## 50+ Top Digital Design Multiple Choice Questions with Answers

### What is the fundamental building block of digital circuits?

a) Transistor.

b) Diode.

c) Capacitor.

d) Resistor.

Answer: a) Transistor

### What does the term “logic level” represent in digital electronics?

a) The voltage range used to represent binary values

b) The maximum current a digital circuit can handle

c) The speed at which a digital circuit operates

d) The logic gate used in a digital circuit

Answer: a) The voltage range used to represent binary values

### Which number system is commonly used in digital electronics?

a) Binary

b) Decimal

c) Hexadecimal

d) Octal

Answer: a) Binary

### In binary, what does a “1” represent?

a) High voltage

b) Low voltage

c) Ground

d) Open circuit

Answer: a) High voltage

### How many bits are in a byte?

a) 4

b) 8

c) 16

d) 32

Answer: b) 8

### Which logic gate performs the Boolean AND operation?

a) OR gate

b) NOT gate

c) NAND gate

d) AND gate

Answer: d) AND gate

### The output of an OR gate is HIGH when:

a) All inputs are LOW

b) Any input is HIGH

c) All inputs are HIGH

d) None of the inputs are connected

Answer: b) Any input is HIGH

### What is the complement of a binary number 1010?

a) 1010

b) 0101

c) 1101

d) 0110

Answer: b) 0101

### Which logic gate is an inverted OR gate?

a) OR gate

b) NOT gate

c) NAND gate

d) AND gate

Answer: c) NAND gate

A half-adder adds:

