Grol Element 3 Modified 300

Front 1

The product of the readings of an AC voltmeter and AC ammeter is called:

Back 1

A. Apparent power.

Front 2

What is the basic unit of electrical power?

Back 2

B. Watt.

Front 3

What is the term used to express the amount of electrical energy stored in an electrostatic field?

Back 3

A. Joules

Front 4

What device is used to store electrical energy in an electrostatic field?

Back 4

C. Capacitor.

Front 5

What formula would determine the inductive reactance of a coil if frequency and coil inductance are known?

Back 5

B. X(sub L) = 2πfL

Front 6

What is the term for the out-of-phase power associated with inductors and capacitors?

Back 6

D. Reactive power.

Front 7

What determines the strength of the magnetic field around a conductor?

Back 7

D. The amount of current.

Front 8

What will produce a magnetic field?

Back 8

C. A current flowing through a conductor.

Front 9

The opposition to the creation of magnetic lines of force in a magnetic circuit is known as:

Back 9

D. Reluctance.

Front 10

Permeability is defined as:

Back 10

B. The ratio of magnetic flux density in a substance to the magnetizing force that produces it.

Front 11

What metal is usually employed as a sacrificial anode for corrosion control purposes?

Back 11

C. Zinc bar.

Front 12

What is the relative dielectric constant for air?

Back 12

A. 1

Front 13

Which metal object may be least affected by galvanic corrosion when submerged in seawater?

Back 13

D. Stainless steel propeller shaft.

Front 14

which of the 4 groups of metals listed below are the best low-resistance conductors?

Back 14

A. Gold, silver, and copper.

Front 15

How would you calculate the total capacitance of three capacitors in parallel?

Back 15

B. C(sub T) = C(sub 1) + C(sub 2) +C(sub 3)

Front 16

How might you reduce the inductance of an antenna coil?

Back 16

C. Reduce the number of turns.

Front 17

What are the two most commonly-used specifications for a junction diode?

Back 17

D. Maximum forward current and PIV (peak inverse voltage).

Front 18

MOSFETs are manufactured with THIS protective device built into their gate to protect the device from static charges and excessive voltages:

Back 18

C. Zener diode.

Front 19

What are the two basic types of junction field-effect transistors?

Back 19

A. N-channel and P-channel.

Front 20

An AC ammeter indicates:

Back 20

B. Effective (RMS) values of current.

Front 21

By what factor must the voltage of an AC circuit, as indicated on the scale of an AC voltmeter, be multiplied to obtain the peak voltage value?

Back 21

C. 1.414

Front 22

What is the RMS voltage of a common household electrical power outlet?

Back 22

D. 117-V AC

Front 23

What is the easiest voltage amplitude to measure by viewing a pure sine wave signal on an oscilloscope?

Back 23

A. Peak-to-peak.

Front 24

How many degrees are there in one complete sine wave cycle?

Back 24

D. 360 degrees.

Front 25

What type of wave is made up of sine waves at the fundamental frequency and all the harmonics?

Back 25

A. Sawtooth wave.

Front 26

What type of wave is characterized by a rise time significantly faster than the fall time (or vice versa)?

Back 26

C. Sawtooth wave.

Front 27

What is the term used to identify an AC voltage that would cause the same heating in a resistor as a corresponding value of DC voltage?

Back 27

C. Root mean square (RMS).

Front 28

What happens to reactive power in a circuit that has both inductors and capacitors?

Back 28

B. It alternates between magnetic and electric fields and is not dissipated.

Front 29

Halving the cross-sectional area of a conductor will:

Back 29

C. Double the resistance.

Front 30

What value of circuit resistance would be needed to obtain a full scale deflection on a 50 microamp DC meter with an applied voltage of 200 volts DC?

Back 30

A. 4 megohms

Front 31

Which of the following Ohms Law formulas is incorrect?

Back 31

B. I = R/E

Front 32

If a 100-ohm resistor is connected across 200 volts, what is the current through the resistor?

Back 32

A. 2 amperes

Front 33

A relay coil has 500 ohms resistance, and operates on 125 mA. What value of resistance should be connected in series with it to operate from 110 VDC?

Back 33

C. 380 ohms

Front 34

What is the maximum DC or RMS voltage that may be connected across a 20 watt, 2000 ohm resistor?

Back 34

C. 200 volts

Front 35

What is the voltage drop across R(1) if 10V source with R(1) 300 ohms in parallel with R(2) 200 ohms and R(3) 100 ohms?

Back 35

C. 5 volts

Front 36

What is the second harmonic of SSB frequency 4146 kHz?

Back 36

A. 8292 kHz

Front 37

What is the most the actual transmitter frequency could differ from a reading of 156,520,000 hertz on a frequency counter with a time base accuracy of +- 10 ppm?

Back 37

B. 1565.20 Hz

Front 38

What is the most the actual transmitter frequency could differ from a reading of 462,100,000 hertz on a frequency counter with a time base accuracy of +- 1.0 ppm?

Back 38

D. 462.1 Hz

Front 39

At pi/3 radians, what is the amplitude of a sine-wave having a peak value of 5 volts?

Back 39

D. +4.3 volts

Front 40

At 150 degrees, what is the amplitude of a sine-wave having a peak value of 5 volts?

Back 40

C. +2.5 volts

Front 41

At 240 degrees, what is the amplitude of a sine-wave having a peak value of 5 volts?

Back 41

A. -4.3 volts

Front 42

What is the equivalent to the root-mean-square value of an AC voltage?

Back 42

D. The DC voltage causing the same heating in a given resistor as the RMS AC voltage of the same value.

Front 43

What is the RMS value of a 340-volt-peak-to-peak pure sine?

Back 43

C. 120 volts AC

Front 44

In a circuit where the AC voltage and current are out of phase, how can the true power be determined?

Back 44

A. By multiplying the apparent power times the power factor.

Front 45

What does the power factor equal in an R-L circuit having a 45 degree phase angle between the voltage and the current?

