Courses

# Logic Gates Class 12 Notes | EduRev

## Class 12 : Logic Gates Class 12 Notes | EduRev

The document Logic Gates Class 12 Notes | EduRev is a part of the Class 12 Course Physics Class 12.
All you need of Class 12 at this link: Class 12

Logic Gate

A digital circuit which allows a signal to pass through it, only when few logical relations are satisfied, is called a logic gate.

Truth Table

A table which shows all possible input and output combinations is called a truth table.

Basic Logic Gates

(i) OR Gate It is a two input and one output logic gate. Boolean expression Y = A + B (Y equals A OR B)

(ii) AND Gate It is a two input and one output logic gate Boolean expression Y = A . B (Y equals A AND B)

(iii) NOT Gate It is a one input and one output logic gate. Combination of Gates

(i) NAND Gate When output of AND gate is applied as input to a NOT gate, then it is called a NAND gate. Boolean expression Y = A * B (Y equals negated of A AND B)

(ii) NOR Gate When output of OR gate is applied as input to a NOT gate, then it is called a NOR gate. Boolean expression Y = A + B ( Y equals negated of A OR B)

• The Boolean expression obey commutative law associative law as well as distributive law.
1. A + B = B+ A
2. A· B = B· A
3. A + (B + C) = (A + B) + C
• Demorgan’s theorems ,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

;