Which logical gate is known as Universal gate?
2021
Which logical gate is known as Universal gate?
- A.
AND
- B.
Ex-OR
- C.
NOT
- D.
NAND
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Correct answer: D
The NAND gate is known as a Universal gate because it can be used to construct all other basic logic gates (AND, OR, NOT).
Step 1: To create a NOT gate, connect both inputs of a NAND gate together. This gives the inverse of the input.
Step 2: To create an AND gate, use a NAND gate followed by a NOT gate (made from another NAND).
Step 3: To create an OR gate, use De Morgan's theorem: A OR B = NOT((NOT A) AND (NOT B)). This can be implemented using NAND gates.
Since NAND can implement NOT, AND, and OR, it is universal.