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Amateur Radio - Extra > E6 - CIRCUIT COMPONENTS [6 Exam Questions - 6 Groups] > Flashcards

E6 - CIRCUIT COMPONENTS [6 Exam Questions - 6 Groups] Flashcards

1
Q

In what application is gallium arsenide used as a semiconductor material in preference to germanium or silicon?

A. In high-current rectifier circuits

B. In high-power audio circuits

C. At microwave frequencies

D. At very low frequency RF circuits

A

C. At microwave frequencies

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2
Q

Which of the following semiconductor materials contains excess free electrons?

A. N-type

B. P-type

C. Bipolar

D. Insulated gate

A

A. N-type

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3
Q

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

A. Free neutrons

B. Free protons

C. Holes

D. Free electrons

A

C. Holes

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4
Q

What is the name given to an impurity atom that adds holes to a semiconductor crystal structure?

A. Insulator impurity

B. N-type impurity

C. Acceptor impurity

D. Donor impurity

A

C. Acceptor impurity

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5
Q

What is the alpha of a bipolar junction transistor?

A. The change of collector current with respect to base current

B. The change of base current with respect to collector current

C. The change of collector current with respect to emitter current

D. The change of collector current with respect to gate current

A

C. The change of collector current with respect to emitter current

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6
Q

What is the beta of a bipolar junction transistor?

A. The frequency at which the current gain is reduced to 1

B. The change in collector current with respect to base current

C. The breakdown voltage of the base to collector junction

D. The switching speed of the transistor

A

B. The change in collector current with respect to base current

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7
Q

In Figure E6-1, what is the schematic symbol for a PNP transistor?

A. 1

B. 2

C. 4

D. 5

A

A. 1

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8
Q

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

A. Corner frequency

B. Alpha rejection frequency

C. Beta cutoff frequency

D. Alpha cutoff frequency

A

D. Alpha cutoff frequency

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9
Q

What is a depletion-mode FET?

A. An FET that exhibits a current flow between source and drain when no gate voltage is applied

B. An FET that has no current flow between source and drain when no gate voltage is applied

C. Any FET without a channel

D. Any FET for which holes are the majority carriers

A

A. An FET that exhibits a current flow between source and drain when no gate voltage is applied

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10
Q

In Figure E6-2, what is the schematic symbol for an N-channel dual-gate MOSFET?

A. 2

B. 4

C. 5

D. 6

A

B. 4

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11
Q

In Figure E6-2, what is the schematic symbol for a P-channel junction FET?

A. 1

B. 2

C. 3

D. 6

A

A. 1

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12
Q

Why do many MOSFET devices have internally connected Zener diodes on the gates?

A. To provide a voltage reference for the correct amount of reverse-bias gate voltage

B. To protect the substrate from excessive voltages

C. To keep the gate voltage within specifications and prevent the device from overheating

D. To reduce the chance of the gate insulation being punctured by static discharges or excessive voltages

A

D. To reduce the chance of the gate insulation being punctured by static discharges or excessive voltages

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13
Q

What do the initials CMOS stand for?

A. Common Mode Oscillating System

B. Complementary Mica-Oxide Silicon

C. Complementary Metal-Oxide Semiconductor

D. Common Mode Organic Silicon

A

C. Complementary Metal-Oxide Semiconductor

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14
Q

How does DC input impedance at the gate of a field-effect transistor compare with the DC input impedance of a bipolar transistor?

A. They are both low impedance

B. An FET has low input impedance; a bipolar transistor has high input impedance

C. An FET has high input impedance; a bipolar transistor has low input impedance

D. They are both high impedance

A

C. An FET has high input impedance; a bipolar transistor has low input impedance

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15
Q

Which of the following semiconductor materials contains an excess of holes in the outer shell of electrons?

A. N-type

B. P-type

C. Superconductor-type

D. Bipolar-type

A

B. P-type

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16
Q

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

A. Holes

B. Free electrons

C. Free protons

D. Free neutrons

A

B. Free electrons

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17
Q

What are the names of the three terminals of a field-effect transistor?

A. Gate 1, gate 2, drain

B. Emitter, base, collector

C. Emitter, base 1, base 2

D. Gate, drain, source

A

D. Gate, drain, source

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18
Q

What is the most useful characteristic of a Zener diode?

