Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

terms ^^ > digital Concepts (logic) > Flashcards

digital Concepts (logic) Flashcards

1
Q

Any number with an exponent of zero is equal to:
zero
one
that number
ten

A

one

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

In the decimal numbering system, what is the MSD?
The middle digit of a stream of numbers
The digit to the right of the decimal point
The last digit on the right
The digit with the most weight

A

The digit with the most weight

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Which of the following statements does NOT describe an advantage of digital technology?
The values may vary over a continuous range.
The circuits are less affected by noise.
The operation can be programmed.
Information storage is easy.

A

The values may vary over a continuous range.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

The generic array logic (GAL) device is ________.
one-time programmable
reprogrammable
a CMOS device
reprogrammable and a CMOS device

A

reprogrammable

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

The range of voltages between VL(max) and VH(min) are ________.
unknown
unnecessary
unacceptable
between 2 V and 5 V

A

unacceptable

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is a digital-to-analog converter?
It takes the digital information from an audio CD and converts it to a usable form.
It allows the use of cheaper analog techniques, which are always simpler.
It stores digital data on a hard drive.
It converts direct current to alternating current.

A

It takes the digital information from an audio CD and converts it to a usable form.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the symbols used to represent digits in the binary number system?
0,1
0,1,2
0 through 8
1,2

A

0,1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

A full subtracter circuit requires ________.
two inputs and two outputs
two inputs and three outputs
three inputs and one output
three inputs and two outputs

A

three inputs and two outputs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Parallel format means that:
each digital signal has its own conductor.
several digital signals are sent on each conductor.
both binary and hexadecimal can be used.
no clock is needed.

A

each digital signal has its own conductor.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

A decoder converts ________.
noncoded information into coded form
coded information into noncoded form
HIGHs to LOWs
LOWs to HIGHs

A

coded information into noncoded form

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

A DAC changes ________.
an analog signal into digital data
digital data into an analog signal
digital data into an amplified signal
none of the above

A

digital data into an analog signal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Which of the following is not an analog device?
Thermocouple
Current flow in a circuit
Light switch
Audio microphone

A

Light switch

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

A demultiplexer has ________.
one data input and a number of selection inputs, and they have several outputs
one input and one output
several inputs and several outputs
several inputs and one output

A

one data input and a number of selection inputs, and they have several outputs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

A flip-flop has ________.
one stable state
no stable states
two stable states
none of the above

A

two stable states

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Digital signals transmitted on a single conductor (and a ground) must be transmitted in:
slow speed.
parallel.
analog.
serial.

A

serial.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

In a certain digital waveform, the period is four times the pulse width. The duty cycle is ________.
0%
25%
50%
100%

A

25

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Digital representations of numerical values of quantities may BEST be described as having characteristics:
that are difficult to interpret because they are continuously changing.
that vary constantly over a continuous range of values.
that vary in constant and direct proportion to the values they represent.
that vary in discrete steps in proportion to the values they represent.

A

that vary in discrete steps in proportion to the values they represent.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

A common instrument used in troubleshooting a digital circuit is a(n) ________.
logic probe
oscilloscope
pulser
all of the above

A

ll of the above

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

The parallel transmission of digital data:
is much slower than the serial transmission of data.
requires only one signal line between sender and receiver.
requires as many signal lines between sender and receiver as there are data bits.
is less expensive than the serial method of data transmission.

A

requires as many signal lines between sender and receiver as there are data bits.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is one relative disadvantage of serial transfer?
It requires too many conductors.
Its interconnect system is complex.
It is slow.
It can only be used over very short distances.

A

It is slow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Which format requires fewer conductors?
Parallel
Serial
Both are the same
Cannot tell

A

Serial

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

The rise time is the time it takes a pulse to go from ________.
the base line to the maximum HIGH voltage
10% of the pulse amplitude to the maximum HIGH voltage
the base line to 90% of the pulse amplitude
10% of the pulse amplitude to 90% of the pulse amplitude

A

10% of the pulse amplitude to 90% of the pulse amplitude

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is an analog-to-digital converter?
It makes digital signals.
It takes analog signals and puts them in digital format.
It allows the use of digital signals in everyday life.
It stores information on a CD.