a) Two binary numbers and a carry-in

b) Two binary numbers without a carry-in

c) Two decimal numbers and a carry-in

d) Two decimal numbers without a carry-in

Answer: b) Two binary numbers without a carry-in

### How many input combinations are possible in a 2-input logic gate?

a) 2

b) 3

c) 4

d) 8

Answer: c) 4

### Which logic gate is equivalent to an inverted AND gate?

a) OR gate

b) NOT gate

c) NAND gate

d) XOR gate

Answer: c) NAND gate

### The binary number “1011” is equivalent to which decimal number?

a) 5

b) 8

c) 10

d) 11

Answer: d) 11

### Which logic gate is used for addition in binary arithmetic?

a) AND gate

b) OR gate

c) XOR gate

d) NAND gate

Answer: c) XOR gate

### What is the result of the binary subtraction: 1001 – 0110?

a) 0011

b) 0101

c) 1010

d) 1101

Answer: a) 0011

### What does TTL stand for in digital electronics?

a) Time To Learn

b) Transistor-Transistor Logic

c) Time To Live

d) Transistor-Transformer Logic

Answer: b) Transistor-Transistor Logic

### Which logic gate is used to perform binary multiplication?

a) AND gate

b) OR gate

c) XOR gate

d) NAND gate

Answer: a) AND gate

### What is the function of a decoder in digital circuits?

a) Performs arithmetic operations

b) Converts binary codes into a more complex format

c) Converts binary codes into decimal numbers

d) Converts binary codes into their respective outputs

Answer: d) Converts binary codes into their respective outputs

### A 3-input OR gate will output HIGH if:

a) All inputs are LOW

b) Any input is HIGH

c) All inputs are HIGH

d) Only one input is HIGH

Answer: b) Any input is HIGH

### The hexadecimal number “A3” is equivalent to which binary number?

a) 10100100

b) 11000011

c) 10100011

d) 10110100

Answer: c) 10100011

### What does the term “propagation delay” mean in digital circuits?

a) The time taken to complete one clock cycle

b) The time taken for a signal to propagate through a circuit

c) The time taken for a digital circuit to power up

d) The time taken for a logic gate to change its state

Answer: b) The time taken for a signal to propagate through a circuit

### Which logic gate is used for creating a digital memory element?

a) AND gate

b) OR gate

c) Flip-flop

d) XOR gate

Answer: c) Flip-flop

### What is the output of an XOR gate when both inputs are the same?

a) High

b) Low

c) Floating

d) Indeterminate

Answer: b) Low

### Which logic gate is used in binary subtraction?

a) AND gate

b) OR gate

c) XOR gate

d) NAND gate

Answer: c) XOR gate

### The binary number “1110” is equivalent to which decimal number?

a) 5

b) 9

c) 12

d) 13

Answer: d) 13

### What is the result of the binary addition: 1011 + 0101?

a) 10010

b) 1110

c) 11010

d) 100

Answer: c) 11010

### What does CMOS stand for in digital electronics?

a) Complementary Metal-Oxide Semiconductor

b) Continuous Metal-Oxide Semiconductor

c) Conventional Metal-Oxide Semiconductor

d) Complimentary Mode-Oscillator System

Answer: a) Complementary Metal-Oxide Semiconductor

### Which logic gate is used to perform binary division?

a) AND gate

b) OR gate

c) XOR gate

d) NAND gate

Answer: d) NAND gate

### The octal number “36” is equivalent to which binary number?

a) 011101

b) 111110

c) 011110

d) 111001

Answer: c) 011110

### How many input combinations are possible in a 3-input logic gate?

a) 6

b) 7

c) 8

d) 9

Answer: c) 8

### Which logic gate is used as a basic memory cell in RAM?

a) AND gate

b) OR gate

c) Flip-flop

d) XOR gate

Answer: c) Flip-flop

### The binary number “1101” is equivalent to which decimal number?

a) 5

b) 9

c) 12

d) 13

Answer: d) 13

### Which logic gate is used for creating a counter in digital circuits?

a) AND gate

b) OR gate

c) Flip-flop

d) XOR gate

Answer: c) Flip-flop

### In a 4-bit binary system, what is the highest decimal number that can be represented?

a) 7

b) 8

c) 15

d) 16

Answer: c) 15

### What is the output of a NOR gate when both inputs are LOW?

a) High

b) Low

c) Floating

d) Indeterminate

Answer: a) High

### Which logic gate is used for binary comparator circuits?

a) AND gate

b) OR gate

c) Flip-flop

d) XOR gate

Answer: d) XOR gate

### The binary number “100110” is equivalent to which octal number?

a) 56

b) 46

c) 32

d) 22

Answer: b) 46

### What is the result of the binary division: 1100 ÷ 0110?

a) 10

b) 11

c) 100

d) 101

Answer: b) 11

### Which logic gate is used to perform binary exponentiation?

a) AND gate

b) OR gate

c) XOR gate

d) NAND gate

Answer: c) XOR gate

### What does the term “fan-out” mean in digital electronics?

a) The number of inputs a logic gate can handle

b) The number of outputs a logic gate can handle

c) The maximum speed of a digital circuit

d) The power consumption of a digital circuit

Answer: b) The number of outputs a logic gate can handle

### The binary number “101010” is equivalent to which hexadecimal number?

a) 2A

b) 54

c) 3A

d) 2E

Answer: a) 2A

### What is the output of a NOT gate when the input is HIGH?

a) High

b) Low

c) Floating

d) Indeterminate

Answer: b) Low

### Which logic gate is used for creating a multiplexer in digital circuits?

a) AND gate

b) OR gate

c) Flip-flop

d) XOR gate

Answer: d) XOR gate

### The binary number “11111111” is equivalent to which decimal number?

a) 63

b) 127

c) 255

d) 512

Answer: c) 255

### What is the result of the binary multiplication: 1101 × 0110?

a) 101110

b) 10101

c) 100100

d) 10010

Answer: c) 100100

### In a digital circuit, what does the term “clock” represent?

a) A logic gate used for synchronization

b) A pulse signal that synchronizes circuit operations

c) A type of flip-flop

d) A logic gate used for counting

Answer: b) A pulse signal that synchronizes circuit operations

### Which logic gate is used for creating a demultiplexer in digital circuits?

a) AND gate

b) OR gate

c) Flip-flop

d) XOR gate

Answer: a) AND gate

### The binary number “1110011” is equivalent to which octal number?

a) 123

b) 71

c) 63

d) 43

Answer: c) 63

### What is the result of the binary exponentiation: 1010 ^ 0101?

a) 1010

b) 0101

c) 1111

d) 10000

Answer: c) 1111

### Which logic gate is used in a digital circuit to store one bit of data?

a) AND gate

b) OR gate

c) Flip-flop

d) XOR gate

Answer: c) Flip-flop