Logic Gates: Interactive Quizzes for Electronics I

Question 1

Which of the following is NOT a fundamental logic gate?

Accepted Answer

Half Adder

Answer

AND gate

Answer

OR gate

Question 2

Which characteristic primarily distinguishes a combinatorial logic gate from a sequential logic gate?

Accepted Answer

Combinatorial logic gates are used in combinational circuits, while sequential logic gates are used in sequential circuits.

Answer

Combinatorial logic gates have memory, while sequential logic gates do not.

Answer

Sequential logic gates have a fixed output, unlike combinatorial logic gates.

Answer

Combinatorial logic gates have only one input, while sequential logic gates have multiple inputs.

Question 3

When both inputs of a 2-input OR gate are '0', what is the output?

Accepted Answer

0

Answer

1

Question 4

Which of the following is NOT a characteristic of a CMOS inverter?

Accepted Answer

High output impedance

Answer

Low power consumption

Answer

High input impedance

Answer

Unity voltage gain

Question 5

In a logic gate circuit, what is the purpose of a pull-down resistor?

Accepted Answer

To provide a defined output level when the gate is not driven

Answer

To prevent unwanted current flow

Answer

To increase the speed of the circuit

Answer

To protect the gate from damage

Question 6

Among the following logic gate types, which one typically has the highest fan-out capability?

Accepted Answer

TTL totem-pole output

Answer

CMOS open-drain output

Answer

NMOS open-collector output

Answer

ECL current-mode output

Question 7

In digital circuits, what is a primary advantage of using voltage levels to represent logic values?

Accepted Answer

Noise immunity

Answer

Simplicity of implementation

Answer

Low power consumption

Answer

High speed

Question 8

Which of the following is a potential disadvantage of using logic gates with open-collector outputs?

Accepted Answer

Require pull-up resistors

Answer

Limited fan-out capability

Answer

Slower switching speeds

Answer

Higher power consumption

Question 9

In troubleshooting digital circuits, what is the primary function of a logic probe?

Accepted Answer

To indicate the logic level present at a specific point in the circuit

Answer

To generate test signals

Answer

To measure voltage and current

Answer

To identify faulty components

Question 10

A logic gate with an output that is '1' when any of its inputs are '1' is a:

Accepted Answer

OR gate

Answer

AND gate

Answer

NAND gate

Answer

NOR gate

Question 11

The Boolean expression for a NAND gate is:

Accepted Answer

(A + B)'

Answer

A + B

Answer

A * B

Answer

A' + B'

Question 12

A circuit with multiple inputs and a single output that performs a logical operation on its inputs is called a:

Accepted Answer

Logic gate

Answer

Combinational circuit

Answer

Sequential circuit

Answer

Flip-flop

Question 13

Which of the following logic gate symbols represents an inverter?

Accepted Answer

!

Answer

||

Answer

&&

Answer

##

Question 14

Design a logic circuit using logic gates to implement a 4-bit binary adder. The adder should accept two 4-bit binary numbers as inputs and generate their sum as a 4-bit binary number.

Accepted Answer

A circuit using a combination of AND, OR, and NOT gates

Answer

A circuit using only AND gates

Answer

A circuit using only OR gates

Answer

A circuit using only NAND gates

Question 15

To test the functionality of a logic gate in a digital circuit, which test procedure using a logic probe can identify a faulty gate?

Accepted Answer

Apply all possible input combinations and compare the output to the truth table.

Answer

Apply a logic '0' to all inputs and observe the output.

Answer

Apply a logic '1' to all inputs and observe the output.

Question 16

Which logical expression corresponds to the truth table below?

| A | B | Output |   
|:---|:---|:---|
| 0 | 0 | 0 |
| 0 | 1 | 1 |
| 1 | 0 | 1 |
| 1 | 1 | 1 |

Accepted Answer

A OR B

Answer

A AND B

Answer

NOT A OR NOT B

Answer

A XOR B

Question 17

Which of the following is NOT a fundamental type of logic gate?

