Explore topic-wise MCQs in Engineering.

This section includes 2291 Mcqs, each offering curated multiple-choice questions to sharpen your Engineering knowledge and support exam preparation. Choose a topic below to get started.

51.

Which of the following logical operations is represented by the + sign in Boolean algebra?

A. inversion
B. AND
C. OR
D. complementation
Answer» D. complementation
Discussion
52.

Output will be a LOW for any case when one or more inputs are zero for a(n):

A. OR gate
B. NOT gate
C. AND gate
D. NOR gate
Answer» D. NOR gate
Discussion
53.

An OR gate with schematic "bubbles" on its inputs performs the same functions as a(n)________ gate.

A. NOR
B. OR
C. NOT
D. NAND
Answer» E.
Discussion
54.

Determine the binary values of the variables for which the following standard POS expression is equal to 0.

A. (0 + 1 + 0)(1 + 0 + 1)
B. (1 + 1 + 1)(0 + 0 + 0)
C. (0 + 0 + 0)(1 + 0 + 1)
D. (1 + 1 + 0)(1 + 0 + 0)
Answer» B. (1 + 1 + 1)(0 + 0 + 0)
Discussion
55.

The AND function can be used to ________ and the OR function can be used to ________ .

A. enable, disable
B. disable, enable
C. enable or disable, enable or disable
D. detect, invert
Answer» D. detect, invert
Discussion
56.

Logically, the output of a NOR gate would have the same Boolean expression as a(n):

A. NAND gate immediately followed by an inverter
B. OR gate immediately followed by an inverter
C. AND gate immediately followed by an inverter
D. NOR gate immediately followed by an inverter
Answer» C. AND gate immediately followed by an inverter
Discussion
57.

If a 3-input NOR gate has eight input possibilities, how many of those possibilities will result in a HIGH output?

A. 1
B. 2
C. 7
D. 8
Answer» B. 2
Discussion
58.

If a signal passing through a gate is inhibited by sending a LOW into one of the inputs, and the output is HIGH, the gate is a(n):

A. AND
B. NAND
C. NOR
D. OR
Answer» C. NOR
Discussion
59.

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:

A. DMM
B. spectrum analyzer
C. logic analyzer
D. frequency counter
Answer» D. frequency counter
Discussion
60.

When used with an IC, what does the term "QUAD" indicate?

A. 2 circuits
B. 4 circuits
C. 6 circuits
D. 8 circuits
Answer» C. 6 circuits
Discussion
61.

CMOS IC packages are available in ________.

A. DIP configuration
B. SOIC configuration
C. DIP and SOIC configurations
D. neither DIP nor SOIC configurations
Answer» D. neither DIP nor SOIC configurations
Discussion
62.

How many entries would a truth table for a four-input NAND gate have?

A. 2
B. 8
C. 16
D. 32
Answer» D. 32
Discussion
63.

Which of the following is not a basic Boolean operation?

A. OR
B. NOT
C. AND
D. FOR
Answer» E.
Discussion
64.

Which of the following gates is described by the expression ?

A. OR
B. AND
C. NOR
D. NAND
Answer» E.
Discussion
65.

How many AND gates are found in a 7411 IC?

A. 1
B. 2
C. 3
D. 4
Answer» D. 4
Discussion
66.

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

A. 1 + 1 + 0 + 0 = 01
B. 1 + 1 + 0 + 0 = 1
C. 1 + 1 + 0 + 0 = 0
D. 1 + 1 + 0 + 0 = 00
Answer» C. 1 + 1 + 0 + 0 = 0
Discussion
67.

The Boolean expression for a 3-input OR gate is ________.

A. X = A + B
B. X = A + B + C
C. X = ABC
D. X = A + BC
Answer» C. X = ABC
Discussion
68.

The logic gate that will have a LOW output when any one of its inputs is HIGH is the:

A. NAND gate
B. AND gate
C. NOR gate
D. OR gate
Answer» D. OR gate
Discussion
69.

The output of a NAND gate is LOW if ________.

A. all inputs are LOW
B. all inputs are HIGH
C. any input is LOW
D. any input is HIGH
Answer» C. any input is LOW
Discussion
70.

One advantage TTL has over CMOS is that TTL is ________.

A. less expensive
B. not sensitive to electrostatic discharge
C. faster
D. more widely available
Answer» C. faster
Discussion
71.

A 2-input NOR gate is equivalent to a ________.

A. negative-OR gate
B. negative-AND gate
C. negative-NAND gate
D. none of the above
Answer» C. negative-NAND gate
Discussion
72.

If a 3-input OR gate has eight input possibilities, how many of those possibilities will result in a HIGH output?

A. 1
B. 2
C. 7
D. 8
Answer» D. 8
Discussion
73.

How many input combinations would a truth table have for a six-input AND gate?

A. 32
B. 48
C. 64
D. 128
Answer» D. 128
Discussion
74.

How many truth table entries are necessary for a four-input circuit?

A. 4
B. 8
C. 12
D. 16
Answer» E.
Discussion
75.

What is the name of a digital circuit that produces several repetitive digital waveforms?

A. an inverter
B. an OR gate
C. a Johnson shift counter
D. an AND gate
Answer» D. an AND gate
Discussion
76.

The basic types of programmable arrays are made up of ________.

