What is a combinational circuit?
A) A circuit with feedback
B) A circuit with memory elements
C) A circuit without feedback
D) A circuit with sequential logic
Answer: C
Which of the following is NOT a characteristic of combinational circuits?
A) Memory
B) Feedback
C) Output depends only on current inputs
D) No memory elements used
Answer: B
What is the primary function of a decoder in a combinational circuit?
A) Output multiple signals based on input
B) Store data temporarily
C) Perform arithmetic operations
D) Provide feedback to inputs
Answer: A
What is the main purpose of a multiplexer in combinational logic?
A) Convert analog signals to digital
B) Combine multiple signals into one
C) Generate clock signals
D) Store data for later use
Answer: B
Which gate is commonly used for arithmetic operations in combinational circuits?
A) XOR gate
B) AND gate
C) OR gate
D) NAND gate
Answer: A
What is the truth table for an AND gate with two inputs?
A) 0 0 1 1
B) 0 1 1 1
C) 0 0 0 1
D) 0 1 1 0
Answer: C
What is the truth table for an XOR gate with two inputs?
A) 0 0 1 1
B) 0 1 1 0
C) 0 0 0 1
D) 0 1 1 1
Answer: D
Which gate can be used to implement the NOT operation in combinational circuits?
A) XOR gate
B) AND gate
C) OR gate
D) NAND gate
Answer: D
What is the output of an OR gate if both inputs are LOW (0)?
A) HIGH (1)
B) LOW (0)
C) Unknown
D) Depends on gate configuration
Answer: B
What is the output of a NAND gate if one input is HIGH (1) and the other is LOW (0)?
A) HIGH (1)
B) LOW (0)
C) Unknown
D) Depends on gate configuration
Answer: A
What is the output of a NOR gate if both inputs are LOW (0)?
A) HIGH (1)
B) LOW (0)
C) Unknown
D) Depends on gate configuration
Answer: A
Which gate can be used to implement any logic function in combinational circuits?
A) NAND gate
B) NOR gate
C) XOR gate
D) NOT gate
Answer: A
What is the output of an XOR gate if both inputs are HIGH (1)?
A) HIGH (1)
B) LOW (0)
C) Unknown
D) Depends on gate configuration
Answer: B
What is the output of an XOR gate if one input is LOW (0) and the other is HIGH (1)?
A) HIGH (1)
B) LOW (0)
C) Unknown
D) Depends on gate configuration
Answer: A
What is the primary function of a full adder in a combinational circuit?
A) Add two binary numbers
B) Store data temporarily
C) Generate clock signals
D) Perform logical operations
Answer: A
What is the output of a full adder if the inputs are
𝐴
=
1
,
𝐵
=
1
,
A=1,B=1, and
𝐶
in
=
1
C
in
=1?
A)
𝑆
=
0
,
𝐶
out
=
1
S=0,C
out
=1
B)
𝑆
=
1
,
𝐶
out
=
0
S=1,C
out
=0
C)
𝑆
=
1
,
𝐶
out
=
1
S=1,C
out
=1
D)
𝑆
=
0
,
𝐶
out
=
0
S=0,C
out
=0
Answer: C
Which gate is commonly used in priority encoder circuits?
A) XOR gate
B) AND gate
C) OR gate
D) NAND gate
Answer: B
What is the primary purpose of a priority encoder in a combinational circuit?
A) Convert analog signals to digital
B) Combine multiple signals into one
C) Generate clock signals
D) Encode priority levels into binary code
Answer: D
Which gate is used for comparison operations in digital circuits?
A) XOR gate
B) AND gate
C) OR gate
D) NAND gate
Answer: A
What is the output of a comparator circuit if
𝐴
>
𝐵
A>B?
A) HIGH (1)
B) LOW (0)
C) Unknown
D) Depends on gate configuration
Answer: A