Electronics Combinational Logic Circuits Questions and Answers
Practice ModeShowing 10 of 29 questions
Q11
Which of the following is an example of a combinational circuit?
Answer: Option C
Explanation: Flip-flops are sequential circuits while others are combinational.
Q12
What is the output of a half adder when both inputs are 1?
Answer: Option C
Explanation: Half adder: Sum = A XOR B, Carry = A AND B
Q13
How many inputs does a full adder have?
Answer: Option C
Explanation: Full adder has 3 inputs: A, B, and Carry-in
Q14
What is the main difference between combinational and sequential circuits?
Answer: Option B
Explanation: Sequential circuits have memory while combinational do not.
Q15
Which gate is primarily used in parity generators?
Answer: Option C
Explanation: XOR gates are used for parity generation and checking.
Q16
What does a multiplexer do?
Answer: Option C
Explanation: Multiplexer selects one of many input lines to single output.
Q17
How many select lines are needed for a 8-to-1 multiplexer?
Answer: Option C
Explanation: 2^n = number of inputs, so 2^3=8 needs 3 select lines
Q18
What is the function of a decoder?
Answer: Option A
Explanation: Decoder converts binary code to output lines.
Q19
How many output lines does a 3-to-8 decoder have?
Answer: Option D
Explanation: 3-to-8 decoder has 8 output lines (2^3=8)
Q20
What is a priority encoder?
Answer: Option A
Explanation: Priority encoder gives priority to highest order input.