Ekectronic Devices 6- Comms To Linear Digital IC Flashcards by XYRA Unknown

An AM demodulator can be implemented with a linear multiplier followed by a ________ filter.
low-pass
high-pass
band-pass
band-stop

low-pass

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The intermediate frequency in a standard AM receiver is
455 Hz.
455 kHz.
4.55 MHz.
none of the above

455 kHz.

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In order for a light ray to propagate along a fiber-optic cable, what must the relationship be between the angle of incidence and the critical angle?
θi > θc
θi < θc
θi = θc
none of the above

θi > θc

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Light may be propagated along a fiber-optic cable in which of the following modes?
multimode step index
single-mode step index
multimode graded index
all of the above

all of the above

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In AM, the carrier is changed by a modulating signal. What parameter of the carrier is changed?
amplitude
frequency
pulse width
phase

amplitude

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The output spectrum of a ________ modulator includes upper-side and lower-side frequencies and the carrier frequency.
balanced
standard amplitude
none of the above

standard amplitude

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Amplitude modulation is a ________ process.
multiplication
division
sum/difference

multiplication

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What does VCO stand for?
Visually-Controlled Organization
Voltage-Controlled Oscillator
Voltage-Centered Oscilloscope

Voltage-Controlled Oscillator

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A phase-locked loop (PLL) is a feedback circuit consisting of a
phase detector.
low-pass filter.
VCO.
all of the above

all of the above

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If a 1 MHz carrier is amplitude modulated with a 5 kHz audio signal, the upper-side frequency is ________ kHz.
1005
1000
995
none of the above

1005

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Which of the following areas is (are) an application of infrared-emitting diodes?
Intrusion alarms
Shaft encoders
Paper-tape readers
All of the above

All of the above

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Schottky diodes are very effective at frequencies approaching ________.
20 GHz
10 MHz
100 MHz
1 MHz

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What is the voltage drop across Schottky diodes?
0 V to 0.2 V
0.7 V to 0.8 V
0.8 V to 1.0 V
1.0 V to 1.5 V

0 V to 0.2 V

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In which region is the operating point stable in tunnel diodes?
Negative-resistance
Positive-resistance
Both negative- and positive-resistance
Neither negative- nor positive-resistance

Positive-resistance

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What is the range of the varying capacitor CT in varactor diodes?
0 pF to 5 pF
2 pF to 10 pF
2 F to 100 F
2 pF to 100 pF

2 pF to 100 pF

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What is the maximum temperature limit for liquid-crystal displays (LCDs)?
10ºC
30ºC
60ºC
100ºC

60ºC

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Which of the following diodes is limited to the reverse-bias region in its region of operation?
Schottky
Tunnel
Photodiode
Rectifier

Photodiode

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The majority of power diodes are constructed using ________.
molybdenum
platinum
tungsten
silicon

silicon

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Which of the following is (are) diodes?
Schottky
Varactor
Tunnel
All of the above

All of the above

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What is the limit of peak current IP in tunnel diodes?
A few microamperes to several hundred amperes
A few microamperes to several amperes
A few microamperes to several milliamperes
A few microamperes to several hundred microamperes

A few microamperes to several hundred amperes

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What is the response time of LCDs?
Less than 100 ns
50 ms
100 ms to 300 ms
400 ms

100 ms to 300 ms

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What is the typical level of change in resistance per degree change in temperature?
1% to 2%
3% to 5%
7% to 10%
10% to 25%

3% to 5%

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What is the maximum peak voltage for tunnel diodes?
50 mV
100 mV
250 mV
600 mV

600 mV

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Which of the following semiconductor materials is (are) used for manufacturing solar cells?
Gallium arsenide
Indium arsenide
Cadmium sulfide
All of the above

All of the above

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Which of the following semiconductor materials is (are) used in the manufacturing of tunnel diodes? Germanium Gallium Both germanium and gallium arsenide Silicon

Both germanium and gallium arsenide

What is the power density received from the sun at sea level? 10 mW/cm2 100 mW/cm2 500 mW/cm2 1 W/cm2

100 mW/cm2

The varicap diode has a transition capacitance sensitive to the applied reverse-bias potential that is a maximum at zero volts and decreases ________ with increasing reverse-bias potentials. logarithmically parabolically exponentially

exponentially

For a 50-A unit, the PIV of the Schottky is about ________ compared to 150 V for the p-n junction variety. 25 50 75 100