A. AND gates
B. OR gates
C. NAND and NOR gates
D. AND gates and OR gates
Answer» E.
Discussion
77.

The logic gate that will have HIGH or "1" at its output when any one (or more) of its inputs is HIGH is a(n):

A. OR gate
B. AND gate
C. NOR gate
D. NOT operation
Answer» B. AND gate
Discussion
78.

The term "hex inverter" refers to:

A. an inverter that has six inputs
B. six inverters in a single package
C. a six-input symbolic logic device
D. an inverter that has a history of failure
Answer» C. a six-input symbolic logic device
Discussion
79.

How many inputs are on the logic gates of a 74HC21 IC?

A. 1
B. 2
C. 3
D. 4
Answer» E.
Discussion
80.

The basic logic gate whose output is the complement of the input is the:

A. OR gate
B. AND gate
C. inverter
D. comparator
Answer» D. comparator
Discussion
81.

When reading a Boolean expression, what does the word "NOT" indicate?

A. the same as
B. inversion
C. high
D. low
Answer» C. high
Discussion
82.

The output of an exclusive-NOR gate is HIGH if ________.

A. the inputs are equal
B. one input is HIGH, and the other input is LOW
C. the inputs are unequal
D. none of the above
Answer» B. one input is HIGH, and the other input is LOW
Discussion
83.

The NOR logic gate is the same as the operation of the ________ gate with an inverter connected to the output.

A. OR
B. AND
C. NAND
D. none of the above
Answer» B. AND
Discussion
84.

With regard to an AND gate, which statement is true?

A. An AND gate has two inputs and one output.
B. An AND gate has two or more inputs and two outputs.
C. If one input to a 2-input AND gate is HIGH, the output reflects the other input.
D. A 2-input AND gate has eight input possibilities.
Answer» D. A 2-input AND gate has eight input possibilities.
Discussion
85.

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

A. 7402
B. 7404
C. 7408
D. 7432
Answer» D. 7432
Discussion
86.

The terms "low speed" and "high speed," applied to logic circuits, refer to the ________.

A. rise time
B. fall time
C. propagation delay time
D. clock speed
Answer» D. clock speed
Discussion
87.

Referring to the GAL diagram, which is the correct logic function?

A. <img src="/_files/images/digital-electronics/digital-fundamentals/mca5_0220a.gif">
B. <img src="/_files/images/digital-electronics/digital-fundamentals/mca5_0220b.gif">
C. <img src="/_files/images/digital-electronics/digital-fundamentals/mca5_0220c.gif">
D. <img src="/_files/images/digital-electronics/digital-fundamentals/mca5_0220d.gif">
Answer» B. <img src="/_files/images/digital-electronics/digital-fundamentals/mca5_0220b.gif">
Discussion
88.

How many AND gates are required to implement the Boolean expression, ?

A. 1
B. 2
C. 3
D. 4
Answer» D. 4
Discussion
89.

How many NOT gates are required to implement the Boolean expression, ?

A. 1
B. 2
C. 4
D. 5
Answer» C. 4
Discussion
90.

The inverter can be produced with how many NAND gates?

A. 1
B. 2
C. 3
D. 4
Answer» B. 2
Discussion
91.

Before an SOP implementation, the expression would require a total of how many gates?

A. 1
B. 2
C. 4
D. 5
Answer» E.
Discussion
92.

TTL logic chips must have connections to Vcc and ground, even if all inputs and outputs are properly used and tied to valid signals.

A. True
B. False
Answer» B. False
Discussion
93.

If the input voltage on D1 in the given figure is changed to 0 V, what is the output voltage Vout?

A. 5 V
B. 0 V
C. +5 V
D. +4.3 V
Answer» C. +5 V
Discussion
94.

An indication of cutoff in an NPN bipolar transistor is that the:

A. collector current is maximum
B. collector-to-emitter voltage equals zero
C. base-to-emitter voltage equals 0.7 V
D. collector to emitter appears to be open
Answer» E.
Discussion
95.

When an IC has two rows of parallel connecting pins, the device is referred to as a:

A. QFP
B. DIP
C. TSSOP
D. CMOS
Answer» C. TSSOP
Discussion
96.

Serial communication can be sped up by:

A. using silver or gold conductors instead of copper
B. using high-speed clock signals
C. adjusting the duty cycle of the binary information
D. using silver or gold conductors instead of copper and high-speed clock signals
Answer» C. adjusting the duty cycle of the binary information
Discussion
97.

What is the output voltage Vout for the given circuit if the input voltage changes to 0 V?

A. +12 V
B. +15 V
C. +3 V
D. 0 V
Answer» B. +15 V
Discussion
98.

With surface-mount technology (SMT), the devices should:

A. utilize transistor outline connections
B. mount directly
C. have parallel connecting pins
D. require holes and pads
Answer» C. have parallel connecting pins
Discussion
99.

To forward bias a diode, a ________ potential is needed on the ________ and a ________ is needed on the ________.

A. negative, cathode, positive, anode
B. negative, anode, positive, cathode
Answer» B. negative, anode, positive, cathode
Discussion
100.

Why, in most applications, are transistor switches used in place of relays?

A. They consume less power.
B. They are faster.
C. They are quieter and smaller.
D. all of the above
Answer» E.
Discussion