A

It takes analog signals and puts them in digital format.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

A multiplexer has ________.
one input and several outputs
one input and one output
several inputs and several outputs
several inputs and one output

A

several inputs and one output

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

An encoder converts ________.
noncoded information into coded form
coded information into noncoded form
HIGHs to LOWs
LOWs to HIGHs

A

noncoded information into coded form

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What kind of logic device or circuit is used to store information?
Counter
Register
Inverter
Buffer

A

Register

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

PLCC packages have leads on ________.
one side
two sides
three sides
four sides

A

four sides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What is the typical invalid voltage for a binary signal?
0.7–2.8 volts
0.8–3 volts
0.8–2 volts
0.7–2.5 volts

A

0.8-2 volts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

How many binary bits are necessary to represent 748 different numbers?
9
7
10
8

A

10

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Serial format means digital signals are:
sent over many conductors simultaneously.
sent over one conductor sequentially.
sent in groups of eight signals.
sent in binary coded decimal.

A

sent over one conductor sequentially.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Which format can send several bits of information faster?
Parallel
Serial
Both are the same
Cannot tell

A

Parallel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What has happened to the advances in digital technologies over the past three decades?
Slowed down considerably
Continued to increase, but at a decreasing rate
Made excellent progress
Nothing short of phenomenal

A

Nothing short of phenomenal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

A type of digital circuit technology that uses bipolar junction transistors is ________.
TTL
CMOS
LSI
NMOS

A

TTL

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

How many unique symbols are used in the decimal number system?
One
Nine
Ten
Unlimited

A

Ten

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

One hex digit is sometimes referred to as a(n):
byte
nibble
grouping
instruction

A

nibble

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Which of the following is the most widely used alphanumeric code for computer input and output?
Gray
ASCII
Parity
EBCDIC

A

ASCII

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

If a typical PC uses a 20-bit address code, how much memory can the CPU address?
20 MB
10 MB
1 MB
580 MB

A

1 MB

38
Q

Which is typically the longest: bit, byte, nibble, word?
Bit
Byte
Nibble
Word

A

Word

39
Q

A binary number’s value changes most drastically when the ________ is changed.
MSB
frequency
LSB
duty cycle

A

MSB

40
Q

Which is not a word size?
64
28
16
8

A

28

41
Q

The octal numbering system:
simplifies tasks
groups binary numbers in groups of 4
saves time
simplifies tasks and saves time

A

simplifies tasks and saves time

42
Q

When using even parity, where is the parity bit placed?
Before the MSB
After the LSB
In the parity word
After the odd parity bit

A

Before the MSB

43
Q

An analog signal has a range from 0 V to 5 V. What is the total number of analog possibilities within this range?
5
50
250
infinite

A

infinite

44
Q

Hexadecimal letters A through F are used for decimal equivalent values from:
1 through 6
9 through 14
10 through 15
11 through 17

A

10 through 15

45
Q

What is the difference between binary coding and binary-coded decimal?
BCD is pure binary.
Binary coding has a decimal format.
BCD has no decimal format.
Binary coding is pure binary.

A

Binary coding is pure binary.

46
Q

Digital electronics is based on the ________ numbering system.
decimal
octal
binary
hexadecimal

A

binary

47
Q

An informational signal that makes use of binary digits is considered to be:
solid state
digital
analog
non-oscillating

A

digital

48
Q

The binary-coded decimal (BCD) system can be used to represent each of the 10 decimal digits as a(n):
4-bit binary code
8-bit binary code
16-bit binary code
ASCII code

A

4-bit binary code

49
Q

The American Standard Code for Information Interchange (ASCII) uses how many individual pulses for any given character?
1
2
7
8

A

7

50
Q

Alphanumeric codes should include as a minimum:
the capacity to represent the alphabet upper- and lowercase characters and the decimal numbers in a straight binary format.
the capacity to code all possible decimal numbers in a direct octal representation of BCD codes.
the alphabet upper- and lowercase letters, the decimal digits, the seven punctuation marks, and other characters or symbols.
the ability to represent decimal numbers greater than 12810 in a straight binary format.

A

the alphabet upper- and lowercase letters, the decimal digits, the seven punctuation marks, and other characters or symbols.

51
Q

Select one of the following statements that best describes the parity method of error detection.
Parity checking is best suited for detecting single-bit errors in transmitted codes.
Parity checking is not suitable for detecting single-bit errors in transmitted codes.
Parity checking is capable of detecting and correcting errors in transmitted codes.
Parity checking is best suited for detecting double-bit errors that occur during the transmission of codes from one location to another.

A

Parity checking is best suited for detecting single-bit errors in transmitted codes.

52
Q

Which of the following is the primary advantage of using the BCD code instead of straight binary coding?
Fewer bits are required to represent a decimal number with the BCD code.
The relative ease of converting to and from decimal.
BCD codes are easily converted to hexadecimal codes.
BCD codes are easily converted to straight binary codes.

