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

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.

The parallel transmission of digital data:

is less expensive than the serial method of data transmission.

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 demultiplexer has ________.

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

several inputs and several outputs

An encoder converts ________.

coded information into noncoded form

noncoded information into coded form

coded information into noncoded form

What has happened to the advances in digital technologies over the past three decades?

Continued to increase, but at a decreasing rate

Which of the following statements does NOT describe an advantage of digital technology?

The circuits are less affected by noise.

The values may vary over a continuous range.

The circuits are less affected by noise.

The operation can be programmed.

The generic array logic (GAL) device is ________.

reprogrammable and a CMOS device

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

What is the major advantage of ECL logic?

wide range of operating voltage

As a general rule, the lower the value of the speed power product, the better the device because of its:

long propagation delay and high power consumption

long propagation delay and low power consumption

What is the difference between the 54XX and 74XX series of TTL logic gates?

54XX has a narrower power supply and contracted temperature range.

54XX has a wider power supply and expanded temperature range.

54XX has a narrower power supply and contracted temperature range.

Why is a decoupling capacitor needed for TTL ICs and where should it be connected?

to block dc, connect to input pins

to reduce noise, connect to input pins

to reduce the effects of noise, connect between power supply and ground

Why is the fan-out of CMOS gates frequency dependent?

Each CMOS input gate has a specific propagation time and this limits the number of different gates that can be connected to the output of a CMOS gate.

When the frequency reaches the critical value, the gate will only be capable of delivering 70% of the normal output voltage and consequently the output power will be one-half of normal; this defines the upper operating frequency.

The higher the number of gates attached to the output, the more frequently they will have to be serviced, thus reducing the frequency at which each will be serviced with an input signal.

The input gates of the FETs are predominantly capacitive, and as the signal frequency increases the capacitive loading also increases, thereby limiting the number of loads that may be attached to the output of the driving gate.

Logic circuits that are designated as buffers, drivers, or buffer/drivers are designed to have:

greater input current/voltage capability than an ordinary logic circuit.

a greater current/voltage capability than an ordinary logic circuit.

greater input current/voltage capability than an ordinary logic circuit.

a smaller output current/voltage capability than an ordinary logic.

greater input and output current/voltage capability than an ordinary logic circuit.

Which of the following will not normally be found on a data sheet?

Maximum HIGH level input current

Minimum HIGH level output voltage

Maximum LOW level output voltage

Minimum LOW level output voltage

Maximum HIGH level input current

2291 + Mcqs in Digital Electronics in Engineering Page 4 McqOptions

151.	The rise time is the time it takes a pulse to go from ________.
A.	the base line to the maximum HIGH voltage
B.	10% of the pulse amplitude to the maximum HIGH voltage
C.	the base line to 90% of the pulse amplitude
D.	10% of the pulse amplitude to 90% of the pulse amplitude
Answer» E.

152.	Convert the fractional decimal number 6.75 to binary.
A.	0111.1100
B.	0110.1010
C.	0110.1100
D.	0110.0110
Answer» D. 0110.0110

153.	A pulse has a period of 15 ms. Its frequency is ________.
A.	6.66 Hz
B.	66.66 Hz
C.	666.66 Hz
D.	15 Hz
Answer» C. 666.66 Hz

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

155.	A common instrument used in troubleshooting a digital circuit is a(n) ________.
A.	logic probe
B.	oscilloscope
C.	pulser
D.	all of the above
Answer» E.

156.	In positive logic, ________.
A.	a HIGH = 1, a LOW = 0
B.	a LOW = 1, a HIGH = 0
C.	only HIGHs are present
D.	only LOWs are present
Answer» B. a LOW = 1, a HIGH = 0

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

158.	Convert the fractional binary number 0000.1010 to decimal.
A.	0.625
B.	0.50
C.	0.55
D.	0.10
Answer» B. 0.50

159.	Which of the following is not an analog device?
A.	Thermocouple
B.	Current flow in a circuit
C.	Light switch
D.	Audio microphone
Answer» D. Audio microphone

160.	Digital signals transmitted on a single conductor (and a ground) must be transmitted in:
A.	slow speed.
B.	parallel.
C.	analog.
D.	serial.
Answer» E.