A. A constant current drop under conditions of varying voltage

B. A constant voltage drop under conditions of varying current

C. A negative resistance region

D. An internal capacitance that varies with the applied voltage

A

B. A constant voltage drop under conditions of varying current

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19
Q

What is an important characteristic of a Schottky diode as compared to an ordinary silicon diode when used as a power supply rectifier?

A. Much higher reverse voltage breakdown

B. Controlled reverse avalanche voltage

C. Enhanced carrier retention time

D. Less forward voltage drop

A

D. Less forward voltage drop

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20
Q

What special type of diode is capable of both amplification and oscillation?

A. Point contact

B. Zener

C. Tunnel

D. Junction

A

C. Tunnel

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21
Q

What type of semiconductor device is designed for use as a voltage-controlled capacitor?

A. Varactor diode

B. Tunnel diode

C. Silicon-controlled rectifier

D. Zener diode

A

A. Varactor diode

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22
Q

What characteristic of a PIN diode makes it useful as an RF switch or attenuator?

A. Extremely high reverse breakdown voltage

B. Ability to dissipate large amounts of power

C. Reverse bias controls its forward voltage drop

D. A large region of intrinsic material

A

D. A large region of intrinsic material

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23
Q

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

A. As balanced mixers in FM generation

B. As a variable capacitance in an automatic frequency control circuit

C. As a constant voltage reference in a power supply

D. As a VHF / UHF mixer or detector

A

D. As a VHF / UHF mixer or detector

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24
Q

What is the failure mechanism when a junction diode fails due to excessive current?

A. Excessive inverse voltage

B. Excessive junction temperature

C. Insufficient forward voltage

D. Charge carrier depletion

A

B. Excessive junction temperature

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25
Q

Which of the following describes a type of semiconductor diode?

A. Metal-semiconductor junction

B. Electrolytic rectifier

C. CMOS-field effect

D. Thermionic emission diode

A

A. Metal-semiconductor junction

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26
Q

What is a common use for point contact diodes?

A. As a constant current source

B. As a constant voltage source

C. As an RF detector

D. As a high voltage rectifier

A

C. As an RF detector

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27
Q

In Figure E6-3, what is the schematic symbol for a light-emitting diode?

A. 1

B. 5

C. 6

D. 7

A

B. 5

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28
Q

What is used to control the attenuation of RF signals by a PIN diode?

A. Forward DC bias current

B. A sub-harmonic pump signal

C. Reverse voltage larger than the RF signal

D. Capacitance of an RF coupling capacitor

A

A. Forward DC bias current

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29
Q

What is one common use for PIN diodes?

A. As a constant current source

B. As a constant voltage source

C. As an RF switch

D. As a high voltage rectifier

A

C. As an RF switch

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30
Q

What type of bias is required for an LED to emit light?

A. Reverse bias

B. Forward bias

C. Zero bias

D. Inductive bias

A

B. Forward bias

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31
Q

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

A. 12 volts

B. 1.5 volts

C. 5 volts

D. 13.6 volts

A

C. 5 volts

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32
Q

What logic state do the inputs of a TTL device assume if they are left open?

A. A logic-high state

B. A logic-low state

C. The device becomes randomized and will not provide consistent high or low-logic states

D. Open inputs on a TTL device are ignored

A

A. A logic-high state

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33
Q

Which of the following describes tri-state logic?

A. Logic devices with 0, 1, and high impedance output states

B. Logic devices that utilize ternary math

C. Low power logic devices designed to operate at 3 volts

D. Proprietary logic devices manufactured by Tri-State Devices

A

A. Logic devices with 0, 1, and high impedance output states

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34
Q

Which of the following is the primary advantage of tri-state logic?

A. Low power consumption

B. Ability to connect many device outputs to a common bus

C. High speed operation

D. More efficient arithmetic operations

A

B. Ability to connect many device outputs to a common bus

35
Q

Which of the following is an advantage of CMOS logic devices over TTL devices?

A. Differential output capability

B. Lower distortion

C. Immune to damage from static discharge

D. Lower power consumption

A

D. Lower power consumption

36
Q

Why do CMOS digital integrated circuits have high immunity to noise on the input signal or power supply?

A. Larger bypass capacitors are used in CMOS circuit design

B. The input switching threshold is about two times the power supply voltage

C. The input switching threshold is about one-half the power supply voltage

D. Input signals are stronger

A

C. The input switching threshold is about one-half the power supply voltage

37
Q

In Figure E6-5, what is the schematic symbol for an AND gate?