Back 45

D. 0.707

Front 46

What does the power factor equal in an R-L circuit having a 30 degree phase angle between the voltage and the current?

Back 46

B. 0.866

Front 47

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

Back 47

B. One time constant.

Front 48

What is the meaning of the term "time constant of an RC circuit"? The time required to charge the capacitor in the circuit to:

Back 48

D. 63.2% of the supply voltage

Front 49

What is the term for the time required for the current in an RL circuit to build up to 63.2% of the maximum value?

Back 49

A. One time constant

Front 50

What is the meaning of the term "time constant of an RL circuit"? The time required for the:

Back 50

C. Current in the circuit to build up to 63.2% of the maximum value.

Front 51

After two time constants, the capacitor in an RC circuit is charged to what percentage of the supply voltage?

Back 51

C. 86.5%

Front 52

After two time constants, the capacitor in an RC circuit is discharged to what percentage of the starting voltage?

Back 52

B. 13.5%

Front 53

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

Back 53

D. 220 seconds

Front 54

What is the time constant of a circuit having a 220-microfarad capacitor and a 1-megohm resistor in parallel?

Back 54

A. 220 seconds

Front 55

In rectangular coordinates, what is the impedance of a network composed of a 10-microhenry inductor in series with a 40-ohm resistor, at 500 Mhz?

Back 55

A. 40+j31400

Front 56

In rectangular coordinates, what is the impedance of a network composed of a 1-millihenry inductor in series with a 200-ohm resistor, at 30 khz?

Back 56

B. 200+j188

Front 57

In rectangular coordinates, what is the impedance of a network composed of a 0.01-microfarad capacitor in parallel with a 300-ohm resistor, at 50 khz?

Back 57

C. 159-j150

Front 58

In rectangular coordinates, what is the impedance of a network composed of a 0.001-microfarad capacitor in series with a 400-ohm resistor, at 500 khz?

Back 58

D. 400-j318

Front 59

What is the impedance of a network composed of a 100-picofarad capacitor in parallel with a 4000-ohm resistor, at 500 KHz? Specify your answer in polar coordinates.

Back 59

D. 2490 ohms /-51.5 degrees

Front 60

In polar coordinates, what is the impedance of a network composed of a 100-ohm-reactance inductor in series with a 100-ohm resistor?

Back 60

B. 141 ohms /45 degrees

Front 61

Using the polar coordinate system, what visual representation would you get of a voltage in a sinewave circuit?

Back 61

D. The plot shows the magnitude and phase angle.

Front 62

A 1-watt, 10-volt Zener diode with the following characteristics: I(min) = 5mA; I(max) = 95 mA; and Z = 8 ohms, is to be used as part of a voltage regulator in a 20-V power supply. Approximately what size current-limiting resistor would be used to set its bias to the midpoint of its operating range?

Back 62

B. 200 ohms

Front 63

Given a power supply with a full load voltage of 200 volts and a regulation of 25%, what is the no load voltage?

Back 63

D. 250 volts.

Front 64

What is the conductance (G) of a circuit if 6 amperes of current flows when 12 volts DC is applied?

Back 64

B. 0.50 Siemens (mhos).

Front 65

What happens to the conductivity of photoconductive material when light shines on it?

Back 65

A. It increases.

Front 66

What is the description of an optoisolator?

Back 66

A. An LED and a photosensitive device.

Front 67

What happens to the conductivity of a photosensitive semiconductor junction when it is illuminated?

Back 67

B. The junction resistance decreases.

Front 68

What is the description of an optocoupler?

Back 68

C. An LED and a photosensitive device.

Front 69

What factors determine the capacitance of a capacitor?

Back 69

D. Distance between the plates and the dielectric constant of the material between the plates.

Front 70

In Figure 3C4, if a small variable capacitor were installed in place of the dashed line, it would?

Back 70

C. Decrease parasitic oscillations.

Front 71

What is the purpose of a coupling capacitor?

Back 71

A. It blocks direct current and passes alternating current.

Front 72

A capacitor is sometimes placed in series with the primary of a power transformer to:

Back 72

A. Improve the power factor.

Front 73

A transformer used to step up its input voltage must have:

Back 73

B. More turns of wire on its secondary than on its primary.

Front 74

A power transformer has a primary winding of 200 turns of #24 wire and a secondary winding consisting of 500 turns of the same size wire. When 20 volts are applied to the primary winding, the expected secondary voltage will be:

Back 74

D. 50 volts

Front 75

A switching electronic voltage regulator:

Back 75

C. Switches the control device on or off, with the duty cycle proportional to the line or load conditions.

Front 76

What device is usually used as a stable reference voltage in a linear voltage regulator?

Back 76

A. Zener Diode

Front 77

In a regulated power supply, what type of component will most likely be used to establish a reference voltage?

Back 77

D. Zener Diode

Front 78

How might two similar SCRs be connected to safely distribute the power load of a circuit?

Back 78

C. In parallel, reverse polarity.

Front 79

What are the three terminals of an SCR?

Back 79

A. Anode, cathode, and gate.

Front 80

What is the transistor called that is fabricated as two complementary SCRs in parallel with a common gate terminal?

Back 80

A. TRIAC

Front 81

What is one common use for PIN diodes?

Back 81

B. RF switch.

Front 82

What is a common use of a hot-carrier diode?

Back 82

D. VHF and UHF mixers and detectors.

Front 83

What type of semiconductor diode varies its internal capacitance as the voltage applied to its terminals varies?

Back 83

B. Varactor diode.

Front 84

What is the meaning of the term "alpha" with regard to bipolar transistors? The change of:

Back 84

D. Collector current with respect to emitter current.

Front 85

What are the elements of a unijunction transistor?

Back 85

A. Base 1, base 2 and emitter.

Front 86

What does it mean for a transistor to be fully saturated?