161.	In a certain digital waveform, the period is four times the pulse width. The duty cycle is ________.
A.	0%
B.	25%
C.	50%
D.	100%
Answer» C. 50%

163.	A flip-flop has ________.
A.	one stable state
B.	no stable states
C.	two stable states
D.	none of the above
Answer» D. none of the above

165.	Convert the fractional binary number 0001.0010 to decimal.
A.	1.40
B.	1.125
C.	1.20
D.	1.80
Answer» C. 1.20

167.	Convert the fractional binary number 10010.0100 to decimal.
A.	24.50
B.	18.25
C.	18.40
D.	16.25
Answer» C. 18.40

170.	A type of digital circuit technology that uses bipolar junction transistors is ________.
A.	TTL
B.	CMOS
C.	LSI
D.	NMOS
Answer» B. CMOS

162.	A demultiplexer has ________.
A.	one data input and a number of selection inputs, and they have several outputs
B.	one input and one output
C.	several inputs and several outputs
D.	several inputs and one output
Answer» B. one input and one output

164.	What is the decimal value of 2³?
A.	2
B.	4
C.	6
D.	8
Answer» E.

166.	An encoder converts ________.
A.	noncoded information into coded form
B.	coded information into noncoded form
C.	HIGHs to LOWs
D.	LOWs to HIGHs
Answer» B. coded information into noncoded form

168.	A full subtracter circuit requires ________.
A.	two inputs and two outputs
B.	two inputs and three outputs
C.	three inputs and one output
D.	three inputs and two outputs
Answer» E.

169.	What has happened to the advances in digital technologies over the past three decades?
A.	Slowed down considerably
B.	Continued to increase, but at a decreasing rate
C.	Made excellent progress
D.	Nothing short of phenomenal
Answer» E.

171.	Which format can send several bits of information faster?
A.	Parallel
B.	Serial
C.	Both are the same
D.	Cannot tell
Answer» B. Serial

172.	A classification of ICs with complexities of 12 to 100 equivalent gates on a chip is known as ________.
A.	SSI
B.	MSI
C.	LSI
D.	VLSI
Answer» C. LSI

173.	The output of an AND gate is LOW ________.
A.	all the time
B.	when any input is LOW
C.	when any input is HIGH
D.	when all inputs are HIGH
Answer» C. when any input is HIGH

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

175.	The generic array logic (GAL) device is ________.
A.	one-time programmable
B.	reprogrammable
C.	a CMOS device
D.	reprogrammable and a CMOS device
Answer» C. a CMOS device

Explore topic-wise MCQs in Engineering.

The rise time is the time it takes a pulse to go from ________.

Convert the fractional decimal number 6.75 to binary.

A pulse has a period of 15 ms. Its frequency is ________.

Digital representations of numerical values of quantities may BEST be described as having characteristics:

A common instrument used in troubleshooting a digital circuit is a(n) ________.

In positive logic, ________.

The parallel transmission of digital data:

Convert the fractional binary number 0000.1010 to decimal.

Which of the following is not an analog device?

Digital signals transmitted on a single conductor (and a ground) must be transmitted in:

In a certain digital waveform, the period is four times the pulse width. The duty cycle is ________.

A demultiplexer has ________.

A flip-flop has ________.

What is the decimal value of 23 ?

Convert the fractional binary number 0001.0010 to decimal.

An encoder converts ________.

Convert the fractional binary number 10010.0100 to decimal.

A full subtracter circuit requires ________.

What has happened to the advances in digital technologies over the past three decades?

A type of digital circuit technology that uses bipolar junction transistors is ________.

Which format can send several bits of information faster?

A classification of ICs with complexities of 12 to 100 equivalent gates on a chip is known as ________.

The output of an AND gate is LOW ________.

Which of the following statements does NOT describe an advantage of digital technology?

The generic array logic (GAL) device is ________.

In the decimal numbering system, what is the MSD?

The range of voltages between VL(max) and VH(min) are ________.