A. 1

B. 2

C. 3

D. 4

A

A. 1

38
Q

In Figure E6-5, what is the schematic symbol for a NAND gate?

A. 1

B. 2

C. 3

D. 4

A

B. 2

39
Q

In Figure E6-5, what is the schematic symbol for an OR gate?

A. 2

B. 3

C. 4

D. 6

A

B. 3

40
Q

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

A. 1

B. 2

C. 3

D. 4

A

D. 4

41
Q

In Figure E6-5, what is the schematic symbol for the NOT operation (inverter)?

A. 2

B. 4

C. 5

D. 6

A

C. 5

42
Q

What is BiCMOS logic?

A. A logic device with two CMOS circuits per package

B. An FET logic family based on bimetallic semiconductors

C. A logic family based on bismuth CMOS devices

D. An integrated circuit logic family using both bipolar and CMOS transistors

A

D. An integrated circuit logic family using both bipolar and CMOS transistors

43
Q

Which of the following is an advantage of BiCMOS logic?

A. Its simplicity results in much less expensive devices than standard CMOS

B. It is totally immune to electrostatic damage

C. It has the high input impedance of CMOS and the low output impedance of bipolar transistors

D. All of these choices are correct

A

C. It has the high input impedance of CMOS and the low output impedance of bipolar transistors

44
Q

E6D01 (D)

What is cathode ray tube (CRT) persistence?

A. The time it takes for an image to appear after the electron beam is turned on

B. The relative brightness of the display under varying conditions of ambient light

C. The ability of the display to remain in focus under varying conditions

A

Optical

45
Q

Exceeding what design rating can cause a cathode ray tube (CRT) to generate X-rays?

A. The heater voltage

B. The anode voltage

C. The operating temperature

D. The operating frequency

A

B. The anode voltage

46
Q

Which of the following is true of a charge-coupled device (CCD)?

A. Its phase shift changes rapidly with frequency

B. It is a CMOS analog-to-digital converter

C. It samples an analog signal and passes it in stages from the input to the output

D. It is used in a battery charger circuit

A

C. It samples an analog signal and passes it in stages from the input to the output

47
Q

What function does a charge-coupled device (CCD) serve in a modern video camera?

A. It stores photogenerated charges as signals corresponding to pixels

B. It generates the horizontal pulses needed for electron beam scanning

C. It focuses the light used to produce a pattern of electrical charges corresponding to the image

D. It combines audio and video information to produce a composite RF signal

A

A. It stores photogenerated charges as signals corresponding to pixels

48
Q

What is a liquid-crystal display (LCD)?

A. A modern replacement for a quartz crystal oscillator which displays its fundamental frequency

B. A display using a crystalline liquid which, in conjunction with polarizing filters, becomes opaque when voltage is applied

C. A frequency-determining unit for a transmitter or receiver

D. A display that uses a glowing liquid to remain brightly lit in dim light

A

B. A display using a crystalline liquid which, in conjunction with polarizing filters, becomes opaque when voltage is applied

49
Q

What core material property determines the inductance of a toroidal inductor?

A. Thermal impedance

B. Resistance

C. Reactivity

D. Permeability

A

D. Permeability

50
Q

What is the usable frequency range of inductors that use toroidal cores, assuming a correct selection of core material for the frequency being used?

A. From a few kHz to no more than 30 MHz

B. From less than 20 Hz to approximately 300 MHz

C. From approximately 10 Hz to no more than 3000 kHz

D. From about 100 kHz to at least 1000 GHz

A

B. From less than 20 Hz to approximately 300 MHz

51
Q

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

A. Powdered-iron toroids generally have greater initial permeability

B. Powdered-iron toroids generally maintain their characteristics at higher currents

C. Powdered-iron toroids generally require fewer turns to produce a given inductance value

D. Powdered-iron toroids have higher power handling capacity

A

B. Powdered-iron toroids generally maintain their characteristics at higher currents

52
Q

What devices are commonly used as VHF and UHF parasitic suppressors at the input and output terminals of transistorized HF amplifiers?

A. Electrolytic capacitors

B. Butterworth filters

C. Ferrite beads

D. Steel-core toroids

A

C. Ferrite beads

53
Q

What is a primary advantage of using a toroidal core instead of a solenoidal core in an inductor?