Back 86

A. The collector current is at its maximum value.

Front 87

A common base amplifier has:

Back 87

B. More voltage gain than common emitter or common collector.

Front 88

An emitter-follower amplifier has:

Back 88

D. More current gain than common emitter or common base.

Front 89

What type of bias is required for an LED to produce luminescence?

Back 89

B. Forward bias.

Front 90

What determines the visible color radiated by an LED junction?

Back 90

D. The materials used to construct the device.

Front 91

What is the approximate operating current of a light-emitting diode?

Back 91

A. 20 mA.

Front 92

An LED facing a photodiode in a light-tight enclosure is commonly known as a/an:

Back 92

A. Optoisolator.

Front 93

What describes a diode junction that is forward biased?

Back 93

C. It is a low impedance.

Front 94

Why are special precautions necessary in handling FET and CMOS devices?

Back 94

B. They are susceptible to damage from static charges.

Front 95

What is the piezoelectric effect?

Back 95

A. Mechanical vibration of a crystal by the application of a voltage.

Front 96

What is the approximate magnitude of the impedance of a parallel R-L-C circuit at resonance?

Back 96

A. Approximately equal to the circuit resistance.

Front 97

What is the approximate magnitude of the impedance of a series R-L-C circuit at resonance?

Back 97

B. Approximately equal to the circuit resistance.

Front 98

How could voltage be greater across reactances in series than the applied voltage?

Back 98

D. Resonance

Front 99

What is the characteristic of the current flow in a series R-L-C circuit at resonance?

Back 99

A. Maximum

Front 100

What is the characteristic of the current flow within the parallel elements in a parallel R-L-C circuit at resonance?

Back 100

B. Maximum

Front 101

Which of the following op-amp circuits is operated open-loop?

Back 101

D. Comparator.

Front 102

RF input to a mixer is 200 MHz and the local oscillator frequency is 150 MHz. What output would you expect to see at the iF output prior to any filtering?

Back 102

A. 50, 150, 200 and 350 MHz.

Front 103

What spectral impurity components might be generated by a phase-locked-loop synthesizer?

Back 103

C. Broadband noise.

Front 104

In a direct digital synthesizer, what are the unwanted components on its output?

Back 104

B. Spurs at discrete frequencies.

Front 105

What is the definition of a phase-lokced loop (PLL) circuit?

Back 105

D. A servo loop consisting of a phase detector, a low-pass filter and voltage-controlled oscillator.

Front 106

Given the combined DC input voltages, what would the output voltage be in the circuit shown in Figure 3D7?

Back 106

D. -5.5 V

Front 107

Which lamps would be lit in the circuit shown in Figure 3D8?

Back 107

C. 2, 3, 4, 7 and 8.

Front 108

What is the common power supply voltage for TTL series integrated circuits?

Back 108

D. 5 volts.

Front 109

Which of the following instruments would be best for checking a TTL logic circuit?

Back 109

D. Logic probe.

Front 110

What do the initials TTL stand for?

Back 110

B. Transistor-transistor logic.

Front 111

What is a characteristic of an AND gate?

Back 111

B. Produces a logic "1" at its output only if all inputs are logic "1".

Front 112

What is a characteristic of a NOT gate?

Back 112

B. Produces a logic "0" at its output when the input is logic "1" and vice versa.

Front 113

Which of the following logic gates will provide an active high out when both inputs are active high?

Back 113

C. AND

Front 114

In a negative-logic circuit, what level is used to represent a logic 0?

Back 114

D. High level.

Front 115

For the logic input levels shown in Figure 3E12, what are the logic levels of test points A, B and C in this circuit? (Assume positive logic.)

Back 115

B. A is low, B is high and C is high.

Front 116

For the logic input levels given in Figure 3E13, what are the logic levels of test points A, B and C in this circuit? (Assume positive logic.)

Back 116

C. A is high, B is high and C is high.

Front 117

In a positive-logic circuit, what level is used to represent a logic 1?

Back 117

A. High level

Front 118

What is a flip-flop circuit? A binary sequential logic element with ___ stable states.

Back 118

C. 2

Front 119

How many R-S flip-flops would be required to constrict an 8 bit storage register?

Back 119

C. 8

Front 120

An R-S flip-flop is capable of doing all of the following except:

Back 120

D. Operate in toggle mode with R-S inputs held constant and CLK initiated.

Front 121

What is an astable multivibrator?

Back 121

D. A circuit that alternates between two unstable states.

Front 122

What is a bistable multivibrator circuit commonly named?

Back 122

D. Flip-flop.

Front 123

What does the term "IO" mean within a microprocessor system?

Back 123

C. Input-output.

Front 124

How many individual memory cells would be contained in a memory IC that has 4 data bus input/output pins and 4 address pins for connection to the address bus?

Back 124

D. 64

Front 125

What is the name of the random-accessed semiconductor memory IC that must be refreshed periodically to maintain reliable data storage in its memory matrix?

Back 125

B. DRAM - Dynamic Random- Access Memory.

Front 126

Which of the following is not part of a MCU processor?

Back 126

D. Voltage Regulator

Front 127

In a microprocessor, what is the meaning of the term "ALU"?

Back 127

B. Arithmetical logic unit.

Front 128

What circuit interconnects the microprocessor with the memory and input/output system?

Back 128

C. Data bus line.

Front 129

What is the purpose of a prescaler circuit?

Back 129

D. Divides an HF signal so that a low-frequency counter can display the operating frequency.

Front 130

What does the term "BCD" mean?

Back 130

C. Binary coded decimal.

Front 131

What integrated circuit device converts digital signals to analog signals?

Back 131

D. DAC

Front 132

What is the limiting condition for sensitivity in a communications receiver?

Back 132

A. The noise floor of the receiver.

Front 133

What is the definition of the term "receiver desensitizing"?

Back 133

B. A reduction in receiver sensitivity because of a strong signal on a nearby frequency.

Front 134

What is the term used to refer to a reduction in receiver sensitivity caused by unwanted high-level adjacent channel signals?