Implementing the expression AB + CDE using NAND logic, we get:

The Boolean SOP expression obtained from the truth table below is ________.

The 8-input XOR circuit shown has an output of Y = 1. Which input combination below (ordered A H) is correct?

Can a 74HCMOS logic gate directly connect to a 74ALSTTL gate?

What is the major advantage of ECL logic?

As a general rule, the lower the value of the speed power product, the better the device because of its:

What is the range of invalid TTL output voltage?

Assume that a particular IC has a supply voltage (Vcc) equal to +5 V and ICCH = 10 mA and ICCL = 23 mA. What is the power dissipation for the chip?

An open collector output can ________ current, but it cannot ________.

What is the difference between the 54XX and 74XX series of TTL logic gates?

Why is a decoupling capacitor needed for TTL ICs and where should it be connected?

Why is the fan-out of CMOS gates frequency dependent?

Which of the following logic families has the highest maximum clock frequency?

Logic circuits that are designated as buffers, drivers, or buffer/drivers are designed to have:

Which of the following will not normally be found on a data sheet?

Which of the following is a form of DeMorgan's theorem?

How are the statements between BEGIN and END not evaluated in VHDL?

Which logic gate does this truth table describe?

For a 3-input NAND gate, with the input waveforms as shown below, which output waveform is correct?

Which of the figures (a to d) is the DeMorgan equivalent of Figure (e)?

In VHDL, the mode of a port does not define:

Which of the following equations would accurately describe a 4-input OR gate when A = 1, B = 1, C = 0, and D = 0?

Which of the following logic families has the shortest propagation delay?

What is the decimal value of 2³?

The range of voltages between V_L(max) and V_H(min) are ________.

Assume that a particular IC has a supply voltage (V_cc) equal to +5 V and I_CCH = 10 mA and I_CCL = 23 mA. What is the power dissipation for the chip?

An open collector output can current, but it cannot .

176.	In the decimal numbering system, what is the MSD?
A.	The middle digit of a stream of numbers
B.	The digit to the right of the decimal point
C.	The last digit on the right
D.	The digit with the most weight
Answer» E.

177.	The range of voltages between V_L(max) and V_H(min) are ________.
A.	unknown
B.	unnecessary
C.	unacceptable
D.	between 2 V and 5 V
Answer» D. between 2 V and 5 V

178.	Implementing the expression AB + CDE using NAND logic, we get:
A.	(A)
B.	(B)
C.	(C)
D.	(D)
Answer» B. (B)

179.	The Boolean SOP expression obtained from the truth table below is ________.
A.	<img src="/_files/images/digital-electronics/digital-fundamentals/mca5_0090a.gif">
B.	<img src="/_files/images/digital-electronics/digital-fundamentals/mca5_0090b.gif">
C.	<img src="/_files/images/digital-electronics/digital-fundamentals/mca5_0090c.gif">
D.	None of these
Answer» D. None of these

180.	The 8-input XOR circuit shown has an output of Y = 1. Which input combination below (ordered A H) is correct?
A.	10111100
B.	10111000
C.	11100111
D.	00011101
Answer» B. 10111000

181.	Can a 74HCMOS logic gate directly connect to a 74ALSTTL gate?
A.	Yes
B.	No
Answer» B. No

182.	What is the major advantage of ECL logic?
A.	very high speed
B.	wide range of operating voltage
C.	very low cost
D.	very high power
Answer» B. wide range of operating voltage

183.	As a general rule, the lower the value of the speed power product, the better the device because of its:
A.	long propagation delay and high power consumption
B.	long propagation delay and low power consumption
Answer» C.

184.	What is the range of invalid TTL output voltage?
A.	0.0 0.4 V
B.	0.4 2.4 V
C.	2.4 5.0 V
D.	0.0 5.0 V
Answer» C. 2.4 5.0 V

185.	Assume that a particular IC has a supply voltage (V_cc) equal to +5 V and I_CCH = 10 mA and I_CCL = 23 mA. What is the power dissipation for the chip?
A.	50 mW
B.	82.5 mW
C.	115 mW
D.	165 mW
Answer» C. 115 mW