A. Toroidal cores confine most of the magnetic field within the core material

B. Toroidal cores make it easier to couple the magnetic energy into other components

C. Toroidal cores exhibit greater hysteresis

D. Toroidal cores have lower Q characteristics

A

A. Toroidal cores confine most of the magnetic field within the core material

54
Q

How many turns will be required to produce a 1-mH inductor using a ferrite toroidal core that has an inductance index (A L) value of 523 millihenrys/1000 turns?

A. 2 turns

B. 4 turns

C. 43 turns

D. 229 turns

A

C. 43 turns

55
Q

How many turns will be required to produce a 5-microhenry inductor using a powdered-iron toroidal core that has an inductance index (A L) value of 40 microhenrys/100 turns?

A. 35 turns

B. 13 turns

C. 79 turns

D. 141 turns

A

A. 35 turns

56
Q

What type of CRT deflection is better when high-frequency waveforms are to be displayed on the screen?

A. Electromagnetic

B. Tubular

C. Radar

D. Electrostatic

A

D. Electrostatic

57
Q

Which is NOT true of a charge-coupled device (CCD)?

A. It uses a combination of analog and digital circuitry

B. It can be used to make an audio delay line

C. It is commonly used as an analog-to-digital converter

D. It samples and stores analog signals

A

C. It is commonly used as an analog-to-digital converter

58
Q

What is the principle advantage of liquid-crystal display (LCD) devices over other types of display devices?

A. They consume less power

B. They can display changes instantly

C. They are visible in all light conditions

D. They can be easily interchanged with other display devices

A

A. They consume less power

59
Q

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

A. Ferrite toroids generally have lower initial permeabilities

B. Ferrite toroids generally have better temperature stability

C. Ferrite toroids generally require fewer turns to produce a given inductance value

D. Ferrite toroids are easier to use with surface mount technology

A

C. Ferrite toroids generally require fewer turns to produce a given inductance value

60
Q

What is a crystal lattice filter?

A. A power supply filter made with interlaced quartz crystals

B. An audio filter made with four quartz crystals that resonate at 1-kHz intervals

C. A filter with wide bandwidth and shallow skirts made using quartz crystals

D. A filter with narrow bandwidth and steep skirts made using quartz crystals

A

D. A filter with narrow bandwidth and steep skirts made using quartz crystals

61
Q

Which of the following factors has the greatest effect in helping determine the bandwidth and response shape of a crystal ladder filter?

A. The relative frequencies of the individual crystals

B. The DC voltage applied to the quartz crystal

C. The gain of the RF stage preceding the filter

D. The amplitude of the signals passing through the filter

A

A. The relative frequencies of the individual crystals

62
Q

What is one aspect of the piezoelectric effect?

A. Physical deformation of a crystal by the application of a voltage

B. Mechanical deformation of a crystal by the application of a magnetic field

C. The generation of electrical energy by the application of light

D. Reversed conduction states when a P-N junction is exposed to light

A

A. Physical deformation of a crystal by the application of a voltage

63
Q

What is the most common input and output impedance of circuits that use MMICs?

A. 50 ohms

B. 300 ohms

C. 450 ohms

D. 10 ohms

A

A. 50 ohms

64
Q

Which of the following noise figure values is typical of a low-noise UHF preamplifier?

A. 2 dB

B. -10 dB

C. 44 dBm

D. -20 dBm

A

A. 2 dB

65
Q

What characteristics of the MMIC make it a popular choice for VHF through microwave circuits?

A. The ability to retrieve information from a single signal even in the presence of other strong signals.

B. Plate current that is controlled by a control grid

C. Nearly infinite gain, very high input impedance, and very low output impedance

D. Controlled gain, low noise figure, and constant input and output impedance over the specified frequency range

A

D. Controlled gain, low noise figure, and constant input and output impedance over the specified frequency range

66
Q

Which of the following techniques is typically used to construct a MMIC-based microwave amplifier?

A. Ground-plane construction

B. Microstrip construction

C. Point-to-point construction

D. Wave-soldering construction

A

B. Microstrip construction

67
Q

How is power-supply voltage normally furnished to the most common type of monolithic microwave integrated circuit (MMIC)?

A. Through a resistor and/or RF choke connected to the amplifier output lead

B. MMICs require no operating bias

C. Through a capacitor and RF choke connected to the amplifier input lead

D. Directly to the bias-voltage (VCC IN) lead

A

A. Through a resistor and/or RF choke connected to the amplifier output lead

68
Q

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

A. Provide the crystal with a specified parallel inductance

B. Provide the crystal with a specified parallel capacitance

C. Bias the crystal at a specified voltage

D. Bias the crystal at a specified current

A

B. Provide the crystal with a specified parallel capacitance

69
Q

What is the equivalent circuit of a quartz crystal?