Back 134

A. Desensitizing.

Front 135

What is the term for the ratio between the largest tolerable receiver input signal and the minimum discernible signal?

Back 135

D. Dynamic range.

Front 136

How can selectivity be achieved in the front-end circuitry of a communications receiver?

Back 136

D. By using a preselector.

Front 137

How much gain should be used in the RF amplifier stage of a receiver?

Back 137

A. Sufficient gain to allow weak signals to overcome noise generated in the first mixer stage.

Front 138

Too much gain in a VHF receiver front end could result in this:

Back 138

D. Susceptibility of intermodulation interference from nearby transmitters.

Front 139

What is the advantage of a GaAsFET preamplifier in a modern VHF radio receiver?

Back 139

C. High gain and low noise floor.

Front 140

Why is the Colpitts oscillator circuit commonly used in a VFO (variable frequency oscillator)?

Back 140

C. It is stable.

Front 141

What is the oscillator stage called in a frequency synthesizer?

Back 141

A. VCO

Front 142

In Figure 3F15, which block diagram symbol (labeled 1 through 4) is used to represent a local oscillator?

Back 142

B. 2

Front 143

What is the mixing process in a radio receiver?

Back 143

D. The combination of two signals to produce sum and difference frequencies.

Front 144

If a receiver mixes a 13.8 MHz VFO with a 14.255 MHz receive signal to produce a 455 kHz intermediate frequency signal, what type of interference will a 13.345 MHz signal produce in the receiver?

Back 144

B. An image response.

Front 145

What degree of selectivity is desirable in the IF circuitry of a wideband FM phone receiver?

Back 145

D. 15 kHz.

Front 146

Which one of these filters can be used in micro-miniature electronic circuits?

Back 146

B. Receiver SAW IF filter.

Front 147

What is the primary purpose of the first IF amplifier stage in a receiver?

Back 147

D. Selectivity.

Front 148

What parameter must be selected when designing an audio filter using an op-amp?

Back 148

A. Bandpass characteristics.

Front 149

What are the distinguishing features of a Chebyshev filter?

Back 149

C. It allows ripple in the passband.

Front 150

When would it be more desirable to use an m-derived filter over a constant-k filter?

Back 150

D. When you need more attenuation at a certain frequency that is too close to the cut-off frequency for a constant-k filter.

Front 151

Which statement is true regarding the filter output characteristics shown in Figure 3F16?

Back 151

D. A is a low pass curve and D is a band stop curve.

Front 152

What is an m-derived filter?

Back 152

D. A filter that uses a trap to attenuate undesired frequencies too near cutoff for a constant-k filter.

Front 153

What is an advantage of a constant-k filter?

Back 153

A. It has high attenuation of signals at frequencies far removed from the pass band.

Front 154

What are the distinguishing features of a Butterworth filter?

Back 154

C. It has a maximally flat response over its passband.

Front 155

What is a product detector?

Back 155

C. It uses a mixing process with a locally generated carrier.

Front 156

What is the process of detection in a radio diode detector circuit?

Back 156

C. Rectification and filtering of RF.

Front 157

In a CTCSS controlled FM receiver, the CTCSS tone is filtered out after the:

Back 157

D. Discriminator but before the audio section.

Front 158

What is the digital signal processing term for noise subtraction circuitry?

Back 158

A. Adaptive filtering and autocorrelation.

Front 159

What makes a Digital Coded Squelch work?

Back 159

D. Digital codes.

Front 160

What causes a squelch circuit to function?

Back 160

A. Presence of noise.

Front 161

How can ferrite beads be used to suppress ignition noise? Install them:

Back 161

C. Install them in the primary and secondary ignition leads.

Front 162

What is the term used to refer to the condition where the signals from a very strong station are superimposed on other signals being received?

Back 162

B. Cross-modulation interference.

Front 163

What is cross-modulation interference?

Back 163

C. Modulation from an unwanted signal heard in addition to the desired signal.

Front 164

What is the distinguishing feature of a Class A amplifier?

Back 164

B. Output for the entire 360 degrees of the signal cycle.

Front 165

Which class of amplifier has the highest linearity and least distortion?

Back 165

A. Class A.

Front 166

Which class of amplifier provides the highest efficiency?

Back 166

C. Class C.

Front 167

What class of amplifier is distinguished by the bias being set well beyond cutoff?

Back 167

B. Class C.

Front 168

The class C amplifier output is present for what portion of the input cycle?

Back 168

A. Less than 180 degrees.

Front 169

What is the approximate DC input power to a Class AB RF power amplifier stage in an unmodulated carrier transmitter when the PEP output power is 500 watts?

Back 169

D. 1000 watts.

Front 170

The class AB amplifier output is present for what portion of the input cycle?

Back 170

C. More than 180 but less than 360 degrees.

Front 171

What is the total bandwidth of a FM phone trnasmission having a 5 kHz deviation and a 3 kHz modulating frequency?

Back 171

D. 16 kHz.

Front 172

How does the modulation index of a phase-modulated emission vary with RF carrier frequency?

Back 172

A. It does not depend on the RF carrier frequency.

Front 173

What is a blanched modulator?

Back 173

B. A modulator that produces a double sideband, suppressed carrier signal.

Front 174

What is a pi-network?

Back 174

D. A networks consisting of one inductor and two capacitors or two inductors and one capacitor.

Front 175

What is the resonant frequency in an electrical circuit?

Back 175

A. The frequency at which capacitive reactance equals inductive reactance.

Front 176

What is a pi-L network?

Back 176

B. A network consisting of two inductors and two capacitors.

Front 177

What will occur when a non-linear amplifier is used with a single-sideband phone transmitter?

Back 177

D. Distortion.

Front 178

To produce a single-sideband suppressed carrier transmission it is necessary to ___ the carrier and to ___ the unwanted sideband.

Back 178

B. Cancel, filter.

Front 179

In a single-sideband phone signal, what determines the PEP-to-average power ratio?