A

The relative ease of converting to and from decimal

53
Q

When using the repeated division by 2 method of converting from decimal to binary, one must write the first remainder as the:
MSB
MSB, provided the following sequence of remainders are written in descending order until the final remainder is achieved.
LSB
LSB, provided the final remainder is used to replace the original LSB, which is then moved to the MSB position.

A

LSB

54
Q

A device used to display one or more digital signals so that they can be compared to expected timing diagrams for the signals is a:
DMM
spectrum analyzer
logic analyzer
frequency counter

A

logic analyzer

55
Q

How many pins does the 4049 IC have?
14
16
18
20

A

16

56
Q

Which of the following choices meets the minimum requirement needed to create specialized waveforms that are used in digital control and sequencing circuits?
basic gates, a clock oscillator, and a repetitive waveform generator
basic gates, a clock oscillator, and a Johnson shift counter
basic gates, a clock oscillator, and a DeMorgan pulse generator
basic gates, a clock oscillator, a repetitive waveform generator, and a Johnson shift counter

A

basic gates, a clock oscillator, and a repetitive waveform generator

57
Q

TTL operates from a ________.
9-volt supply
3-volt supply
12-volt supply
5-volt supply

A

5-volt supply

58
Q

The switching speed of CMOS is now ________.
competitive with TTL
three times that of TTL
slower than TTL
twice that of TTL

A

competitive with TTL

59
Q

The format used to present the logic output for the various combinations of logic inputs to a gate is called a(n):
Boolean constant
Boolean variable
truth table
input logic function

A

truth table

60
Q

The power dissipation, PD, of a logic gate is the product of the ________.
dc supply voltage and the peak current
dc supply voltage and the average supply current
ac supply voltage and the peak current
ac supply voltage and the average supply current

A

dc supply voltage and the average supply current

61
Q

A CMOS IC operating from a 3-volt supply will consume ________.
less power than a TTL IC
more power than a TTL IC
the same power as a TTL IC
no power at all

A

less power than a TTL IC

62
Q

What are the pin numbers of the outputs of the gates in a 7432 IC?
3, 6, 10, and 13
1, 4, 10, and 13
3, 6, 8, and 11
1, 4, 8, and 11

A

3, 6, 8, and 11

63
Q

A logic probe is placed on the output of a gate and the display indicator is dim. A pulser is used on each of the input terminals, but the output indication does not change. What is wrong?
The dim indication on the logic probe indicates that the supply voltage is probably low.
The output of the gate appears to be open.
The dim indication is the result of a bad ground connection on the logic probe.
The gate is a tristate device.

A

The output of the gate appears to be open

64
Q

What is the difference between a 7400 and a 7411 IC?
7400 has two four-input NAND gates; 7411 has three three-input AND gates
7400 has four two-input NAND gates; 7411 has three three-input AND gates
7400 has two four-input AND gates; 7411 has three three-input NAND gates
7400 has four two-input AND gates; 7411 has three three-input NAND gates

A

7400 has four two-input NAND gates; 7411 has three three-input AND gates

65
Q

The AND function can be used to ________ and the OR function can be used to ________ .
enable, disable
disable, enable
enable or disable, enable or disable
detect, invert

A

enable or disable, enable or disable

66
Q

One advantage TTL has over CMOS is that TTL is ________.
less expensive
not sensitive to electrostatic discharge
faster
more widely available

A

not sensitive to electrostatic discharge

67
Q

Fan-out is specified in terms of ________.
voltage
current
wattage
unit loads

A

unit loads

68
Q

What is the circuit number of the IC that contains four two-input AND gates in standard TTL?
7402
7404
7408
7432

A

7408

69
Q

The terms “low speed” and “high speed,” applied to logic circuits, refer to the ________.
rise time
fall time
propagation delay time
clock spee

A

propagation delay time

70
Q

The term “hex inverter” refers to:
an inverter that has six inputs
six inverters in a single package
a six-input symbolic logic device
an inverter that has a history of failure

A

six inverters in a single package

71
Q

How many inputs are on the logic gates of a 74HC21 IC?
1
2
3
4

A

4

72
Q

How many AND gates are found in a 7411 IC?
1
2
3
4

A

3

73
Q

What is the name of a digital circuit that produces several repetitive digital waveforms?
an inverter
an OR gate
a Johnson shift counter
an AND gate

A

a Johnson shift counter

74
Q

The basic types of programmable arrays are made up of ________.
AND gates
OR gates
NAND and NOR gates
AND gates and OR gates

A

AND gates and OR gates

75
Q

CMOS IC packages are available in ________.
DIP configuration
SOIC configuration
DIP and SOIC configurations
neither DIP nor SOIC configurations

A

DIP and SOIC configurations

76
Q

Select the statement that best describes the parity method of error detection:
Parity checking is best suited for detecting double-bit errors that occur during the transmission of codes from one location to another.
Parity checking is not suitable for detecting single-bit errors in transmitted codes.
Parity checking is best suited for detecting single-bit errors in transmitted codes.
Parity checking is capable of detecting and correcting errors in transmitted codes.