A. Motional capacitance, motional inductance and loss resistance in series, with a shunt capacitance representing electrode and stray capacitance

B. Motional capacitance, motional inductance, loss resistance, and a capacitor representing electrode and stray capacitance all in parallel

C. Motional capacitance, motional inductance, loss resistance, and a capacitor represent electrode and stray capacitance all in series

D. Motional inductance and loss resistance in series, paralleled with motional capacitance and a capacitor representing electrode and stray capacitance

A

A. Motional capacitance, motional inductance and loss resistance in series, with a shunt capacitance representing electrode and stray capacitance

70
Q

Which of the following materials is likely to provide the highest frequency of operation when used in MMICs?

A. Silicon

B. Silicon nitride

C. Silicon dioxide

D. Gallium nitride

A

D. Gallium nitride

71
Q

What is a “Jones filter” as used as part of a HF receiver IF stage?

A. An automatic notch filter

B. A variable bandwidth crystal lattice filter

C. A special filter that emphasizes image responses

D. A filter that removes impulse noise

A

B. A variable bandwidth crystal lattice filter

72
Q

What is photoconductivity?

A. The conversion of photon energy to electromotive energy

B. The increased conductivity of an illuminated semiconductor

C. The conversion of electromotive energy to photon energy

D. The decreased conductivity of an illuminated semiconductor

A

B. The increased conductivity of an illuminated semiconductor

73
Q

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

A. It increases

B. It decreases

C. It stays the same

D. It becomes unstable

A

A. It increases

74
Q

What is the most common configuration of an optoisolator or optocoupler?

A. A lens and a photomultiplier

B. A frequency modulated helium-neon laser

C. An amplitude modulated helium-neon laser

D. An LED and a phototransistor

A

D. An LED and a phototransistor

75
Q

What is the photovoltaic effect?

A. The conversion of voltage to current when exposed to light

B. The conversion of light to electrical energy

C. The conversion of electrical energy to mechanical energy

D. The tendency of a battery to discharge when used outside

A

B. The conversion of light to electrical energy

76
Q

Which of the following describes an optical shaft encoder?

A. A device which detects rotation of a control by interrupting a light source with a patterned wheel

B. A device which measures the strength a beam of light using analog to digital conversion

C. A digital encryption device often used to encrypt spacecraft control signals

D. A device for generating RTTY signals by means of a rotating light source.

A

A. A device which detects rotation of a control by interrupting a light source with a patterned wheel

77
Q

Which of these materials is affected the most by photoconductivity?

A. A crystalline semiconductor

B. An ordinary metal

C. A heavy metal

D. A liquid semiconductor

A

A. A crystalline semiconductor

78
Q

What is a solid state relay?

A. A relay using transistors to drive the relay coil

B. A device that uses semiconductor devices to implement the functions of an electromechanical relay

C. A mechanical relay that latches in the on or off state each time it is pulsed

D. A passive delay line

A

B. A device that uses semiconductor devices to implement the functions of an electromechanical relay

79
Q

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

A. Optoisolators provide a low impedance link between a control circuit and a power circuit

B. Optoisolators provide impedance matching between the control circuit and power circuit

C. Optoisolators provide a very high degree of electrical isolation between a control circuit and the circuit being switched

D. Optoisolators eliminate the effects of reflected light in the control circuit

A

C. Optoisolators provide a very high degree of electrical isolation between a control circuit and the circuit being switched

80
Q

What is the efficiency of a photovoltaic cell?

A. The output RF power divided by the input dc power

B. The effective payback period

C. The open-circuit voltage divided by the short-circuit current under full illumination

D. The relative fraction of light that is converted to current

A

D. The relative fraction of light that is converted to current

81
Q

What is the most common type of photovoltaic cell used for electrical power generation?

A. Selenium

B. Silicon

C. Cadmium Sulfide

D. Copper oxide

A

B. Silicon

82
Q

Which of the following is the approximate open-circuit voltage produced by a fully-illuminated silicon�photovoltaic cell?

A. 0.1 V

B. 0.5 V

C. 1.5�V

D. 12 V

A

B. 0.5 V

83
Q

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

A. Protons

B. Photons

C. Electrons

D. Holes

A

C. Electrons

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