Back 179

C. The speech characteristics.

Front 180

How can intermodulation interference between two transmitter in close proximity often be reduced or eliminated?

Back 180

B. By installing a terminated circulator or ferrite isolator in the feed line to the transmitter and duplexer.

Front 181

What is the name of the condition that occurs when the signals of two transmitters in close proximity mix together in one or both of their final amplifiers, and unwanted signals at the sum and difference frequencies of the original transmissions are generated?

Back 181

D. Intermodulation interference.

Front 182

how can even-order harmonics be reduced or prevented in transmitter amplifier design?

Back 182

C. By using a push-pull amplifier.

Front 183

The deviation ratio is the :

Back 183

B. Maximum carrier frequency deviation to the highest audio modulating frequency.

Front 184

What is the deviation ratio for an FM phone signal having a maximum frequency deviation of plus or minus 5 kHz and accepting a maximum modulation rate of 3 kHz?

Back 184

D. 1.66

Front 185

What is meant by the term odulation index?

Back 185

A. The ratio between the deviation of a frequency modulated signal and the modulating frequency.

Front 186

In Figure 3H17, the block labeled 4 would indicate that this schematic is most likely a/an:

Back 186

C. SSB radio transmitter.

Front 187

In Figure 3H17, which block diagram symbol (labeled 1 through 4) represents where audio intelligence is inserted?

Back 187

B. 2

Front 188

What kind of input signal could be used to test the amplitude linearity of a single-sideband phone transmitter while viewing the output on an oscilloscope?

Back 188

C. A two-tone audio-frequency sine wave.

Front 189

What type of signals are used to conduct an SSB two-tone test?

Back 189

B. Two non-harmonically related audio signals that are within the modulation band pass of the transmitter.

Front 190

In a pulse-width modulation system, what parameter does the modulating signal vary?

Back 190

B. Pulse duration.

Front 191

What is the name of the type of modulation in which the modulating signal varies the duration of the transmitted pulse?

Back 191

D. Pulse-width modulation.

Front 192

What is one way that voice is transmitted in a pulse-width modulation system?

Back 192

C. A standard pulse is varied in duration by an amount depending on the voice waveform at that instant.

Front 193

When a lead-acid storage battery is being charged, a harmful effect to humans is:

Back 193

D. Emission of hydrogen gas.

Front 194

A battery with a terminal voltage of 12.5 volts is to be trickle-charged at a 0.5 A rate. What resistance should be connected in series with the battery to charge it from a 110-V DC line?

Back 194

C. 195 ohms.

Front 195

What capacity in amperes does a storage battery need to be in order to operate a 50 watt transmitter for 6 hours? Assume a continuous trnasmitter load of 70% of the key-locked demand of 40 A, and an emergency light load of 1.5 A.

Back 195

B. 177 ampere-hours.

Front 196

The average fully-charged voltage of a lead-acid storage cell is:

Back 196

D. 2.06 volts.

Front 197

What current will flow in a 6 volt storage battery with an internal resistance of 0.01 ohms, when a 3-watt, 6-volt lamp is connected?

Back 197

B. 0.4995 amps.

Front 198

If a marine radiotelephone receiver uses 75 watts of power and a transmitter uses 325 watts, how long can they both operate before discharging a 50 ampere-hour 12 volt battery?

Back 198

C. 1 1/2 hours.

Front 199

A 6 volt battery with 1.2 ohms internal resistance is connected across two light bulbs in parallel whose resistance is 12 ohms each. What is the current flow?

Back 199

B. 0.83 amps.

Front 200

What occurs if the load is removed from an operating series DC motor?

Back 200

D. It will accelerate until it falls apart.

Front 201

What is the line current of a 7 horsepower motor operating on 120 volts at full load, a power factor or 0.8, and 95 efficient?

Back 201

D. 57.2 amps.

Front 202

A 3 horsepower, 100 V DC motor is 85% efficient when developing its rated output. What is the current?

Back 202

C. 26. 300 amps.

Front 203

The output of a separately-excited AC generator running at a constant speed can be controlled by:

Back 203

B. The amount of field current.

Front 204

Why is the value of the radiation resistance of an antenna important?

Back 204

A. Knowing the radiation resistance makes it possible to match impedances for maximum power transfer.

Front 205

A radio frequency device that allows RF energy to pass through in one direction with very little loss but absorbs RF power in the opposite direction is a:

Back 205

D. Isolator.

Front 206

What is meant by the term radiation resistance of an antenna?

Back 206

D. An equivalent resistance that would dissipate the same amount of power as that radiated from an antenna.

Front 207

What is the current flowing through a 52 ohm line with an input of 1,872 watts?

Back 207

B. 6 amps.

Front 208

Which of the following represents the best standing wave ratio (SWR)?

Back 208

A. 1:1.

Front 209

There is an improper impedance match between a 30 watt transmitter and the antenna, with 5 watts reflected. How much power is actually radiated?

Back 209

C. 25 watts.

Front 210

A vertical 1/4 wave antenna receives signals:

Back 210

D. Equally from all horizontal directions.

Front 211

The resonant frequency of a Hertz antenna can be lowered by:

Back 211

B. Placing an inductance in series with the antenna.

Front 212

An excited 1/2 wavelength antenna produces:

Back 212

C. Both electro-magnetic and electro-static fields.

Front 213

What is the meaning of the term velocity factor of a transmission line?

Back 213

B. The velocity of the wave on the transmission line divided by the velocity of light in a vacuum.

Front 214

What determines the velocity factor in a transmission line?

Back 214

C. Dielectrics in the line.

Front 215

Referred to the fundamental frequency, a shorted stub line attached to the transmission line to absorb even harmonics could have a wavelength of:

Back 215

C. 1/4 wavelength.

Front 216

What is the effective radiated power of a repeater with 50 watts transmitter power output, 4 dB feed line loss, 3 dB duplexer and circulator loss, and 6 dB antenna gain?