A

Parity checking is best suited for detecting single-bit errors in transmitted codes.

77
Q

Parity systems are defined as either________ or ________ and will add an extra ________ to the digital information being transmitted.
positive, negative, byte
odd, even, bit
upper, lower, digit
on, off, decimal

A

odd, even, bit

78
Q

The Ex-NOR is sometimes called the ________.
parity gate
equality gate
inverted OR
parity gate or the equality gate

A

equality gate

79
Q

The systematic reduction of logic circuits is accomplished by:
using Boolean algebra
symbolic reduction
TTL logic
using a truth table

A

using Boolean algebra

80
Q

What is the primary motivation for using Boolean algebra to simplify logic expressions?
It may make it easier to understand the overall function of the circuit.
It may reduce the number of gates.
It may reduce the number of inputs required.
all of the above

A

all of the above

81
Q

When grouping cells within a K-map, the cells must be combined in groups of ________.
2s
1, 2, 4, 8, etc.
4s
3s

A

1, 2, 4, 8, etc.

82
Q

Occasionally, a particular logic expression will be of no consequence in the operation of a circuit, such as a BCD-to-decimal converter. These result in ________terms in the K-map and can be treated as either ________ or ________, in order to ________ the resulting term.
don’t care, 1s, 0s, simplify
spurious, ANDs, ORs, eliminate
duplicate, 1s, 0s, verify
spurious, 1s, 0s, simplify

A

don’t care, 1s, 0s, simplify

83
Q

The NAND or NOR gates are referred to as “universal” gates because either:
can be found in almost all digital circuits
can be used to build all the other types of gates
are used in all countries of the world
were the first gates to be integrated

A

can be used to build all the other types of gates

84
Q

Which statement below best describes a Karnaugh map?
A Karnaugh map can be used to replace Boolean rules.
The Karnaugh map eliminates the need for using NAND and NOR gates.
Variable complements can be eliminated by using Karnaugh maps.
Karnaugh maps provide a cookbook approach to simplifying Boolean expressions.

A

Karnaugh maps provide a cookbook approach to simplifying Boolean expressions.

85
Q

Which of the following is an important feature of the sum-of-products (SOP) form of expression?
All logic circuits are reduced to nothing more than simple AND and OR gates.
The delay times are greatly reduced over other forms.
No signal must pass through more than two gates, not including inverters.
The maximum number of gates that any signal must pass through is reduced by a factor of two.

A

No signal must pass through more than two gates, not including inverters.

86
Q

The commutative law of addition and multiplication indicates that:
we can group variables in an AND or in an OR any way we want
an expression can be expanded by multiplying term by term just the same as in ordinary algebra
the way we OR or AND two variables is unimportant because the result is the same
the factoring of Boolean expressions requires the multiplication of product terms that contain like variables

A

the way we OR or AND two variables is unimportant because the result is the same

87
Q

Which of the following combinations cannot be combined into K-map groups?
corners in the same row
corners in the same column
diagonal
overlapping combinations

A

diagonal

88
Q

The format used to present the logic output for the various combinations of logic inputs to a gate is called a(n):
truth table.
input logic function.
Boolean constant.
Boolean variable.

A

truth table.

89
Q

What is the basic difference between AHDL and VHDL?
ADHL is used in all PLD’s.
VHDL is used in all PLD’s.
ADHL is proprietary.
VHDL is proprietary.

A

ADHL is proprietary.

90
Q

In VHDL, the mode of a port does not define:
an input.
an output.
both an input and an output.
the TYPE of the bit.

A

the TYPE of the bit

91
Q

How are the statements between BEGIN and END not evaluated in VHDL?
Constantly
Simultaneously
Concurrently
Sequentially

A

Sequentially

92
Q

The special software application that translates from HDL into a grid of 1’s and 0’s, which can be loaded into a PLD, is called a:
formatter.
compiler.
programmable wiring.
CPU.

A

compiler.

terms ^^ (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions