ALU 101 Digital Logic Gates 1 — Questions and Answers
Question 1: Which logic gate outputs HIGH only when all its inputs are HIGH?
- AND (Correct answer)
- OR
- NAND
- XOR
Correct answer: AND
An AND gate produces a HIGH (1) output only when every input is HIGH (1).
Question 2: What is the output of a NOT gate when the input is 0?
- 0
- 1 (Correct answer)
- Undefined
- High-impedance
Correct answer: 1
A NOT gate (inverter) complements its input, so an input of 0 produces an output of 1.
Question 3: Which gate is the complement of the AND gate?
- OR
- XOR
- NAND (Correct answer)
- XNOR
Correct answer: NAND
A NAND gate produces the complement of the AND gate's output, outputting LOW only when all inputs are HIGH.
Question 4: An XOR gate outputs HIGH when its two inputs are:
- Both 0
- Both 1
- Different (Correct answer)
- Same
Correct answer: Different
An XOR (exclusive OR) gate outputs 1 only when its inputs differ from each other.
Question 5: How many input combinations does a 3-input AND gate have?
- 4
- 6
- 8 (Correct answer)
- 16
Correct answer: 8
A 3-input gate has 2³ = 8 possible input combinations.
Question 6: Which logic gate is considered a universal gate?
- AND
- OR
- XOR
- NAND (Correct answer)
Correct answer: NAND
NAND is a universal gate because any other logic gate (AND, OR, NOT, etc.) can be implemented using only NAND gates.
ALU 101 Digital Logic Gates 1
Which logic gate outputs HIGH only when all its inputs are HIGH?