Back 216

B. 39.7 watts.

Front 217

What is the effective radiated power of a repeater with 75 watts transmitter power output, 5 dB feedline loss, 4 dB duplexer and circulator loss, and 6 dB antenna gain?

Back 217

A. 37.6 watts.

Front 218

What is the effective radiated power of a repeater with 50 watts transmitter power output, 5 dB feed line loss, 4 dB duplexer and circulator loss, and 7 dB antenna gain?

Back 218

C. 31.5 watts.

Front 219

What is the frequency range of the Distance Measuring Equipment (DME) used to indicate an aircraft's slant range distance to a selected ground-based navigation station?

Back 219

C. 962 MHz to 1213 MHz.

Front 220

the Distance Measuring Equipment (DME) measures the distance from the aircraft to the DME ground station. This is referred to as:

Back 220

B. The slant range.

Front 221

The Distance Meausring Equipment (DME) ground station has a built-in delay between reception of an interrogation and transmission of the reply to allow:

Back 221

C. Operation at close range.

Front 222

What is the main underlying operating principle of an aircraft's Distance Measuring Equipment (DME)?

Back 222

A. A measurable amount of time is required to send and receive a radio signal through the Earth's atmosphere.

Front 223

What is the frequency range of the ground-based Very-high-frequency Omnidirectional Range (VOR) stations used for aircraft navigation?

Back 223

D. 108.00 MHz to 117.95 MHz.

Front 224

What is the main underlying operating principle of the Very-high-frequency Omnidirectional Range (VOR) aircraft navigational system?

Back 224

C. A phase difference between two AC voltages may be used to determine an aircraft's azimuth position in relation to a selected VOR station.

Front 225

Which of the following is a requried compoent of an Instrument Landing System (ILS)?

Back 225

B. Localizer: shows aircraft deviation horizontally from center of runway.

Front 226

What type of antenna is used is an aircraft's Instrument Landing System (ILS) glideslope installation?

Back 226

C. A folded dipole reception antenna.

Front 227

Choose the only correct statement about the localizer beam system used by aircraft to find the centerline of a runway during an Instrument Landing System(ILS) approach to an airport. The localizer beam system:

Back 227

D. Produces two amplitude modulated antenna patterns; one pattern with an audio frequency of 90 Hz and one pattern with an audio frequency of 150 Hz, one left of the runway centerline and one right of the runway centerline.

Front 228

What is the frequency range of an aircraft's Automatic Direction Finding (ADF) equipment?

Back 228

A. 190 kHz to 1750 kHz

Front 229

What is meant by the term "night effect" when using an aircraft's Automatic Direction Finding(ADF) equipment? Night effect refers to the fact that:

Back 229

B. Non Directional Beacon (NDB) transmissions can bounce-off the Earth's ionosphere at night and be received at almost any direction.

Front 230

What type of encoding is used in an aircraft's mode C transponder transmission to a ground station of the Air Traffic Control RADAR Beacon System (ATCRBS)?

Back 230

B. Pulse position modulation

Front 231

What type of antenna pattern is radiated from a ground station phased-array directional antenna when transmitting the PPM pulses in a Mode S interrogation signal of an aircraft's Traffic alert and Collision Avoidance System (TCAS) installation?

Back 231

D. 1030 MHz directional pattern

Front 232

What type of antenna is used in an aircraft's Instrument Landing System (ILS) marker beacon installation?

Back 232

C. A balanced loop reception antenna

Front 233

What is the frequency range of an aircraft's Very High Frequency (VHF) communications?

Back 233

A. 118.000 MHz to 136.975 MHz (worldwide up to 151.975 MHz)

Front 234

Aircraft Emergency Locator Transmitters (ELT) operate on what frequencies?

Back 234

D. 121.5, 243, and 406 MHz

Front 235

Some aircraft and avionics equipment operates with a prime power line frequency of 400 Hz. What is the principle advantage of a higher line frequency?

Back 235

C. The magnetic devices in a 400 Hz power supply such as transformers, chokes and filters are smaller and lighter than those used in 60Hz power supplies.

Front 236

Typical airborne HF transmitters usually provide a nominal RF power output to the antenna of (blank) watts, compared with (blank) watts RF output from a typical VHF transmitter.

Back 236

D. 100, 20

Front 237

Before ground testing an aircraft RADAR, the operator should:

Back 237

A. Ensure that the area in front of the antenna is clear of other maintenance personnel to avoid radiation hazards.

Front 238

What is a 1/2 digit on a DMM?

Back 238

B. Partial extended accuracy on lower part of the range.

Front 239

A 50 microampere meter movement has an internal resistance of 2,000 ohms. What applied voltage is required to indicate half-scale defection?

Back 239

D. 0.05 volts

Front 240

What is the purpose of a series multiplier resistor used with a voltmeter?

Back 240

A. It is used to increase the voltage-indicating range of the voltmeter.

Front 241

What instrument may be used to verify proper radio antenna functioning?

Back 241

C. An SWR meter.

Front 242

How is a frequency counter used?

Back 242

D. To measure the time between events, or the frequency, which is the reciprocal of the time.

Front 243

On an analog wattmeter, what part of the scale is most accurate and how much does that accuracy extend to the rest of the reading scale?

Back 243

A. The accuracy is only at full scale, and that absolute number reading is carried through to the rest of the range. The upper 1/3 of the meter is the only truly calibrated part.

Front 244

What is used to decrease circuit loading when using an oscilloscope?

Back 244

B. 10:1 divider probe.

Front 245

An oscilloscope can be used to accomplish all of the following except:

Back 245

C. Measure velocity of light with the aid of a light emitting diode.

Front 246

What instrument is used to check the signal quality of a single-sideband radio transmission?

Back 246

D. Oscilloscope.

Front 247

A(n)_____and_______can be combined to measure the characteristics of transmission lines. Such an arrangement is known as a time-domain reflectometer (TDR).

Back 247

B. Oscilloscope, pulse generator.

Front 248

What does the vertical axis of a spectrum analyzer display?