Accepted Answer

Flip-flop

Answer

AND gate

Answer

OR gate

Answer

NOT gate

Question 18

Which logic gate is known for its universal computing capabilities, allowing it to implement any other logic gate?

Accepted Answer

NAND

Answer

OR

Answer

AND

Answer

NOT

Question 19

When both inputs of an XOR gate are set to '1', what is the output?

Accepted Answer

0

Answer

1

Answer

X

Answer

Z

Question 20

Which Boolean expression correctly represents the output of a three-input AND gate where A, B, and C are the inputs?

Accepted Answer

A · B · C

Answer

A + B + C

Answer

¬(A ∨ B ∨ C)

Answer

A ⊕ B ⊕ C

Question 21

What is the primary function of a NOT gate?

Accepted Answer

Invert the input signal

Answer

Delay the input signal

Answer

Store the input signal

Answer

Amplify the input signal

Question 22

Which logic gate has the same truth table as a two-input NAND gate?

Accepted Answer

Two-input NOR gate

Answer

Two-input XOR gate

Answer

Two-input AND gate

Answer

Two-input OR gate

Question 23

In a combinational logic circuit, what determines the output at any given time?

Accepted Answer

Only the current input values

Answer

Only the past input values

Answer

Both the current and past input values

Question 24

Which of the following is a common application of logic gates?

Accepted Answer

Designing digital computers

Answer

Filtering analog signals

Answer

Generating radio waves

Answer

Amplifying audio signals

Question 25

Complete the truth table for a two-input OR gate:

Accepted Answer

A B | Q
0 0 | 0
0 1 | 1
1 0 | 1
1 1 | 1

Answer

A B | Q
0 0 | 0
0 1 | 0
1 0 | 0
1 1 | 1

Answer

A B | Q
0 0 | 1
0 1 | 1
1 0 | 1
1 1 | 0

Question 26

Which type of programmable logic device allows users to reconfigure its internal logic circuits?

Accepted Answer

Field-Programmable Gate Array (FPGA)

Answer

Transistor

Answer

Capacitor

Answer

Diode

Question 27

What is the output of a 3-input AND gate when one input is high and the other two are low?

Accepted Answer

Low

Answer

Intermediate

Answer

High

Answer

Depends on the specific gate

Question 28

What type of logic gate is used to implement the majority function?

Accepted Answer

Majority gate

Answer

XOR gate

Answer

NAND gate

Answer

Buffer gate

Question 29

Which of the following is NOT a characteristic of a CMOS logic gate?

Accepted Answer

High power consumption

Answer

High noise immunity

Answer

Complementary inputs and outputs

Answer

Low propagation delay

Question 30

What is the purpose of a tri-state buffer?

Accepted Answer

To control the flow of data in a digital system

Answer

To convert analog signals to digital signals

Answer

To store data temporarily

Answer

To amplify the input signal

Question 31

What is the difference between combinational and sequential logic gates?

Accepted Answer

Combinational gates produce outputs based on current inputs only, while sequential gates store previous inputs to affect future outputs

Answer

Combinational gates are faster than sequential gates

Question 32

Which of the following Boolean expressions represents the output of a 4-input XOR gate?

Accepted Answer

A ⊕ B ⊕ C ⊕ D

Answer

A ⋅ B ⋅ C ⋅ D

Answer

(A + B) ⋅ (C + D)

Answer

A + B + C + D

Question 33

Which of the following gates is known as the universal gate and can implement any other logic gate?

Accepted Answer

NAND

Answer

AND

Answer

XOR

Answer

NOR

Question 34

What is the output of a 2-input AND gate when both inputs are '0' according to its truth table?

Accepted Answer

0

Answer

X

Answer

1

Answer

Z

Question 35

What is the equivalent Boolean expression for a 2-input OR gate?

Accepted Answer

A + B

Answer

A' + B'

Answer

A * B

Answer

A' * B'

Question 36

Which of the following circuit types solely consists of logic gates and produces an output based on the combination of its inputs without the use of memory elements?

Accepted Answer

Combinational logic circuit

Answer

Digital logic circuit

Answer

Analog logic circuit

Answer

Sequential logic circuit

Question 37

What is the primary purpose of using a Schmitt trigger in digital circuits?