What metal(s) is(are) used in the construction of Schottky diodes? Molybdenum Platinum Tungsten Silicon Any of the above

Any of the above

Which of the following metals is (are) used in the fabrication of Schottky diodes? Molybdenum Platinum Tungsten All of the above

All of the above

What is the resistance of thermistors at boiling temperature (100ºC)? 5 k 1 k 100 1

100

Which of the following areas is (are) applications of varactor diodes? FM modulators Automatic-frequency control devices Adjustable bandpass filters All of the above

All of the above

Which of the following materials is (are) used in the manufacturing of thermistors? Ge Si A mixture of oxides of cobalt, nickel, strontium, or manganese All of the above

All of the above

What is the ratio IP / IV for gallium arsenide? 1:1 5:1 10:1 20:1

20:1

What is the response time of light-emitting diodes (LEDs)? Less than 100 ns 50 ms 100 ms to 300 ms 400 ms

Less than 100 ns

What type of temperature coefficient do thermistors have? Positive Negative Either positive or negative None of the above

Either positive or negative

Which of the following diodes has a negative-resistance region? Schottky Varactor Tunnel Power

Tunnel

The tuning diode is a ________-dependent, variable ________. voltage, resistor current, capacitor voltage, capacitor current, inductor

voltage, capacitor

What is the resistance of thermistors at room temperature (20ºC)? 5 k 1 k 100 1

5 k

What is the response time of cadmium sulfide (CdS) in photoconductive cells? 100 ms 50 ms 25 ms 10 ms

100 ms

What are the typical ranges of reverse-bias current levels IS for low-power and high-power Schottky diodes at room temperature? Picoamperes, nanoamperes Nanoamperes, microamperes Microamperes, milliamperes Milliamperes, amperes

Microamperes, milliamperes

Which of the following devices does not have a cathode terminal? SCR SCS Triac Shockley diode

Triac

Which of the following devices is unquestionably of the greatest interest today? SCR GTO LASCR SCS

SCR

Which of the following devices has a negative-resistance region in its characteristics curve? SCR SCS Unijunction transistor Phototransistor

Unijunction Transistor

How many terminals does a programmable unijunction transistor (PUT) have? 4 3 2 1

What is the typical value of the reverse resistance of SCRs? 1 to 10 100 to 1 k 1 k to 50 k 100 k or more

100 k or more

The ISO-LIT Q1 16-pin Litronix opto-isolator DIP contains ________ opto-isolators. 4 8 12 6

How many terminals does a Shockley diode have? 5 4 3 2

What is the range of the variable resistor in the equivalent circuit of a unijunction transistor? 50 to 5 k 6 k to 10 k 5 to 50 1 to 5

50 to 5 k

Which one of the SCR terminals fires the SCR? Anode Cathode Gate All of the above

Gate

Which of the following devices has the smallest turn-off time? SCR GTO SCS LASCR

GTO

What is the range of the turn-on times in high-power SCR devices? 30us to 100us 10us to 25us 5us to 8us 1us to 5us

10us to 25us

What is the frequency range of application of SCRs? About 10 kHz About 50 kHz About 250 kHz About 1 mHz

About 50 kHz

Which of the following devices has nearly the same turn-on time as turn-off time? SCR GTO SCS LASCR

GTO

Which of the transistors of an SCR are conducting when the SCR is fired and is in the conduction mode? npn pnp Both npn and pnp Neither npn nor pnp

Both npn and pnp

For an SCS, a ________ pulse at the anode gate turns the device on, while a ________ pulse will turn it off. negative, positive positive, negative

negative, positive

Which of the following devices has (have) four layers of semiconductor materials? Silicon-controlled switch (SCS) Gate turn-off switch (GTO) Light-activated silicon-controlled rectifier (LASCR) All of the above

All of the above

Which of the following parameters are usually provided by the manufacturer on the specification sheet for SCRs? Turn-on time (ton ) Turn-off time (toff ) Junction and case temperatures (tj and tc ) All of the above

All of the above

What is the maximum current (rms) rating for commercially available LASCRs today? 3 A 15 A 20 A 25 A

3 A

Which of the following areas is (are) applications of an SCS? Counters Pulse generators Voltage sensors All of the above

All of the above

How many terminals does a silicon-controlled switch (SCS) device have? 2 3 4 5

What is the typical value of the triggering anode gate for SCS devices? 1.5 mA 150 A 15 A 1 A