Back 248

A. Amplitude.

Front 249

What instrument is most accurate when checking antennas and transmission lines at the operating frequency of the antenna?

Back 249

D. Frequency domain reflectometer.

Front 250

What instrument is commonly used by radio service technicians to monitor frequency, modulation, check receiver sensitivity, distortion, and to generate audio tones?

Back 250

C. Service monitor.

Front 251

Which of the following answers is true?

Back 251

B. The RF Power reading on a CDMA radio is not accurate on an analog power meter.

Front 252

What is a common method used to program radios without using a "weird" connection?

Back 252

C. Infra-red communications.

Front 253

What is the common method for determining the exact sensitivity specification of a receiver?

Back 253

A. Measure the recovered audio for 12 dB of SINAD.

Front 254

Which of the following is the preferred method of cleaning solder from plated-through circuit-board holes?

Back 254

B. Use a vacuum device.

Front 255

What is the proper way to cut plastic wire ties?

Back 255

D. With flush-cut diagonal pliers and cut flush.

Front 256

The ideal method of removing insulation from wire is:

Back 256

A. The thermal stripper.

Front 257

A "hot gas bonder" is used:

Back 257

B. FOR NON-CONTACT MELTING OF SOLDER.

Front 258

What color is the binder for pairs 51-75 in a 100-pair cable?

Back 258

D. Green

Front 259

What tolerance off of plumb should a single base station radio rack be installed?

Back 259

D. Just inside the bubble on a level.

Front 260

On a 150 watt marine SSB HF transceiver, what would be indicated by a steady output of 75 watts when keying the transmitter on?

Back 260

A. There is probably a defect in the system causing the carrier to be transmitted.

Front 261

The tachometer of a building's elevator circuit experiences interference caused by the radio system nearby. What is a common potential "fix" for the problem?

Back 261

B. Add a .01 µF capacitor across the motor/tachometer leads.

Front 262

How might an installer verify correct GPS sentence to marine DSC VHF radio?

Back 262

B. Look for latitude and longitude on the display.

Front 263

Name two types of spread spectrum systems used in most RF communications applications?

Back 263

C. Direct Sequence and Frequency Hopping.

Front 264

What is the term used to describe a spread spectrum communications system where the center frequency of a conventional carrier is altered many times per sec on in accordance with a pseudo-random list of channels?

Back 264

A. Frequency hopping.

Front 265

What is a CODEC?

Back 265

C. A coder/decoder IC or circuitry that converts a voice signal into a predetermined digital format for encrypted transmission.

Front 266

The GSM (Global System for Mobile Communications) uses what type of CODEC for digital mobile radio system communications?

Back 266

A. Regular-Pulse Excited (RPE)

Front 267

Which of the following codes has gained the widest acceptance for exchange of data from one computer to another?

Back 267

D. ASCII

Front 268

What CODEC is used in Phase 2 P25 radios?

Back 268

D. AMBE

Front 269

What does the DSP not do in a modern DSP radio?

Back 269

D. Control SWR

Front 270

Which statement best describes the code used for GDMSS-DSC transmissions?

Back 270

A. A 10 bit error code starting with bits of data followed by a 3 bit error correcting code.

Front 271

What is the cannel spacing used for VHF marine radio?

Back 271

D. 25 kHz.

Front 272

What VHF channel is assigned for distress and calling?

Back 272

B. 16

Front 273

Maximum allowable frequency deviation for VHF marine radios is:

Back 273

A. +/- 5 kHz.

Front 274

What is the reason for the USA-INT control or function?

Back 274

B. It changes some channels that are normally duplex channels into simplex channels.

Front 275

What is a common occurrence when voice-testing an SSB aboard a boat?

Back 275

B. Voltage panel indicator lamps may glow with each syllable.

Front 276

What might contribute to apparent low voltage on marine SSB transmitting?

Back 276

C. Blown black negative fuse.

Front 277

What type of wire connects an SSB automatic tuner to an insulated backstay?

Back 277

D. GTO-15 high-voltage cable.

Front 278

Which of the following statements concerning SITOR communications is true?

Back 278

D. Two-way communication with the coast radio station using FEC is not necessary to be able to receive the broadcasts.

Front 279

What causes the SART to begin a transmission?

Back 279

B. After being activated the SART responds to RADAR interrogation.

Front 280

How should the signal from a Search And Rescue Radar Transponder appear on a RADAR display?

Back 280

D. A series of 12 equally spaced dots.

Front 281

In which frequency band does a search and rescue transponder operate?

Back 281

A. 9 GHz

Front 282

Which of the following statements concerning satellite EPIRBs is true?

Back 282

A. Once activated, these EPIRBs transmit a signal for use in identifying the vessel and for determining the posit of the beacon.

Front 283

What is facsimile?

Back 283

C. The transmission of printed pictures for permanent display on paper.

Front 284

What would be the bandwidth of a good crystal lattice band-pass filter for weather facsimile HF (high frequency) reception?

Back 284

C. 1 kHz at -6 dB

Front 285

Which of the following statements about NAVTEX is true?

Back 285

A. Receives MSI broadcasts using SITOR-B or FEC mode.

Front 286

What data language is bi-directional, multi-transmitter, multi-receiver network?

Back 286

A. NMEA 2000

Front 287

How should shielding be grounded on an NMEA 0183 data line?

Back 287

B. Terminated to ground at the talker and unterminated at the listener.

Front 288

What might occur in NMEA 2000 network topology if one device in line should fail?

Back 288

D. There will be no interruption to all other devices.

Front 289

In an NMEA 2000 device, a load equivalence number (LEN) of 1 is equivalent to how much current consumption?

Back 289

A. 50 mA

Front 290

What is the normal range of pulse repetition rates?

Back 290

D. 500 to 2,000 pps

Front 291

What is the normal range of pulse widths?

Back 291

B. .05 µs to 1.0 µs

Front 292

Shipboard RADAR is most commonly operated in what band?