Accepted Answer

To eliminate noise and improve signal integrity

Answer

To store data

Answer

To generate clock pulses

Answer

To amplify analog signals

Question 38

What is the function of a demultiplexer in digital circuits?

Accepted Answer

To distribute a single input to multiple separate outputs based on a select line

Answer

To store data

Answer

To combine multiple inputs into a single output

Answer

To generate clock pulses

Question 39

Which of the following devices is a type of programmable logic device (PLD) that allows for the implementation of custom logic functions?

Accepted Answer

PAL (Programmable Array Logic)

Answer

RAM (Random Access Memory)

Answer

Microprocessor

Answer

ROM (Read-Only Memory)

Question 40

What is the main advantage of utilizing logic gates instead of individual discrete transistors in digital circuit design?

Accepted Answer

Simplified design, reduced component count, and enhanced reliability

Answer

Improved performance and speed

Answer

Lower cost and power consumption

Answer

Increased flexibility and customization

Question 41

Which of the following logic gates is considered a universal logic gate, capable of implementing any other logic function?

Accepted Answer

NAND

Answer

OR

Answer

AND

Answer

NOR

Question 42

A logic gate with two inputs, labeled A and B, that performs the logical AND operation is referred to as:

Accepted Answer

AND gate

Answer

OR gate

Answer

NOT gate

Question 43

In an XOR gate, the output becomes '1' when:

Accepted Answer

The inputs have different logic levels (one is '0' and the other is '1')

Answer

The inputs have the same logic level

Answer

Both inputs are at logic level '1'

Answer

Both inputs are at logic level '0'

Question 44

Which characteristic is NOT associated with CMOS (Complementary Metal-Oxide-Semiconductor) logic gates?

Accepted Answer

High power consumption

Answer

Complementary inputs

Answer

Low propagation delay

Answer

High noise immunity

Question 45

In a digital circuit, a NOT gate serves the purpose of:

Accepted Answer

Inverting the input signal, changing '0' to '1' and vice versa

Answer

Amplifying the input signal

Answer

Storing data

Answer

Generating a clock signal

Question 46

The truth table for a 3-input NAND gate has a total of:

Accepted Answer

8 rows

Answer

4 rows

Answer

2 rows

Answer

16 rows

Question 47

Which of the following Boolean expressions correctly represents the output of a 2-input XOR gate, where A and B are the inputs and Q is the output?

Accepted Answer

Q = A'B + AB'

Answer

Q = AB + A'B'

Answer

Q = A'B

Answer

Q = A + B

Question 48

Which of the following is the universal logic gate that can implement any other Boolean function?

Accepted Answer

NAND

Answer

AND

Answer

NOT

Answer

OR

Question 49

What is the output of a 2-input AND gate when both inputs are '0'? Write this in terms of a function that takes two Boolean inputs.

Accepted Answer

0

Answer

Not defined

Answer

1

Question 50

Define a combinational circuit, clearly stating how its output is determined.

Accepted Answer

A combinational circuit is a digital logic circuit whose output depends solely on its current inputs.

Answer

A circuit that stores information in memory

Answer

A circuit that uses feedback to control its behavior

Question 51

Provide an example of a real-world application where logic gates are utilized.

Accepted Answer

Microprocessors

Answer

Capacitors

Answer

Diodes

Answer

Transistors

Question 52

Explain the difference between a positive logic system and a negative logic system.

Accepted Answer

In a positive logic system, a high voltage represents a true value, while in a negative logic system, a low voltage represents a true value.

Answer

Positive logic systems use more power than negative logic systems

Question 53

Describe the purpose of a Schmitt trigger and its application in digital circuits.

Accepted Answer

A Schmitt trigger is a digital circuit that eliminates noise from a digital signal.

Answer

To convert an analog signal to a digital signal

Answer

To store data in memory

Answer

To amplify a digital signal

Question 54

What is the output of a 3-input NAND gate when all three inputs are '1'?

Accepted Answer

0

Answer

Not defined

Answer

1