1.5 mA

What is the typical range of turn-off times for SCRs? 5us to 30us 1us to 5us 0.1us to 1us 0.01us to 0.1us

5us to 30us

Which of the following is (are) the advantages of the SCS over a corresponding SCR? Reduced turn-off time Increased control and triggering sensitivity More predictable firing situation All of the above

All of the above

Which of the following transistors is an SCR composed of? npn, pnp npn, npn pnp, pnp None of the above

npn, pnp

A thyristor is a ________-layer semiconductor material device. 2 3 4 5

How many layers of semiconductor materials does a silicon-controlled rectifier (SCR) have?

What is the level of the output voltage of a ladder-network conversion? The analog output voltage proportional to the digital input voltage The digital output voltage proportional to the linear input voltage A fixed digital value Vref A fixed analog value Vref

The analog output voltage proportional to the digital input voltage

Which of the following is not a linear/digital IC? Phase-locked loop Voltage-controlled oscillator Passive filter Comparator

Passive filter

A 339 IC is an example of a fourteen-pin DIP that can be made to function as a ________. comparator 555 timer D to A converter ladder network

comparator

What is the minimum number of conversions per second of a clock rate of 1 MHz operating a 10-stage counter in an ADC? 1000 976 769 697

976

Which of the following is (are) the results of improvements built into a comparator IC? Faster switching between the two output levels Noise immunity Outputs capable of directly driving a variety of loads All of the above

All of the above

What is the first phase of the dual-slope method of conversion? Connecting the analog voltage to the integrator for a fixed time Setting the counter to zero Connecting the integrator to a reference voltage All of the above

Connecting the analog voltage to the integrator for a fixed time

What is the maximum conversion time of a clock rate of 1 MHz operating a 10-stage counter in an ADC? 1.024 s 102.3 ms 10.24 ms 1.024 ms

1.024 ms

On which of the following does the conversion depend in ladder-network conversion? Comparator Control logic Digital counter Clock

Comparator

Which of the following applications include a phase-locked loop (PLL) circuit? Modems Am decoders Tracking filters All of the above

All of the above

What is the function of a ladder network? Changing an analog signal to a digital signal Changing a linear signal to a digital signal Changing a digital signal to an analog signal None of the above

Changing a digital signal to an analog signal

Which of the slope intervals of the integrator does the counter in the analog-to-digital converter (ADC) operate? Positive Negative Both positive and negative Neither positive nor negative

Both positive and negative

A 311 IC is an example of an eight-pin DIP that can be made to function as a ________. comparator 555 timer D to A converter ladder network

comparator

What is (are) the level(s) of the input voltage to a ladder-network conversion? 0 Vref 0 V or Vref None of the above

0 V or Vref

At which of the following period(s) is the counter advanced (incremented) in dual-slope conversion? During the charging of the capacitor of the integrator During the discharging of the capacitor of the integrator During both the charging and discharging of the capacitor of the integrator None of the above

During the discharging of the capacitor of the integrator

How many Vcc connections does the 565 PLL use? 0 1 2 3

What is (are) the input(s) to the comparator in the ladder-network conversion of an ADC? Staircase voltage Analog input voltage Both staircase and analog input voltage None of the above

Both staircase and analog input voltage

How many comparators does a 339 IC contain? 4 3 2 1

When is the counter set to zero in the dual-slope method of conversion? Prior to the charging of the capacitor of the integrator While the capacitor is being charged At the end of the charging of the capacitor During the discharging of the capacitor

At the end of the charging of the capacitor

Which of the following devices is (are) a component of a digital-to-analog converter (DAC)? Integrator Comparator Digital counter All of the above

All of the above

Which of the following circuits is (are) linear/digital ICs? Comparators Timers Voltage-controlled oscillators All of the above

All of the above

Which of the following best describes the output of a 566 voltage-controlled oscillator? Square-wave Triangular-wave Both square- and triangular-wave None of the above

Both square- and triangular-wave

What is the voltage resolution of an 8-stage ladder network? Vref /128 Vref /256 Vref /512 Vref /1024

Vref /256

Which of the following frequencies is associated with the 565 frequency-shift keyed decoder? 1070 Hz 1270 Hz Both 1070 Hz and 1270 Hz None of the above

Both 1070 Hz and 1270 Hz