Back 292

C. SHF

Front 293

The pulse repetition rate (prr) of a RADAR refers to the :

Back 293

D. Pulse rate of the magnetron

Front 294

The ATR box:

Back 294

A. Prevents the received signal from entering the transmitter.

Front 295

What device can be used to determine the performance of a RADAR system at sea?

Back 295

A. Echo box

Front 296

What is the purpose of a synchro transmitter and receiver?

Back 296

C. Transmits the angular position of the antenna to the indicator unit.

Front 297

The component or circuit providing the transmitter output power for a RADAR system is the:

Back 297

D. Magnetron

Front 298

When a RADAR is being operated on the 6 mile range setting what is the most appropriate pulse width and pulse repetition rate?

Back 298

C. 0.25 µs PW and 1,000 pps

Front 299

When a RADAR is being operated on the 1.5 mile range setting, what is the most appropriate pulse width and pulse repetition rate?

Back 299

B. 0.05 µs PW and 2,000 pps

Front 300

How does the gain of a parabolic dish antenna change when the operating frequency is doubled?

Back 300

C. Gain increases 6 dB

Front 301

What type of antenna or pickup device is used to extract the RADAR signal from the wave guide?

Back 301

A. J-hook

Front 302

What happens to the beamwidth of an antenna as the gain is increased? The beamwidth:

Back 302

D. Decreases as the gain is increased.

Front 303

A common shipboard RADAR antenna is the:

Back 303

A. Slotted array

Front 304

The permanent magnetic field that surrounds a traveling-wave tube (TWT) is intended to:

Back 304

B. Prevent the electron beam from spreading

Front 305

In the term "ARPA RADAR," ARPA is the acronym for which of the following?

Back 305

A. Automatic RADAR Plotting Aid

Front 306

RADAR collision avoidance systems utilize inputs from each of the following except your ship's:

Back 306

C. Anemometer

Front 307

What is the orbiting altitude of the Iridium satellite communications system?

Back 307

D. 485 miles

Front 308

What frequency band is used by the Iridium system for telephone and messaging?

Back 308

B. 1616 - 1626 MHz

Front 309

What services are provided by the Iridium system?

Back 309

C. Digital voice and Data at 2.4 kbps

Front 310

Which of the following statements about the Iridium system is true?

Back 310

A. There are 48 spot beams per satellite with a footprint of 30 miles in diameter.

Front 311

What is the orbital altitude of INMARSAT Satellites?

Back 311

B. 22,177 miles

Front 312

When engaging in voice communications via an INMARSAT-B terminal, what techniques are used?

Back 312

A. CODECs are used to digitize the voice signal.

Front 313

Which of the following conditions can render INMARSAT-B communications impossible?

Back 313

D. All of the above.

A. An obstruction, such as a mast, causing disruption of the signal between the satellite and the SES antenna when the vessel is steering a certain course.
B. A satellite whose signal is on a low elevation, below the horizon.
C. Travel beyond the effective radius of the satellite.

Front 314

What is the best description for the INMARSAT-C system?

Back 314

B. It is a store-and-forward system that provides routine and distress communications.

Front 315

The INMARSAT mini-M system is a:

Back 315

D. Satellite system utilizing spot beams to provide for small craft communications.

Front 316

What statement best describes the INMARSAT-B services?

Back 316

A. Voice at 16 kbps, Fax at 14.4 kbps and high-speed Data at 64/54.

Front 317

How many GPS satellites are normally in operation?

Back 317

C. 24

Front 318

What best describes the GPS Satellites orbits?

Back 318

A. They are in six orbital planes equally spaced and inclined about 55 degrees to the equator.

Front 319

Compliance with MPE, or Maximum Permissible Exposure to RF levels (as defined in FCC Part 1, OET bulletin 65) for "controlled" environments, are averaged over (blank) minutes, while "uncontrolled" RF environments are averaged over (blank) minutes.

Back 319

A. 6, 30

Front 320

Sites having multiple transmitting antennas must include antennas with more than (blank) % of the maximum permissible power density exposure limit when evaluating RF site exposure.

Back 320

B. 5

Front 321

RF exposure from portable radio transceivers may be harmful to the eyes because:

Back 321

D. RF heating may cause cataracts.

Front 322

What is the purpose of not putting sharp corners on the ground leads within a building?

Back 322

C. Lightning will jump off of the ground lead because it is not able to make sharp bends.

Front 323

What class of fire is one that is caused by an electrical short circuit and what is the preferred substance used to extinguish that type of fire?

Back 323

C. FE30

Front 324

Do short-stub lightning protectors work at all frequencies?

Back 324

D. No, only at the tuned frequency band.

Front 325

What does E stand for in circuit power?

Back 325

Volts = Electro Motive Force

Front 326

What does I stand for in circuit power?

Back 326

Current (Amps) = Intensity of Current Flow

Front 327

What does R stand for in circuit power?

Back 327

Resistance = Ohms

Front 328

What does P stand for in circuit power?

Back 328

Watts = Power

Front 329

What does G stand for in circuit power?

Back 329

Conductance = Siemens or Mhos

(Opposite of Resistance)

Front 330

What does C stand for in circuit power?

Back 330

Capacitance = Farads = F

Front 331

What does L stand for in circuit power?

Back 331

Inductance = Henrys = H

Front 332

What does F stand for in circuit power?

Back 332

Frequency (cycles per second) = Hertz = Hz

Front 333

What does T stand for in circuit power?

Back 333

Time = Measured in Seconds = s

Front 334

What does RF stand for?

Back 334

Radio Frequency

Front 335

In a series circuit current (I) does what?

Back 335

Is the same through the whole circuilt.

Front 336

In a series circuit voltage (E) does what?

Back 336

It adds together

Front 337

In a parallel circuit current (I) does what?

Back 337

It adds together

Front 338

In a parallel circuit voltage (E) does what?

Back 338

It is the same in the entire circuit.