# AND gate is formed by using two? 1)OR 2)NAND 3)NOT 4)NOR

##### 2 Answers

Euhhh...

As far as I am aware...

None of the above.

#### Explanation:

The simplest Boolean "gate" is the **identity:**

Simplest: what comes in, goes out....

So simple, that it actually doesn't change anything and usually is forgotten/ignored. Compare it to a simple strip of copperwire...

The other basic gates:

The **Equals** (Identity), **NOT** , **AND**, **OR** and **XOR** (Exclusive OR) are the basic, elementary gates/operators in Boolean Algebra.

So you can't really construct an **AND** -gate from any other ones.....

AND gate is formed by using two NAND gates.

#### Explanation:

NAND and NOR gates are called "Universal" gates as any kind of logic gate can be obtained by using combinations of these.

To get an AND gate we can use two NAND gates.

If A and B are the input to the first NAND gate, we will get output as

Let this be denoted by

Now give

Now the output of second NAND gate will be :

**Note:** AND logic can also be obtained by using **3 NOR** gates. But as the question says about a specific number **two** , we need to use NAND gates.