chart?
Beam headings and radiation patterns
Satellite azimuth and elevation bearings
Impedance and SWR values in transmission lines
Trigonometric functions
E9H07: Why is it advisable to use an RF attenuator on a receiver being used for direction finding?
It narrows the bandwidth of the received signal to improve signal to noise ratio
It compensates for the effects of an isotropic antenna, thereby improving directivity
It reduces loss of received signals caused by antenna pattern nulls, thereby increasing sensitivity
It prevents receiver overload which could make it difficult to determine peaks or nulls
